一种高性能Fe—Cr—Mo粉末冶金钢的研究

Research on High Performance Fe--Cr--Mo Powder Metallurgy Steel

在Fe—0．5Mo预合金粉末（LAP100．29A4）中添加不同含量的铬铁合金粉末，于1200℃烧结，采用烧结硬化工艺制备一种Fe-Cr-Mo粉末冶金钢，研究铬铁合金粉末添加量对材料的密度、硬度、强度和显微组织的影响。结果表明：添加铬铁合金粉末获得的Fe—Cr—M0粉末冶金钢具有较高密度；随铬铁合金粉末含量的增加，Fe—Cr—Mo粉末冶金钢的硬度升高，最高值达到HRC46；Fe-Cr-Mo粉末冶金钢的强度随着铬铁合金粉末含量的增加，总体上呈现出先上升后下降的趋势，抗拉强度最高值达到了839MPa，屈服强度达到820MPa；合金组织中以马氏体相变为主，从而可获得高强度、高硬度的Fe—Cr—Mo粉末冶金钢。

The sinter hardenable materials named Fe--Cr--Mo steel have been obtained from the mixed powder of Cr--Fe alloyed powder and Fe--0.5Mo alloy powder （LAP 100. 29 A4） via sinter hardening at 1200℃, which the added Cr--Fe al- loy powder content is different. The effects with different Cr--Fe content on density, hardness and mechanical properties of the sintered materials have been investigated. The results indicate that the high sintered density of iron--base PM materials, which were made of the Fe--Mo pre--alloyed powder with a small amount of Cr--Fe alloy powder, could been obtained; the hardness with a maximum value HRCA6 increased with the Cr--Fe alloy powder content increasing; the tensile strength in- creased as the Cr-- Fe alloy powder content increasing and then reduced, and the highest tensile strength reached 839MPa while the yield strength was 820MPa. The microstructure of the sintered specimens was mainly composed of martensite, as a result of martensitic transformation, which leaded to higher strength and higher hardness for the obtained Fe--Cr--Mo PM steel.