Prediction of mechanical properties of Fe–Cr–Mo sintered steel in relationship with microstructure

Highlights: ► Thermodynamic conditions for proper sintering of alloyed sintered steel. ► Prediction of tensile and yield strength of pre-alloyed sintered steel. ► Effect of sintering conditions on mechanical properties of sintered steel. ► Accurate prediction of mechanical properties for bainitic microstructure. ► Lower accuracy of properties prediction for ferritic–pearlitic microstructures. -- Abstract: The contribution deals with the evaluation of required thermodynamic conditions for proper sintering and prediction of tensile and yield strength of Cr–Mo-pre-alloyed sintered steel. The material used in experiment was Fe–1.5 Cr–0.2 Mo pre-alloyed water atomised steel powder with addition 0.3–0.7% of graphite. Three different sintering routes were used applying sintering at 1180 and 1250 °C for 40 and 60 min in 10%H2 + 90%N2 atmosphere of different purity. The influence of sintering conditions on the microstructure and mechanical properties of sintered Fe–1.5Cr–0.2Mo–(0.3–0.7)C steels is analyzed and mechanical properties are predicted. Results indicate that very accurate prediction of mechanical properties can be achieved for sintered steel with bainitic microstructure (higher carbon content) and higher differences were obtained for ferritic–pearlitic microstructures. High sensitivity of mechanical properties on sintering atmosphere purity for chromium prealloyed powder steel was identified. Required sintering atmosphere composition and purity for successful sintering of studied material were evaluated.