Real Time Test in situ of Superalloy Oxide Scale Stress by Archimedes Curve Slice Moment Technique

Stress is the direct cause of surface oxide scale exfoliation to ruin the protection for alloy matrix. Therefore, it is the key to study oxide scale mechanical behaviour for discovering the oxidation resistance of alloys. In this paper, a new kind of experimental method ‘Archimedes curve slice momen...

Full description

Saved in:
Bibliographic Details
Published in:Металлофизика и новейшие технологии
Date:2016
Main Authors: Hai-tao Wang, Shao-mei Zheng, Hua-shun Yu
Format: Article
Language:English
Published: Інститут металофізики ім. Г.В. Курдюмова НАН України 2016
Subjects:
Online Access:https://nasplib.isofts.kiev.ua/handle/123456789/112644
Tags: Add Tag
No Tags, Be the first to tag this record!
Journal Title:Digital Library of Periodicals of National Academy of Sciences of Ukraine
Cite this:Real Time Test in situ of Superalloy Oxide Scale Stress by Archimedes Curve Slice Moment Technique / Hai-tao Wang, Shao-mei Zheng, Hua-shun Yu // Металлофизика и новейшие технологии. — 2016. — Т. 38, № 12. — С. 1635-1654. — Бібліогр.: 14 назв. — англ.

Institution

Digital Library of Periodicals of National Academy of Sciences of Ukraine
_version_ 1860164902813958144
author Hai-tao Wang
Shao-mei Zheng
Hua-shun Yu
author_facet Hai-tao Wang
Shao-mei Zheng
Hua-shun Yu
citation_txt Real Time Test in situ of Superalloy Oxide Scale Stress by Archimedes Curve Slice Moment Technique / Hai-tao Wang, Shao-mei Zheng, Hua-shun Yu // Металлофизика и новейшие технологии. — 2016. — Т. 38, № 12. — С. 1635-1654. — Бібліогр.: 14 назв. — англ.
collection DSpace DC
container_title Металлофизика и новейшие технологии
description Stress is the direct cause of surface oxide scale exfoliation to ruin the protection for alloy matrix. Therefore, it is the key to study oxide scale mechanical behaviour for discovering the oxidation resistance of alloys. In this paper, a new kind of experimental method ‘Archimedes curve slice moment technique’ is studied to test in situ the real time oxide scale stress of ferro-based superalloy K273 during all the high-temperature oxidation. By the derived formula, the oxide scale stress σ can be calculated precisely only by observing Archimedes curve slice real-time polar radius OC′. Having been oxidated for 5 hours at 800°C, the oxide scale stress versus oxidation time is regressed to follow parabola equation strictly. As the oxides grow and the inner new oxides form in scales to press each other, the oxide scale stress is generated. Analysed by SEM, EDS and XRD, the oxide scale is compact composite structure made up of Cr₂O₃ and spinel (Fe, Ni, Mn)Cr₂O₄. The less oxide scale stress increment brings about the lower oxidation weight gain rate and the better oxidation resistance. Improved by the use of vacuum system, the Archimedes curve slice moment technique is going to test the oxide scale growing and thermal stresses qualitatively and quantitatively in situ all the time at high temperature. Напруження є безпосередньою причиною відшарування приповерхневої циндри, що призводить до руйнування захисту матриці стопу. Отже, вивчення механічної поведінки циндри є ключем до вивчення стійкости стопів до окиснення. В даній роботі розглянуто нову експериментальну методу міряння скручувального моменту для тонкого шару матеріялу, що був вирізаний за Архімедовою кривою, яка слугує для in situ дослідження в режимі реального часу напружень, що виникають через циндру у суперстопі на основі заліза K273 впродовж усього високотемпературного окиснення. Згідно з одержаним виразом, для точного розрахунку у режимі реального часу напружень σ, що виникають завдяки циндрі, достатньо лише спостереження за полярним радіюсом OC′ зразка, вирізаного за Архімедовою кривою. При дослідженні процесу окиснення протягом 5 годин за температури у 800°C залежність напружень через циндру від часу окиснення було зведено до рівняння параболи. По мірі росту оксиду та формування нових внутрішніх його шарів, які тиснуть один на одного, ґенеруються напруження за рахунок циндри. Аналіза, проведена методами СЕМ, ЕРС та РДА, показала, що циндра ущільнюється у композитну структуру, яка складається з Cr₂O₃ та шпінелі (Fe, Ni, Mn)Cr₂O₄. Зменшення напружень, що виникають за рахунок циндри, приводить до більш низької швидкости окиснення та підвищення стійкости до окиснення. Поліпшену використанням вакуумної системи методику in situ міряння скручувального моменту для зразків, вирізаних за Архімедовою кривою, якісно та кількісно перевірено шляхом дослідження зростання циндри та термічних напружень впродовж усього часу високотемпературного окиснення. Напряжения являются непосредственной причиной отслоения приповерхностной окалины, что приводит к разрушению защиты матрицы сплава. Следовательно, изучение механического поведения окалины является ключом к выяснению стойкости сплавов к окислению. В данной работе рассматривается новая экспериментальная методика измерения скручивающего момента для тонкого слоя материала, вырезанного по кривой Архимеда, служащая для in situ изучения в режиме реального времени напряжений, возникающих за счёт окалины, в суперсплаве на основе железа K273 в течение всего высокотемпературного окисления. Согласно полученному выражению, для точного расчёта в режиме реального времени напряжений σ, возникающих из-за окалины, достаточно лишь наблюдения за полярным радиусом OC′ образца, вырезанного по кривой Архимеда. При исследовании процесса окисления на протяжении 5 часов при температуре 800°C зависимость напряжений из-за окалины от времени окисления была сведена к уравнению параболы. По мере роста оксида и формирования новых внутренних его слоёв, давящих друг на друга, генерируются напряжения за счёт окалины. Анализ, проведённый методами СЭМ, ЭРС и РДА, показал, что окалина уплотняется в композитную структуру, состоящую из Cr₂O₃ и шпинели (Fe, Ni, Mn)Cr₂O₄. Уменьшение напряжений, возникающих за счёт окалины, приводит к более низкой скорости окисления и повышению стойкости к окислению. Улучшенная использованием вакуумной системы методика in situ измерения скручивающего момента для образцов, вырезанных по кривой Архимеда, качественно и количественно проверена путём исследования роста окалины и термических напряжений на протяжении всего времени высокотемпературного окисления.
