Contributions of carbon content and cooling rate on phase transformations and mechanical properties of sintered Fe-1.5Cr-0.2Mo-xC alloys

Abstract

Microstructural development in sintered Fe-1.5Cr-0.2Mo-xC alloys, produced under different cooling rates of 0.1°C·s-1 and 5.4°C·s-1, was investigated. It was found that, in slowly sintered Fe-1.5Cr-0.2Mo-xC alloys, the microstructure changed from hypoeutectoid to eutectoid and to hypereutectoid steel microstructural features with increasing carbon content. Under the fast-cooling rate of 5.4°C·s-1, the microstructural change with respect to the increase of carbon content involved the competition between the formation of ferrite + carbide mixture and that of martensite-austenite constituent. The increase of tensile strength of slowly cooled sintered Fe-1.5Cr-0.2Mo-xC alloys with increasing carbon content was attributed to the increase of pearlite fraction, while the increase of tensile strength of fast-cooled sintered Fe-1.5Cr-0.2Mo-xC alloys was attributed to ferrite morphology change, the formation of ferrite + carbide mixture, and the formation of martensite-austenite constituent. © 2026, Chulalognkorn University. All Right Reserved.