Прогнозування розчинення карбідів цементитного типу в заевтектоїдних сталях
Analysis of the literature review shows that the dissolution time of carbides, during the transformation of pearlite into austenite, in carbon eutectoid steel, in the temperature range from 760 to 880 °C, is in 50-1000 times less than in hypereutectoid steels, which is associated with an increase ca...
Gespeichert in:
| Datum: | 2025 |
|---|---|
| 1. Verfasser: | |
| Format: | Artikel |
| Sprache: | Ukrainian |
| Veröffentlicht: |
Physico- Technological Institute of Metals and Alloys of the NAS of Ukraine
2025
|
| Schlagworte: | |
| Online Zugang: | https://momjournal.org.ua/index.php/mom/article/view/2025-1-2 |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| Назва журналу: | Metal Science and Treatment of Metals |
Institution
Metal Science and Treatment of Metals| Zusammenfassung: | Analysis of the literature review shows that the dissolution time of carbides, during the transformation of pearlite into austenite, in carbon eutectoid steel, in the temperature range from 760 to 880 °C, is in 50-1000 times less than in hypereutectoid steels, which is associated with an increase carbon diffusion distances to reach an equilibrium state.
To date, there is no information about mathematical models that describe the kinetics of dissolution in carbides of hypereutectoid steels depending on the rate of carbon diffusion and austenite grain size.
The aim of the work is to study the regularity of carbide dissolution in austenite of hypereutectoid steels during heating and to develop a mathematical model of their dissolution kinetics.
The quantitative dependence of the austenite grain size of hypereutectoid steels of the carbon, chromium, silicon content and the heating temperature was established, and it was shown that the most significant effect of about 45% is exerted by temperature. The influence of chromium is 25%, carbon – 17%, and silicon – 13%.
A model of the influence of carbon, chromium and temperature on the diffusion coefficient of carbon in austenite in the temperature range from 1000 to 1200 oС, with a steel content of 0.92 to 1.83% carbon and 1.06 to 2.66% chromium, was developed, which with a probability of 95%, a correlation coefficient of 0.998 and an average approximation error of 0.21% describes the diffusion process.
As a result of the research, it was established that the dissolution of carbides in austenite of hypereutectoid steels during heating is determined by the rate of carbon diffusion, austenite grain sizes, time and temperature of the process.
A mathematical model of the kinetics of dissolution of carbides in austenite of hypereutectoid steels during heating was developed, taking into account the influence of the chemical composition and temperature of the steel on the diffusion mobility of carbon and the size of the austenite grain. A comparison of the calculated and experimental values of the dissolution time of cementite-type carbides in austenite shows that there is a close correlation between them, with a probability of 95%, a correlation coefficient of 0.974 and a error of 4.5%.
The materials of the article can be used by scientists for further research and practitioners in the selection of materials for making tools. |
|---|