first_indexed 2025-12-07T17:56:02Z
format Article
fulltext 1635 PACS numbers:68.35.Gy, 68.47.Gh,68.55.J-,68.55.Nq,68.60.Dv,81.65.Kn, 81.65.Mq Real Time Test in Situ of Superalloy Oxide Scale Stress by Archimedes Curve Slice Moment Technique Hai-tao Wang, Shao-mei Zheng, and Hua-shun Yu* College of Mechanical Engineering, Qingdao University of Technology, 11 Fushun Road, 266033 Qingdao, China *Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, 17923 Jingshi Road, 250061 Jinan, China Stress is the direct cause of surface oxide scale exfoliation to ruin the protec- tion for alloy matrix. Therefore, it is the key to study oxide scale mechanical behaviour for discovering the oxidation resistance of alloys. In this paper, a new kind of experimental method ‘Archimedes curve slice moment tech- nique’ is studied to test in situ the real time oxide scale stress of ferro-based superalloy K273 during all the high-temperature oxidation. By the derived formula, the oxide scale stress  can be calculated precisely only by observing Archimedes curve slice real-time polar radius OC. Having been oxidated for 5 hours at 800C, the oxide scale stress versus oxidation time is regressed to follow parabola equation strictly. As the oxides grow and the inner new ox- ides form in scales to press each other, the oxide scale stress is generated. Analysed by SEM, EDS and XRD, the oxide scale is compact composite struc- ture made up of Cr2O3 and spinel (Fe, Ni, Mn)Cr2O4. The less oxide scale stress increment brings about the lower oxidation weight gain rate and the better oxidation resistance. Improved by the use of vacuum system, the Archimedes curve slice moment technique is going to test the oxide scale growing and thermal stresses qualitatively and quantitatively in situ all the time at high temperature. Key words: ferro-based superalloy, oxide scale stress, oxidation resistance, Corresponding author: Hai-tao Wang E-mail: htwangsd@126.com Please cite this article as: Hai-tao Wang, Shao-mei Zheng, and Hua-shun Yu, Real Time Test in Situ of Superalloy Oxide Scale Stress by Archimedes Curve Slice Moment Technique, Metallofiz. Noveishie Tekhnol., 38, No. 12: 1635—1654 (2016), DOI: 10.15407/mfint.38.12.1635. Металлофиз. новейшие технол. / Metallofiz. Noveishie Tekhnol. 2016, т. 38, № 12, сс. 1635—1654 / DOI: 10.15407/mfint.38.12.1635 Оттиски доступны непосредственно от издателя Фотокопирование разрешено только в соответствии с лицензией 2016 ИМФ (Институт металлофизики им. Г. В. Курдюмова НАН Украины) Напечатано в Украине. 1636 Hai-tao WANG, Shao-mei ZHENG, and Hua-shun YU Archimedes curve. Напруження є безпосередньою причиною відшарування приповерхневої циндри, що призводить до руйнування захисту матриці стопу. Отже, ви- вчення механічної поведінки циндри є ключем до вивчення стійкости стопів до окиснення. В даній роботі розглянуто нову експериментальну методу міряння скручувального моменту для тонкого шару матеріялу, що був вирізаний за Архімедовою кривою, яка слугує для in situ дослідження в режимі реального часу напружень, що виникають через циндру у супер- стопі на основі заліза K273 впродовж усього високотемпературного окис- нення. Згідно з одержаним виразом, для точного розрахунку у режимі реального часу напружень , що виникають завдяки циндрі, достатньо лише спостереження за полярним радіюсом OC зразка, вирізаного за Ар- хімедовою кривою. При дослідженні процесу окиснення протягом 5 годин за температури у 800C залежність напружень через циндру від часу оки- снення було зведено до рівняння параболи. По мірі росту оксиду та фор- мування нових внутрішніх його шарів, які тиснуть один на одного, ґене- руються напруження за рахунок циндри. Аналіза, проведена методами СЕМ, ЕРС та РДА, показала, що циндра ущільнюється у композитну структуру, яка складається з Cr2O3 та шпінелі (Fe, Ni, Mn)Cr2O4. Змен- шення напружень, що виникають за рахунок циндри, приводить до більш низької швидкости окиснення та підвищення стійкости до окиснення. Поліпшену використанням вакуумної системи методику in situ міряння скручувального моменту для зразків, вирізаних за Архімедовою кривою, якісно та кількісно перевірено шляхом дослідження зростання циндри та термічних напружень впродовж усього часу високотемпературного окис- нення. Ключові слова: суперстоп на основі заліза, напруження, що виникають через циндру, стійкість до окиснення, Архімедова крива. Напряжения являются непосредственной причиной отслоения припо- верхностной окалины, что приводит к разрушению защиты матрицы сплава. Следовательно, изучение механического поведения окалины яв- ляется ключом к выяснению стойкости сплавов к окислению. В данной работе рассматривается новая экспериментальная методика измерения скручивающего момента для тонкого слоя материала, вырезанного по кривой Архимеда, служащая для in situ изучения в режиме реального времени напряжений, возникающих за счёт окалины, в суперсплаве на основе железа K273 в течение всего высокотемпературного окисления. Согласно полученному выражению, для точного расчёта в режиме реаль- ного времени напряжений , возникающих из-за окалины, достаточно лишь наблюдения за полярным радиусом OC образца, вырезанного по кривой Архимеда. При исследовании процесса окисления на протяжении 5 часов при температуре 800C зависимость напряжений из-за окалины от времени окисления была сведена к уравнению параболы. По мере роста оксида и формирования новых внутренних его слоёв, давящих друг на друга, генерируются напряжения за счёт окалины. Анализ, проведённый методами СЭМ, ЭРС и РДА, показал, что окалина уплотняется в компо- зитную структуру, состоящую из Cr2O3 и шпинели (Fe, Ni, Mn)Cr2O4. REAL TIME TEST IN SITU OF SUPERALLOY OXIDE SCALE STRESS 1637 Уменьшение напряжений, возникающих за счёт окалины, приводит к более низкой скорости окисления и повышению стойкости к окислению. Улучшенная использованием вакуумной системы методика in situ изме- рения скручивающего момента для образцов, вырезанных по кривой Ар- химеда, качественно и количественно проверена путём исследования ро- ста окалины и термических напряжений на протяжении всего времени высокотемпературного окисления. Ключевые слова: суперсплав на основе железа, напряжения, возникаю- щие за счёт окалины, стойкость к окислению, кривая Архимеда. (Received June 6, 2016) 1. INTRODUCTION During high temperature oxidation, stresses arise naturally with oxide scales forming on the surface of superalloys, forcing oxide scales to wrinkle, break or even exfoliate off the matrix. The existing of stress- es is the most important reason to ruin oxide scales and lose the oxida- tion resistance, so it greatly influenced on the life of superalloys in service. For a long time, researchers all over the world studied a lot for oxide scale stresses, many creative techniques were developed, among which pulling test [1—3], X-ray diffraction [4—6], and Raman spectros- copy [7—9] were the typical ones, making great efforts to study the generating mechanism of stresses and evaluate the protecting life of oxide scales for superalloys. Pulling test was the earliest research technique in exploring oxide scale mechanical properties, simple, direct, and primitive, mainly en- gaged in detecting the adhesive forth between oxide scale and matrix, but poor in probing oxide scale stresses in situ. The pulling force re- sults presented the comprehension of the adhesion strength with ma- trix and the binding strength by itself, a kind of static fuzzy data of multi forces, but not the accumulated dynamic stresses at real time in scales, so it was hard for real time test in situ of oxide scale stresses. X-ray diffraction was a kind of experimental method to detect the oxide scale stress indirectly. Although several decades went by, there were many uncertain factors and limitations to affect the oxide scale stress testing. X-ray diffraction could only measure the superficial stress, being insufficient for the thick oxide scale stress because of weak