The Effect of Cooling Rate on the Structure and Mechanical Properties of Fe-3%Mn-(Cr)-(Mo)-C PM Steels
The effect of different cooling rate after sintering Mn steels at 1120°C and 1250°C by adding Cr and Mo was investigated. Pre-alloyed Astaloy CrM and CrL, ferromanganese and graphite powders were used as the starting powders. Pressing was carried out in steel rigid dies to achieve the same density in the range of 6.8-7.2 g/cm3. During pressing rectangular and ISO 2740 specimens were prepared. Then, green compacts were sintered at 1120°C and 1250°C for 60 minutes in atmosphere with different H2/N2 content and cooled at a cooling rate 1.4°C/min (slow, furnace cooling) and 65°C/min (convective cooling). Convecitve cooled specimens were subsequently tempered at 200°C for 60 and 240 minutes. To investigate the mechanical properties: UTS, elongation A, R0.2 yield offset, TRS, impact toughness IT and hardness measurements results were examined. After the mechanical examination, the microstructure of Fe-Mn-Cr-Mo-C PM steels were studied by optical microscopy.
Duk Yong Yoon, Suk-Joong L. Kang, Kwang Yong Eun and Yong-Seog Kim
M. Sulowski et al., "The Effect of Cooling Rate on the Structure and Mechanical Properties of Fe-3%Mn-(Cr)-(Mo)-C PM Steels", Materials Science Forum, Vols. 534-536, pp. 757-760, 2007