Correlation of 12% Chromium Ferritic-Martensitic Steel Heat Resistance with Supercooled Austenite Stability Indices

Resumo

Development of new heat-resistant ferritic-martensitic steels with 12% chromium designed for operation at 700–720 °С is a complex multifactorial task. The main characteristics of such steels that define the possibility of their application at elevated temperature are high values of strength within the temperature range of 20–720 °С, and high values of creep resistance at temperatures of 650 °C and above with a satisfactory ductility level (at least 6–12% at 20–720 °С). A significant amount of time is required in the case of large range of steels investigated to determine the abovementioned properties. An important task is finding readily and quickly obtained properties by which it is possible to estimate the level of steel heat resistance properties. Diagrams for isothermal decomposition of supercooled austenite are analyzed and equations are found in the present work for their connection with yield strength and creep strength of the materials studied.