penetrability. In addition, the oxide scale stress was calculated by difference of diffraction peak drifting, which depended on the purity of materials. The diffraction peak matched with the standard PDF card without stress or impurity. Then, the exact testing of inner stress would be affected by impurity or multidisturbing of materials. There- fore, X-ray diffraction was only suitable for the oxide scale stress test- ing of pure structure precisely and qualitatively, but not for the multi 1638 Hai-tao WANG, Shao-mei ZHENG, and Hua-shun YU oxides or composite oxide scales. Raman spectroscopy also tested oxide scale stress indirectly; the spectra band choice, spectra peak precise location, laser penetration and material purity all limited the accurateness of stress testing. For composite oxide scale stress testing, Raman spectroscopy could only detect it roughly, such as the stress distribution or direction, while the stress qualitative or quantitative testing is insufficient. It is of great significance to study oxide scale stress of superalloys for its mechanical prediction in all kinds of conditions, theoretical cal- culation of strength, on-line controlling in use, life evaluation, and development of new high quality materials. How to test oxide scale stress scientifically is the key problem in the work, namely, by what means to measure the stress correctly and precisely. There is no way to illustrate the mechanism of oxide scale stress generating and scale ex- foliating without mechanical properties analyses accurately and quali- tatively. With long term of research work on ferro-based superalloys [10, 11], this paper studied a new technology called ‘Archimedes curve slice moment technique’, which is expected to realize the real time ox- ide scale stress testing of superalloys in situ. 2. EXPERIMENTAL PROCEDURE 2.1. Experiment Principle of Archimedes Curve Slice Moment Technique Archimedes curve is the trajectory running from circle centre at even velocity along radial and circumferential directions at the same time. As shown in Figure 1, let v be radial rate,  circumferential angular rate,  rotating angle at any point K,  the angle between tangent line KL and radial line KO, so the ratio of radial rate to linear rate is tg according to Archimedes curve characteristics: tg KO . v   (1) Let the time running from circle centre to any point K be t. Then, KO  vt,   t, and the formula (1) becomes (2): tg KO . vt t v v         (2) When the metal is made to be Archimedes curve slice, being fixed at the start point O and put horizontally, it will bend and deform by the oxide scale stress torque during high temperature oxidation. Three dimensional stresses at any point K on Archimedes slice surface come into being, as shown in Fig. 2, x is the tangent line longitudinal stress, REAL TIME TEST IN SITU OF SUPERALLOY OXIDE SCALE STRESS 1639 y the tangent line transversal stress, and z the normal line stress. Ox- ide scales grow on both front and back sides of Archimedes curve slice in the same oxidation conditions, so stresses at any point share the same size but different directions, which should be discussed accord- ing to different cases. For the normal line stress z, its direction varies with the first de- rivative dy/dx tendency of rectangular coordinates (x, y) on Archime- des curve, namely the positive or negative sign of the second derivative d2y/dx2. If the front side scale is convex, its dy/dx decreases gradual- ly, and d 2y/dx2  0; on the contrary, the concave scale on backside leads to increasing dy/dx, and d 2y/dx2  0. Therefore, at any point on Ar- chimedes curve slice, the oxide scale normal line stresses on front and Fig. 1. Track analysis of Archimedes curve. Fig. 2. Oxide scale stress analysis at any point K on Archimedes curve slice. 1640 Hai-tao WANG, Shao-mei ZHENG, and Hua-shun YU backsides share the same size and opposite directions, of which one is centripetal, and the other is centrifugal, as a result, there is no mo- ment on slice matrix because of normal line stresses counteracting at any point of Archimedes curve slice. For the tangent line longitudinal stress x, its direction is related to the first derivative dR/d of polar coordinate (R, ), namely the posi- tive or negative sign of the second derivative d 2R/d2. As shown in Figure 1, the radius R increases gradually along Archimedes curve slice: 2 2KO tg KB tg 1 1. sin sin cos v v v v R                  (3) Therefore, the first derivative of radius R at any point K was 2 1 dR v d      , increasing gradually with angle , nearly to be a con- stant v/, namely d 2R/d2  0. Therefore, at any point on Archimedes slice, the scale tangent line longitudinal stresses on front and back- sides share the same size and direction, that the acting forces on Ar- chimedes curve slice added each other. For the tangent line transversal stress y, its direction is always ver- tical to the longitudinal stress or the normal line stress, also vertical to the slice placing ground; so, there is no moment on Archimedes curve slice in the placing horizontal plane. In a word, among three dimensional direction stresses, only tangent line longitudinal stress x affects the slice bending in the placing hori- zontal plane. In the same oxidation conditions, the oxide scale thick- ness is even and same everywhere, and stresses at any point are iso- tropic, so the three dimensional stresses are equal in size, x  y  z. It is enough to study one dimension stress, and the Fig. 3. Oxide scale stress distribution of Archimedes curve slice. REAL TIME TEST IN SITU OF SUPERALLOY OXIDE SCALE STRESS 1641 synthetic stress is 1/2 S 3 .x   In order to deduce formula clearly, the tangent line longitudinal stress at any point is marked , as shown in Fig. 1, then, the effective stress on bending moment is sin, and the moment arm is KO: KO / ( / )tg .vt v v       (4) Therefore, the scale stress moment at any point K is M: sin KO sin tg . v M        (5) In formula (5),   arctg,  increases with the curve rotating angle . The stress and moment distribution along Archimedes curve slice are shown in Fig. 3 and Fig. 4, respectively. The stress  holds the same value all over the slice, and the moment varies from the minimum zero at start O to the matrix (v/) sin(arctg)tg(arctg) at the end D. So, the total moment M caused by oxide scale stresses on both front and back sides of the whole Ar- chimedes curve slice can be calculated by integrating in angle [0; ]: 2 0 0 0 2 12 1 0 0 2 2 2 0 2 0 sin tg sin 1 cos 2 2 2 1 (1 )1 (1 tg ) 2 2 2 [ 1 log( 1)] . 1 v v v M d d d vv d d v v d                                                                   (6) Fig. 4. Oxide scale stress moment distribution of Archimedes curve slice. 1642 Hai-tao WANG, Shao-mei ZHENG, and Hua-shun YU Arc length is the product of radius and radian in a circle, hence the Archimedes curve arc differentiation is: L KO . v d d vtd d        (7) The Archimedes curve slice length integrated in angle [0; ] is: 2 0 0 ( /2) . v v L d          (8) The Archimedes curve slice deformed to bend in the horizontal plane by oxide scale stress with fixed total length and changing parameters radial rate v, angular rate  and rotating angle range , as shown in Fig. 5, they turn from v1, 1, 0 to be v2, 2, 0   respectively, in which  is the net angle variation, hence formula (8) is deduced to be: 0 2 2 1 01 1 0 1 1 ( /2) , 2 vv L        (9) 0 2 2 2 02 2 0 2 2 ( ) ( /2) , 2 vv L           (10) L1  L2, (11) 2 2 1 0 1 2 0 2 /(2 ) ( ) /(2 ),v v       (12) 0 1 1 0 2 2 / ( ) / ,v v       (13) 0 1 1 2 2 2 2 0 1 2 2 1 ( / / ) / / ( ( )/( ) 1).v v v v v            (14) Fig. 5. The bending displacement of Archimedes curve slice by oxide scale stress. REAL TIME TEST IN SITU OF SUPERALLOY OXIDE SCALE STRESS 1643 When metal bends by force, the torque T and the angle  follows the formula (15):   , TL EI (15) where E–metal elastic modulus, L–metal length, I–sectional mo- ment of inertia (I  bh 3/12), b–metal width, h–metal thickness. Archimedes curve slice stops to bend with the total moment balance, meanwhile, the curve slice torque T is equal to the scale stress accumu- lated moment M : .T M  (16) T can be obtained by solving formulas (9), (14) and (15):                        3 31 2 1 2 0 1 2 1 2 1 2 0 10 1 1 1 1 12 . 