Вивчення структурно-фазового стану та механічних властивостей високопластичних надміцних сталей Fe-Mn-Al-C. Повідомлення 2

• Date: 2023
• Main Authors: Верзілов, О. П., Семенко, А. Ю., Ворон, М. М., Шемет, В. Ж.
• Format: Article
• Language: Ukrainian
• Published: Physico-technological Institute of Metals and Alloys 2023
• Subjects: Fe-Mn-Al-C; структура; фазовий склад; хімічний склад; неметалеві включення
• Online Access: https://www.metalsandcasting.com/index.php/mcu/article/view/86
• Journal Title: Metal and Casting of Ukraine

The article considers the thermodynamics of phase formation in equilibrium conditions in high-strength steels of the new generation Fe-20Mn-xAl-1C (x = 5–12 wt.%) and technological features of obtaining experimental samples of these steels. The analysis of their chemical composition, structure and features of phase composition and the presence of non-metallic inclusions in them is carried out. A preliminary estimate of the formation of crystalline phases in the Quaternary Fe-Mn-Al-C system was performed using calculation programs. According to the calculations the FCC phase (austenite) begins to stand out in the melt at a temperature of 1400 °C. Cementite, carbides and ferrite are released at lower temperatures. The molar fraction of these phases significantly depends on the concentration of manganese. Calculations of phase equilibria correlate well with the literature data. That is, for alloys containing more than 20 wt.% manganese at a concentration of aluminum 4–5 wt.% and carbon up to 1 wt.% is characterized by the reaction of primary crystallization of austenite (FCC): L → g. During the research, samples of experimental alloys were obtained. Analyzing the mechanical properties of the samples, it can be seen that to obtain in the cast state alloys with a minimum level of mechanical and technological properties, it is necessary to prevent both high content of aluminum and carbon with a manganese content of about 20 wt.%. When increasing the manganese content to 24–25 wt.%, the greatest strength and ductility are provided at an aluminum and carbon content of about 10 wt.% and 1 wt.% in accordance. The observed trends indicate a significant influence of elements, the content of which depends on the formation of к-carbides. However, in addition to their obvious presence, the size, morphology and distribution of all structural-phase components of alloys are also important factors influencing the mechanical properties of alloys. For this reason, a preliminary assessment of the structure of the experimental samples was performed.