6/(2 ) v vbh E Ebh v vEI T L vv (17) When curve slice rotates angle  by scale stress, namely in the area [0; 0  ], the accumulated oxide scale stress moment M can be calculated by formula (6):                                          00 2 2 2 2 2 2 22 00 2 2 2 0 0 0 0 2 2 [ 1 log( 1)] 1 (18) (OC) [( ) ( ) 1 log( ( ) 1)]. v v S M d b v For 0 0 0 1 2 2 1 0 1 2 2 1( ( ) / ( ) 1) ( ) / ( )v v v v              , (19) one can solve formula (18):                                             2 2 2 0 0 0 0 2 2 1 2 1 2 1 2 1 22 2 0 0 0 0 2 2 1 2 1 2 1 2 1 (OC) [( ) ( ) 1 log( ( ) 1)] (20) (OC) 1 log( 1) . M b v b v v v v v v v v v 1644 Hai-tao WANG, Shao-mei ZHENG, and Hua-shun YU It is possible to deduce a formula (16) by (17) and (20) as follows: 3 1 1 2 2 1 22 1 2 1 2 0 0 0 1 2 2 1 2 1 21 2 1 2 0 0 2 1 2 1 ( ( ) /( ) 1) (OC) [ 1 6 log( 1)], Ebh v v b v v v v v v v v v v                           (21) 1 23 1 1 2 2 1 0 1 2 1 1 2 1 2 1 2 1 22 2 0 0 0 0 2 1 2 1 2 1 2 1 ( ( ) / ( ) 1) 6 (OC) 1 log( 1) . v Eh v v v v v v v v v v v                                  (22) In experiment, with the Archimedes curve slice scrimping, the radi- us OC at the rotating angle   2 could be observed at real time. OC  v2t  v2(2/); so, 2 2 OC , 2 v     (23) v1/1 is the ratio of the initial radial velocity to the angular velocity, and the start length of Archimedes curve slice OC is OC  v1t   v1(2/), hence,    1 1 OC 2 v . (24) Therefore, formula (22) turns to be:   1 3 2 0 1 2 2 0 0 0 0 2 ( (OC)/(OC ) 1) 3 (OC) (OC ) OC OC OC OC 1 log( 1) . OC OC OC OC Eh                           (25) The synthetic stress is 1/2 3 times of the tangent line longitudinal stress of Archimedes curve slice. Thus,   1 3 2 0 1 2 2 0 0 0 0 2 3 ( (OC)/(OC ) 1) 3 (OC) (OC ) OC OC OC OC 1 log( 1) , OC OC OC OC Eh                           (26) in which,  is oxide scale stress, E–slice metal elastic modulus, h– Archimedes curve slice thickness, OC–Archimedes curve slice initial polar radius, OC–Archimedes curve slice real time polar radius, 0– REAL TIME TEST IN SITU OF SUPERALLOY OXIDE SCALE STRESS 1645 Archimedes curve slice initial rotating angle. From above all, the scale stress  at any point of Archimedes curve slice could be calculated by equation (26) precisely only by observing OC length at real time in situ with that the other factors are given. 2.2. Scheme Implementation (1) Making of Archimedes curve slice samples. The standard superal- loy K273 with the composition Fe80Cr20Ni5Mn5 was selected to be the test alloys. At first, the purchased 30 mm superalloy round bar was melted and cast to be 10010 mm roughcasts by high frequency in- duction furnace TX-25, then the roughcasts were machined to be 1005 mm thick plates by X52K milling machine, and the plates were wire cut by DK7740F to be Archimedes curve slice at last, as shown in Fig. 6, of which the thickness was h  0.4 mm, width b  5 mm, initial radius velocity v1  2.5 mm/s, initial rotating angle velocity 1  0.314 s 1, 0  2, surface roughness no less than Ra  0.8 m. Before being milling machined, the roughcasts were heated to 950C for 5 hours, then cooled in furnace, eliminating the cast or structure stresses by complete annealing, after that rough machining and finish machining went on. Before wire cutting with no inner stress by elec- tric-chemical machining, samples were annealed again at lower tem- perature 200C to 300C to remove mechanical machining stress. Such process guaranteed that there was no stress concentration in Archime- des curve slice to prevent the influence on the oxide scale mechanical properties detecting. Before high temperature oxidation, slice samples surface were washed clean by alcohol, no milling or polishing by emery paper in case of stress concentration on sample surface. (2) Oxide scale stress testing. Ferro-based superalloy scale stress was Fig. 6. Specimen of Archimedes curve slice. 1646 Hai-tao WANG, Shao-mei ZHENG, and Hua-shun YU tested using oxide scale stress testing apparatus of Archimedes curve slice sample. As shown in Figure 7, the apparatus was made up of heat- ing system SX2-8-13, temperature control system KYT, reading mi- croscope JC-10, platinum rhodium thermocouple and so on. At first, the slice sample placed in resistance furnace were heated quickly to testing temperature, recording its beginning displacement OC, then, it was oxidated at the constant temperature, and the oxide scale growing stress came into being, resulting in sample slice deforming to bend, meanwhile, the scale stress was calculated by equation (26) with re- cording the displacement OC of slice directly at any oxidation real time. (3) Oxide scale characterizations. After high-temperature oxidation, the oxidation weight gain was weighed to evaluate the oxidation re- sistance of superalloys by automatic photoelectric analysis level TG3288 10 4 g according to Chinese Standard HB5258-2000. The mor- phology and structure of oxide scales were analysed by JSM-5800 type scan electrical microscope (SEM). The elements existing in oxide scales were detected by Oxford INCA sight X energy disperse spectroscope (EDS). The oxide scales composi- tion was tested by Rigaku Horizontal X-ray diffractometer (XRD) with use of radiation CuK, 40 kV accelerating voltage, and 100 mA cur- rent. Fig. 7. Oxide scale stress testing apparatus of Archimedes curve slice sample: 1–KYT Temperature controller, 2–SX2-8-13 Resistance furnace, 3–JC-10 Reading microscope, 4–high temperature glass watching window, 5– Archimedes curve slice sample, 6–sample fixing station, 7–platinum rhodi- um thermocouple. REAL TIME TEST IN SITU OF SUPERALLOY OXIDE SCALE STRESS 1647 3. RESULTS AND DISCUSSION Having been oxidated at 800C for 5 hours, the scale stresses of differ- ent oxidation time were calculated and the curve versus time was plot- ted in Fig. 8. Scale stresses increased gradually with time at high tem- perature, but the increment in each oxidation time decreased step by step, as shown, the slop of the curve was steeper at the beginning but trailed off later. Regressing the stress data by the least square method and curve fit- ting, the equations were listed in Table 1, the curve of scale stress ver- sus time followed the parabolic law (  a)2  bt. The significance of regression equations and parameters in Table 1 were evaluated. Given the significant level   0.05 for the curve of scale stress ver- sus time at 800C, F test for regression equation was calculated: 2 2 2 2 0.9611 ( 2) (5 2) 36.3. 1 1 0.9611 R F n R        F distribution critical value was consulted in mathematical statistics: F(1, n  2)  10.13. For F  F(1, n  2), hypothesis H0 was refused, and H1 was obtained. The regression equation of test alloy (  3.1015)2  38.8391t was sig- nificant, and the curve confidence level arrived at 95%. The regression equation coefficient t was calculated: 2 22/ 1 0.9611 5 2/ 1 0.9611 6.0269.T R n R       Fig. 8. Curves of oxide scale stress versus time of superalloy K273. 1648 Hai-tao WANG, Shao-mei ZHENG, and Hua-shun YU t distribution critical value was consulted in mathematical statistics: t0.5(n  2)  3.182. For T  t0.5(n  2), hypothesis H0 was refused, and H1 was obtained. The regression coefficients 3.1015 and 38.8391 of oxide stress equa- tion were significant, and the confidence level reached 95%. In conclusion, the curve of oxide scale stress versus time of test alloy at 800C followed the parabolic law strictly. Early in the nineteen twenties and thirties, the relationship between oxide scale thickness and oxidation time had been studied a lot deeply by Tammann, Wagner et al. In oxidation atmosphere, the oxide scale thickness of metals increased with oxidation time, that for alloys with oxidation resistance, it rigorously followed the parabolic law y2  Kt  C, in which y was oxidation scale thickness, t oxidation time, K and C constants [12—14]. Such typical theory had deeply influenced the oxidation kinetics researches of alloys until now. The parabolic functional relationship of oxide scale stress versus time regressed above shared the same in nature with that of the oxide scale thickness. The coefficient a and b in parabolic law (  a)2  bt were determined synthetically by oxide scale composition, structure and density, oxida- tion temperature, oxygen partial pressure and so on. The function of oxide scale stress played an active role to guide detecting on line for superalloys. The prediction of oxide scale stress by time was beneficial for the monitoring of the exfoliation or ruining of oxide scale and oxi- dation resistance of alloys. At high temperature, oxidation reaction took place on the surface of test alloys. On the basis of the principle of the lowest oxides forming Gibbs free energy, consulting Ellingham figures, the matrix elements Fe, Cr, Mn, Ni were oxidated to be FeO, Cr2O3, MnO and NiO, respec- tively, such were the compositions of the first oxide scale at the begin- ning. On the one hand, with the oxidation reaction going on, the exist- ed oxides grew bigger and bigger, during which the bigger oxides touched and pressed each other, as a result, the oxide scale stress arouse. On the other hand, new oxides came into being constantly at- taching on the former existed oxides, if they grew on the outer surface of the oxide scales, with no concentration and naturally releasing of TABLE 1. Regressing equations of oxide scale stress with time of superalloy K273. Temperature, C Regressing equation Correlation coefficient (R) Regressing time area, h 800 (  3.1015)2  38.8391t 0.9611 1—5 REAL TIME TEST IN SITU OF SUPERALLOY OXIDE SCALE STRESS 1649 growing force, there was no stress accumulated in oxide scales; but if the new oxides grew in the oxide scales, the growing brought squeezing on the matrix or oxide scales, such inner oxides growing was another main source of the oxide scale stress. To sum up, the oxides growing and the inner new oxides forming created stress in oxide scales. When such stress went up over the strength limitation of the oxide scale, meanwhile, the alloy matrix was rigid without any deformation, the scale would bear the full stress to break even exfoliate, speeding up the oxidation reaction, losing the oxidation resistance and matrix protec- tion, which was as far as possible to be avoided for superalloys in use. In this experiment, the test alloys was made to be Archimedes thin slice, which was elastic to be easily bent by stress. Whereupon, being transformed to the deformation of the slice, the oxide scale stress was calculated by the bending displacement. After being oxidated for 5 hours at 800C, the oxide scale morpholo- gy was analysed by SEM. In Figure 9, it was found that the scale struc- ture was complete, compact and continuous, fully covering the matrix. The coarse oxides were the former generated ones as a result of contin- uous growing, during which the oxide scale stress accumulated. Oth- erwise, plenty of small oxide grains attaching on the coarse ones formed later, scattering all over the scales at random, of which the in- ner born ones also made lots of oxide scale stress. Analysed by EDS pat- terns and X-ray Diffraction, as shown in Figs. 10 and 11, the oxide scale composition of test alloys were made up of Cr2O3 and spinel, a kind of composite structure, in which FeO, NiO and MnO did not exist- ed alone, but were polymerized together in spinel (Fe, Ni, Mn)Cr2O4. Such compact highly composited structure endowed the oxide scale high oxidation resistance for superalloys. It was found that the oxide weight gain rate in every oxidation time matched the oxide scale stress increment well. As shown in Figure 12, Fig. 9. SEM morphology of oxide scale of superalloy K273 after 5 hours oxida- tion at 800C. 1650 Hai-tao WANG, Shao-mei ZHENG, and Hua-shun YU less oxide scale stress increment corresponded to lower oxide weight gain rate and better oxidation resistance. Lower oxide weight gain rate meant less or slower oxidation reaction, and fewer new oxide produc- ing. Therefore, there were fewer new oxides to draw or press each other in scales, resulting in smaller oxide scale stress increment. According to formula (26), the oxide scale stress was calculated only by observing the Archimedes curve slice free terminal OC, without de- tecting oxide scale thickness or weighing oxidation weight gain, with- out deriving the relationship of oxide scale thickness or oxidation weight gain versus time. Especially, it was after the oxidation to detect oxide scale thickness or oxidation weight gain of alloys, both of which the real time testing in situ could not be carried out anyway. There- fore, such Archimedes curve slice moment technique formula (26) was terse, clear and convenient, realizing the real time detecting and calcu- lating of oxide scale stress in situ. 4. EXPECTATION The oxide scale stress tested above is a synthetic value, including grow- ing stress in oxides forming and thermal stress during heating or cool- ing. How to distinguish the growing stress and thermal stress is the key problem in the next research work. (1). Testing of oxide scale growing stress. Based on oxide scale stress testing apparatus in Fig. 7, the vacuum system was introduced to test oxide scale growing stress. As shown in Figure 13, the new experiment device were made up of heating system, temperature controlling sys- Fig. 10. EDS patterns of oxide scale of superalloy K273 after 5 hours oxida- tion at 800C. REAL TIME TEST IN SITU OF SUPERALLOY OXIDE SCALE STRESS 1651 tem, vacuum system, reading microscope, vacuum gage, valves, and so on. At first, the slice sample was heated to the given temperature in vacuum condition, then broke vacuum by opening air valve, and let the slice sample be oxidated in air for a certain time, during which the dis- placement of the slice were recorded every moment, and the oxide scale stress was worked out by formula (26). There was no temperature change, oxides formed at the same temperature with no thermal stress, so the stress measured was the pure oxide scale growing stress at given temperature. The bending slice displacement could be read in situ at real time by long focus microscope directly through watching window fixed on the furnace. (2). Testing of oxide scale thermal stress. Oxide scale thermal stress was tested after that for the growing stress. Having been observed the bending displacement for a certain time oxidation at given tempera- ture, the slice sample cooled down to room temperature, during which the slice real time bending displacement was recorded and the scale stress at different temperature was calculated by formula (26). Such stress was the vector sum of the oxide scale growing and thermal stress, subtracting the growing stress calculated above, the leave was the pure thermal stress only by temperature changing. During the pe- Fig. 11. X-ray diffraction of oxide scale of superalloy K273 after 5 hours oxi- dation at 800C. 1652 Hai-tao WANG, Shao-mei ZHENG, and Hua-shun YU riod of cooling, no oxidation reaction occurred without heating, and no oxides formed. Therefore, no new oxide scale growing stress came into being, and the growing stress could be looked as a constant at every temperature, the same as that at the temperature from cooling. Even- tually, the thermal stresses in oxide scale of slice samples in various temperature ranges could be obtained exactly. Such Archimedes curve slice moment technique could observe the slice bending displacement in situ all the time in oxidation. Conse- quently, the oxide scale growing and thermal stresses would be both tested accurately at any temperature for a certain time, which was hard in the former research technologies. 5. CONCLUSIONS 1. A new method of Archimedes curve slice moment was studied to test superalloy oxide scale stress at real time in situ, in which the stress calculating formula was deduced to be: 3 2 2 2 0 0 0 0 0 2 3 ( (OC)/(OC ) 1) , OC OC OC OC 3 (OC) (OC ) 1 log( 1) OC OC OC OC Eh                     in which,  is oxide scale stress, E–slice metal elastic modulus, h– Archimedes curve slice thickness, OC–Archimedes curve slice initial Fig. 12. Oxide scale stress increment and oxidation weight gain rate of super- alloy K273 at 800C in different time. REAL TIME TEST IN SITU OF SUPERALLOY OXIDE SCALE STRESS 1653 polar radius, OC–Archimedes curve slice real time polar radius, 0– Archimedes curve slice initial rotating angle. 2. The curve of oxide scale stress versus time of superalloy K273 fol- lowed the parabolic law (  3.1015)2  38.8391t, strictly oxidated at 800C in 5 hours. 3. The oxides growing and the inner new oxides forming created stress in oxide scales. 4. Having been oxidated for 5 hours at 800C, the oxide scale composi- tion of superalloy K273 was composed by Cr2O3 and spinel (Fe, Ni, Mn)Cr2O4. 5. The oxide scale stress increment matched with the oxide weight gain rate, the less stress increment, the lower oxidation weight gain rate, and the stronger oxidation resistance. This research was financially supported by the Scientific Research Program of Shandong Higher Education of China (No. J14LA09) and the National Natural Science Foundation of China (No. 51307091). REFERENCES 1. H. J. Engell und F. K. Peter, Archiv für das Eisenhüttenwesen, 28: 567 (1957) Fig. 13. Oxide scale stress testing apparatus with vacuum system of Archime- des curve slice sample: 1–reading microscope, 2–watching windows, 3– vacuum furnace, 4–high temperature quartz cover, 5–insulating layer, 6– carbon tube heater, 7–Archimedes curve slice sample, 8–sample fixing sta- tion, 9–cooling water box, 10–cooling water pump, 11–electric motor, 12–vacuum pump, 13–electric motor, 14–convex cavity diffusion pump, 15–high vacuum butterfly bumpers, 16–vacuum pressure gage, 17– platinum rhodium thermocouple, 18–air valve, 19–electrical control cabi- net, 20–transformer. 1654 Hai-tao WANG, Shao-mei ZHENG, and Hua-shun YU (in German). 2. K. Kendall, J. Phys. D: Appl. Phys., 4: 1186 (1971). 3. M. Schutze, Mater. Sci. Technol., 4: 407 (1988). 4. A. M. Huntz, J. L. Lebru, and A. Boumaza, Oxid. Metals, 33: 321 (1990). 5. C. Juricic, H. Pinto, D.Cardinali, M. Klaus, Ch. Genzel, and A. R. Pyzalla, Oxid. Metals, 73: 115 (2010). 6. J. L. Ruan, Y. M. Pei, and D. N. Fang, Acta Mechanica, 223: 2597 (2012). 7. J. Birnie, C. Craggs, D. J. Gardiner, and P. R. Graves, Corrosion Sci., 33: 1 (1992). 8. P. Y. Hou, J. Ager, J. Mougin, and A. Galerie, Oxid. Metals, 75: 229 (2011). 9. F. Yang, X. F. Zhao, and P. Xiao, Oxid. Metals, 81: 331 (2014). 10. Hai-tao Wang, Hua-shun Yu, Yu-qing Wang, Jing Zhang, Zhen-ya Zhang, and Zhi-fu Wang, Metallofiz. Noveishie Tekhnol., 31, No. 5: 701 (2009). 11. Hai-tao Wang, Ji-wen Tan, Chang-song Liu, and Hua-shun Yu, Metallofiz. No- veishie Tekhnol., 33, No. 6: 757 (2011). 12. G. Tammann, Z. Anorg. Chem., 111: 78 (1920). 13. C. Wagner, Z. Physik. Chem., B21: 25 (1933). 14. C. Wagner, Z. Physik. Chem., B32: 447 (1936). << /ASCII85EncodePages false /AllowTransparency false /AutoPositionEPSFiles true /AutoRotatePages /None /Binding /Left /CalGrayProfile (Dot Gain 20%) /CalRGBProfile (sRGB IEC61966-2.1) /CalCMYKProfile (U.S. Web Coated \050SWOP\051 v2) /sRGBProfile (sRGB IEC61966-2.1) /CannotEmbedFontPolicy /Error /CompatibilityLevel 1.4 /CompressObjects /Tags /CompressPages true /ConvertImagesToIndexed true /PassThroughJPEGImages true /CreateJobTicket false /DefaultRenderingIntent /Default /DetectBlends true /DetectCurves 0.0000 /ColorConversionStrategy /CMYK /DoThumbnails false /EmbedAllFonts true /EmbedOpenType false /ParseICCProfilesInComments true /EmbedJobOptions true /DSCReportingLevel 0 /EmitDSCWarnings false /EndPage -1 /ImageMemory 1048576 /LockDistillerParams false /MaxSubsetPct 100 /Optimize true /OPM 1 /ParseDSCComments true /ParseDSCCommentsForDocInfo true /PreserveCopyPage true /PreserveDICMYKValues true /PreserveEPSInfo true /PreserveFlatness true /PreserveHalftoneInfo false /PreserveOPIComments true /PreserveOverprintSettings true /StartPage 1 /SubsetFonts true /TransferFunctionInfo /Apply /UCRandBGInfo /Preserve /UsePrologue false /ColorSettingsFile () /AlwaysEmbed [ true ] /NeverEmbed [ true ] /AntiAliasColorImages false /CropColorImages true /ColorImageMinResolution 300 /ColorImageMinResolutionPolicy /OK /DownsampleColorImages true /ColorImageDownsampleType /Bicubic /ColorImageResolution 300 /ColorImageDepth -1 /ColorImageMinDownsampleDepth 1 /ColorImageDownsampleThreshold 1.50000 /EncodeColorImages true /ColorImageFilter /DCTEncode /AutoFilterColorImages true /ColorImageAutoFilterStrategy /JPEG /ColorACSImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /ColorImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000ColorACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000ColorImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasGrayImages false /CropGrayImages true /GrayImageMinResolution 300 /GrayImageMinResolutionPolicy /OK /DownsampleGrayImages true /GrayImageDownsampleType /Bicubic /GrayImageResolution 300 /GrayImageDepth -1 /GrayImageMinDownsampleDepth 2 /GrayImageDownsampleThreshold 1.50000 /EncodeGrayImages true /GrayImageFilter /DCTEncode /AutoFilterGrayImages true /GrayImageAutoFilterStrategy /JPEG /GrayACSImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /GrayImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000GrayACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000GrayImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasMonoImages false /CropMonoImages true /MonoImageMinResolution 1200 /MonoImageMinResolutionPolicy /OK /DownsampleMonoImages true /MonoImageDownsampleType /Bicubic /MonoImageResolution 1200 /MonoImageDepth -1 /MonoImageDownsampleThreshold 1.50000 /EncodeMonoImages true /MonoImageFilter /CCITTFaxEncode /MonoImageDict << /K -1 >> /AllowPSXObjects false /CheckCompliance [ /None ] /PDFX1aCheck false /PDFX3Check false /PDFXCompliantPDFOnly false /PDFXNoTrimBoxError true /PDFXTrimBoxToMediaBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXSetBleedBoxToMediaBox true /PDFXBleedBoxToTrimBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXOutputIntentProfile () /PDFXOutputConditionIdentifier () /PDFXOutputCondition () /PDFXRegistryName () /PDFXTrapped /False /CreateJDFFile false /Description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> /CHS <FEFF4f7f75288fd94e9b8bbe5b9a521b5efa7684002000410064006f006200650020005000440046002065876863900275284e8e9ad88d2891cf76845370524d53705237300260a853ef4ee54f7f75280020004100630072006f0062006100740020548c002000410064006f00620065002000520065006100640065007200200035002e003000204ee553ca66f49ad87248672c676562535f00521b5efa768400200050004400460020658768633002> /CHT <FEFF4f7f752890194e9b8a2d7f6e5efa7acb7684002000410064006f006200650020005000440046002065874ef69069752865bc9ad854c18cea76845370524d5370523786557406300260a853ef4ee54f7f75280020004100630072006f0062006100740020548c002000410064006f00620065002000520065006100640065007200200035002e003000204ee553ca66f49ad87248672c4f86958b555f5df25efa7acb76840020005000440046002065874ef63002> /CZE <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> /DAN <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> /DEU <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> /ESP <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> /ETI <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> /FRA <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> /GRE <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a stvaranje Adobe PDF dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. Stvoreni PDF dokumenti mogu se otvoriti Acrobat i Adobe Reader 5.0 i kasnijim verzijama.) /HUN <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> /ITA <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> /JPN <FEFF9ad854c18cea306a30d730ea30d730ec30b951fa529b7528002000410064006f0062006500200050004400460020658766f8306e4f5c6210306b4f7f75283057307e305930023053306e8a2d5b9a30674f5c62103055308c305f0020005000440046002030d530a130a430eb306f3001004100630072006f0062006100740020304a30883073002000410064006f00620065002000520065006100640065007200200035002e003000204ee5964d3067958b304f30533068304c3067304d307e305930023053306e8a2d5b9a306b306f30d530a930f330c8306e57cb30818fbc307f304c5fc59808306730593002> /KOR <FEFFc7740020c124c815c7440020c0acc6a9d558c5ec0020ace0d488c9c80020c2dcd5d80020c778c1c4c5d00020ac00c7a50020c801d569d55c002000410064006f0062006500200050004400460020bb38c11cb97c0020c791c131d569b2c8b2e4002e0020c774b807ac8c0020c791c131b41c00200050004400460020bb38c11cb2940020004100630072006f0062006100740020bc0f002000410064006f00620065002000520065006100640065007200200035002e00300020c774c0c1c5d0c11c0020c5f40020c2180020c788c2b5b2c8b2e4002e> /LTH <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> /LVI <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> /NLD (Gebruik deze instellingen om Adobe PDF-documenten te maken die zijn geoptimaliseerd voor prepress-afdrukken van hoge kwaliteit. De gemaakte PDF-documenten kunnen worden geopend met Acrobat en Adobe Reader 5.0 en hoger.) /NOR <FEFF004200720075006b00200064006900730073006500200069006e006e007300740069006c006c0069006e00670065006e0065002000740069006c002000e50020006f0070007000720065007400740065002000410064006f006200650020005000440046002d0064006f006b0075006d0065006e00740065007200200073006f006d00200065007200200062006500730074002000650067006e0065007400200066006f00720020006600f80072007400720079006b006b0073007500740073006b00720069006600740020006100760020006800f800790020006b00760061006c0069007400650074002e0020005000440046002d0064006f006b0075006d0065006e00740065006e00650020006b0061006e002000e50070006e00650073002000690020004100630072006f00620061007400200065006c006c00650072002000410064006f00620065002000520065006100640065007200200035002e003000200065006c006c00650072002000730065006e006500720065002e> /POL <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> /PTB <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> /RUM <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> /RUS <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> /SKY <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> /SLV <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> /SUO <FEFF004b00e40079007400e40020006e00e40069007400e4002000610073006500740075006b007300690061002c0020006b0075006e0020006c0075006f00740020006c00e400680069006e006e00e4002000760061006100740069007600610061006e0020007000610069006e006100740075006b00730065006e002000760061006c006d0069007300740065006c00750074007900f6006800f6006e00200073006f00700069007600690061002000410064006f0062006500200050004400460020002d0064006f006b0075006d0065006e007400740065006a0061002e0020004c0075006f0064007500740020005000440046002d0064006f006b0075006d0065006e00740069007400200076006f0069006400610061006e0020006100760061007400610020004100630072006f0062006100740069006c006c00610020006a0061002000410064006f00620065002000520065006100640065007200200035002e0030003a006c006c00610020006a006100200075007500640065006d006d0069006c006c0061002e> /SVE <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> /TUR <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> /UKR <FEFF04120438043a043e0440043804410442043e043204430439044204350020044604560020043f043004400430043c043504420440043800200434043b044f0020044104420432043e04400435043d043d044f00200434043e043a0443043c0435043d044204560432002000410064006f006200650020005000440046002c0020044f043a04560020043d04300439043a04400430044904350020043f045604340445043e0434044f0442044c00200434043b044f0020043204380441043e043a043e044f043a04560441043d043e0433043e0020043f0435044004350434043404400443043a043e0432043e0433043e0020043404400443043a0443002e00200020042104420432043e04400435043d045600200434043e043a0443043c0435043d0442043800200050004400460020043c043e0436043d04300020043204560434043a0440043804420438002004430020004100630072006f006200610074002004420430002000410064006f00620065002000520065006100640065007200200035002e0030002004300431043e0020043f04560437043d04560448043e04570020043204350440044104560457002e> /ENU (Use these settings to create Adobe PDF documents best suited for high-quality prepress printing. Created PDF documents can be opened with Acrobat and Adobe Reader 5.0 and later.) >> /Namespace [ (Adobe) (Common) (1.0) ] /OtherNamespaces [ << /AsReaderSpreads false /CropImagesToFrames true /ErrorControl /WarnAndContinue /FlattenerIgnoreSpreadOverrides false /IncludeGuidesGrids false /IncludeNonPrinting false /IncludeSlug false /Namespace [ (Adobe) (InDesign) (4.0) ] /OmitPlacedBitmaps false /OmitPlacedEPS false /OmitPlacedPDF false /SimulateOverprint /Legacy >> << /AddBleedMarks false /AddColorBars false /AddCropMarks false /AddPageInfo false /AddRegMarks false /ConvertColors /ConvertToCMYK /DestinationProfileName () /DestinationProfileSelector /DocumentCMYK /Downsample16BitImages true /FlattenerPreset << /PresetSelector /MediumResolution >> /FormElements false /GenerateStructure false /IncludeBookmarks false /IncludeHyperlinks false /IncludeInteractive false /IncludeLayers false /IncludeProfiles false /MultimediaHandling /UseObjectSettings /Namespace [ (Adobe) (CreativeSuite) (2.0) ] /PDFXOutputIntentProfileSelector /DocumentCMYK /PreserveEditing true /UntaggedCMYKHandling /LeaveUntagged /UntaggedRGBHandling /UseDocumentProfile /UseDocumentBleed false >> ] >> setdistillerparams << /HWResolution [2400 2400] /PageSize [612.000 792.000] >> setpagedevice
id nasplib_isofts_kiev_ua-123456789-112644
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
issn 1024-1809
language English
last_indexed 2025-12-07T17:56:02Z
publishDate 2016
publisher Інститут металофізики ім. Г.В. Курдюмова НАН України
record_format dspace
spelling Hai-tao Wang
Shao-mei Zheng
Hua-shun Yu
2017-01-24T21:05:27Z
2017-01-24T21:05:27Z
2016
Real Time Test in situ of Superalloy Oxide Scale Stress by Archimedes Curve Slice Moment Technique / Hai-tao Wang, Shao-mei Zheng, Hua-shun Yu // Металлофизика и новейшие технологии. — 2016. — Т. 38, № 12. — С. 1635-1654. — Бібліогр.: 14 назв. — англ.
1024-1809
DOI: 10.15407/mfint.38.12.1635
PACS: 68.35.Gy, 68.47.Gh, 68.55.J-, 68.55.Nq, 68.60.Dv, 81.65.Kn, 81.65.Mq
https://nasplib.isofts.kiev.ua/handle/123456789/112644
Stress is the direct cause of surface oxide scale exfoliation to ruin the protection for alloy matrix. Therefore, it is the key to study oxide scale mechanical behaviour for discovering the oxidation resistance of alloys. In this paper, a new kind of experimental method ‘Archimedes curve slice moment technique’ is studied to test in situ the real time oxide scale stress of ferro-based superalloy K273 during all the high-temperature oxidation. By the derived formula, the oxide scale stress σ can be calculated precisely only by observing Archimedes curve slice real-time polar radius OC′. Having been oxidated for 5 hours at 800°C, the oxide scale stress versus oxidation time is regressed to follow parabola equation strictly. As the oxides grow and the inner new oxides form in scales to press each other, the oxide scale stress is generated. Analysed by SEM, EDS and XRD, the oxide scale is compact composite structure made up of Cr₂O₃ and spinel (Fe, Ni, Mn)Cr₂O₄. The less oxide scale stress increment brings about the lower oxidation weight gain rate and the better oxidation resistance. Improved by the use of vacuum system, the Archimedes curve slice moment technique is going to test the oxide scale growing and thermal stresses qualitatively and quantitatively in situ all the time at high temperature.
Напруження є безпосередньою причиною відшарування приповерхневої циндри, що призводить до руйнування захисту матриці стопу. Отже, вивчення механічної поведінки циндри є ключем до вивчення стійкости стопів до окиснення. В даній роботі розглянуто нову експериментальну методу міряння скручувального моменту для тонкого шару матеріялу, що був вирізаний за Архімедовою кривою, яка слугує для in situ дослідження в режимі реального часу напружень, що виникають через циндру у суперстопі на основі заліза K273 впродовж усього високотемпературного окиснення. Згідно з одержаним виразом, для точного розрахунку у режимі реального часу напружень σ, що виникають завдяки циндрі, достатньо лише спостереження за полярним радіюсом OC′ зразка, вирізаного за Архімедовою кривою. При дослідженні процесу окиснення протягом 5 годин за температури у 800°C залежність напружень через циндру від часу окиснення було зведено до рівняння параболи. По мірі росту оксиду та формування нових внутрішніх його шарів, які тиснуть один на одного, ґенеруються напруження за рахунок циндри. Аналіза, проведена методами СЕМ, ЕРС та РДА, показала, що циндра ущільнюється у композитну структуру, яка складається з Cr₂O₃ та шпінелі (Fe, Ni, Mn)Cr₂O₄. Зменшення напружень, що виникають за рахунок циндри, приводить до більш низької швидкости окиснення та підвищення стійкости до окиснення. Поліпшену використанням вакуумної системи методику in situ міряння скручувального моменту для зразків, вирізаних за Архімедовою кривою, якісно та кількісно перевірено шляхом дослідження зростання циндри та термічних напружень впродовж усього часу високотемпературного окиснення.
Напряжения являются непосредственной причиной отслоения приповерхностной окалины, что приводит к разрушению защиты матрицы сплава. Следовательно, изучение механического поведения окалины является ключом к выяснению стойкости сплавов к окислению. В данной работе рассматривается новая экспериментальная методика измерения скручивающего момента для тонкого слоя материала, вырезанного по кривой Архимеда, служащая для in situ изучения в режиме реального времени напряжений, возникающих за счёт окалины, в суперсплаве на основе железа K273 в течение всего высокотемпературного окисления. Согласно полученному выражению, для точного расчёта в режиме реального времени напряжений σ, возникающих из-за окалины, достаточно лишь наблюдения за полярным радиусом OC′ образца, вырезанного по кривой Архимеда. При исследовании процесса окисления на протяжении 5 часов при температуре 800°C зависимость напряжений из-за окалины от времени окисления была сведена к уравнению параболы. По мере роста оксида и формирования новых внутренних его слоёв, давящих друг на друга, генерируются напряжения за счёт окалины. Анализ, проведённый методами СЭМ, ЭРС и РДА, показал, что окалина уплотняется в композитную структуру, состоящую из Cr₂O₃ и шпинели (Fe, Ni, Mn)Cr₂O₄. Уменьшение напряжений, возникающих за счёт окалины, приводит к более низкой скорости окисления и повышению стойкости к окислению. Улучшенная использованием вакуумной системы методика in situ измерения скручивающего момента для образцов, вырезанных по кривой Архимеда, качественно и количественно проверена путём исследования роста окалины и термических напряжений на протяжении всего времени высокотемпературного окисления.
This research was financially supported by the Scientific Research Program of Shandong Higher Education of China (No. J14LA09) and the National Natural Science Foundation of China (No. 51307091).
en
Інститут металофізики ім. Г.В. Курдюмова НАН України
Металлофизика и новейшие технологии
Металлические поверхности и плёнки
Real Time Test in situ of Superalloy Oxide Scale Stress by Archimedes Curve Slice Moment Technique
Натурні випробування в реальному часі напружень через циндру у суперстопі методою скручувального моменту для зразка, вирізаного за Архімедовою кривою
Натурные испытания в режиме реального времени напряжений из-за окалины в суперсплаве методом скручивающего момента для образца, вырезанного по кривой Архимеда
Article
published earlier
spellingShingle Real Time Test in situ of Superalloy Oxide Scale Stress by Archimedes Curve Slice Moment Technique
Hai-tao Wang
Shao-mei Zheng
Hua-shun Yu
Металлические поверхности и плёнки
title Real Time Test in situ of Superalloy Oxide Scale Stress by Archimedes Curve Slice Moment Technique
title_alt Натурні випробування в реальному часі напружень через циндру у суперстопі методою скручувального моменту для зразка, вирізаного за Архімедовою кривою
Натурные испытания в режиме реального времени напряжений из-за окалины в суперсплаве методом скручивающего момента для образца, вырезанного по кривой Архимеда
title_full Real Time Test in situ of Superalloy Oxide Scale Stress by Archimedes Curve Slice Moment Technique
title_fullStr Real Time Test in situ of Superalloy Oxide Scale Stress by Archimedes Curve Slice Moment Technique
title_full_unstemmed Real Time Test in situ of Superalloy Oxide Scale Stress by Archimedes Curve Slice Moment Technique
title_short Real Time Test in situ of Superalloy Oxide Scale Stress by Archimedes Curve Slice Moment Technique
title_sort real time test in situ of superalloy oxide scale stress by archimedes curve slice moment technique
topic Металлические поверхности и плёнки
topic_facet Металлические поверхности и плёнки
url https://nasplib.isofts.kiev.ua/handle/123456789/112644
work_keys_str_mv AT haitaowang realtimetestinsituofsuperalloyoxidescalestressbyarchimedescurveslicemomenttechnique
AT shaomeizheng realtimetestinsituofsuperalloyoxidescalestressbyarchimedescurveslicemomenttechnique
AT huashunyu realtimetestinsituofsuperalloyoxidescalestressbyarchimedescurveslicemomenttechnique
AT haitaowang naturníviprobuvannâvrealʹnomučasínapruženʹčerezcindruusuperstopímetodoûskručuvalʹnogomomentudlâzrazkavirízanogozaarhímedovoûkrivoû
AT shaomeizheng naturníviprobuvannâvrealʹnomučasínapruženʹčerezcindruusuperstopímetodoûskručuvalʹnogomomentudlâzrazkavirízanogozaarhímedovoûkrivoû
AT huashunyu naturníviprobuvannâvrealʹnomučasínapruženʹčerezcindruusuperstopímetodoûskručuvalʹnogomomentudlâzrazkavirízanogozaarhímedovoûkrivoû
AT haitaowang naturnyeispytaniâvrežimerealʹnogovremeninaprâženiiizzaokalinyvsupersplavemetodomskručivaûŝegomomentadlâobrazcavyrezannogopokrivoiarhimeda
AT shaomeizheng naturnyeispytaniâvrežimerealʹnogovremeninaprâženiiizzaokalinyvsupersplavemetodomskručivaûŝegomomentadlâobrazcavyrezannogopokrivoiarhimeda
AT huashunyu naturnyeispytaniâvrežimerealʹnogovremeninaprâženiiizzaokalinyvsupersplavemetodomskručivaûŝegomomentadlâobrazcavyrezannogopokrivoiarhimeda