MIM Fe-Ni-Cr低合金钢的性能和组织

研究了以Fe-2Ni为基体，向其中分别加入0．5％、1％和3％的Cr时，合金烧结态和热处理态的力学性能和微观组织变化。结果表明，随着Cr含量的增加，合金密度降低，孔隙增多且变大；烧结态强度和硬度增加，伸长率和冲击吸收功下降。Fe-2Ni-3Cr合金的强度和硬度最高分别为975MPa和73．3HRB；Fe-2Ni合金的伸长率和冲击吸收功最高分别为12％和7．6J；热处理态合金强度相差不大，Fe-2Ni-0．5Cr的强度最高达到1240MPa；伸长率和冲击功下降；硬度增加。烧结态合金的微观组织为珠光体＋很少量的铁素体，Fe-2Ni-3Cr合金中出现Ni的富集区；热处理态合金的微观组织加入Cr后变为回火马氏体，且在Fe-2Ni-3Cr合金中出现网状的二次渗碳体。

Properties and microstructure of MIM Fe-Ni-Cr low alloy steel

The present study is concerned with the properties and microstructure of sintered and heat treated Fe-2Ni alloys with Cr addive of 0.5%,1% and 3%.The results show that with Cr increasing,the density of alloy reduces,number and size of pore increase;the strength and the hardness of sintered Fe-Ni-Cr alloy increase,the elongation and the impact energy of sintered Fe-Ni-Cr alloy reduce.The strength and the hardness of Fe-2Ni-3Cr alloy are 975 MPa and 73.3 HRB respectively;the elongation and the impact energy of Fe-2Ni are 12% and 7.6 J;The strength of alloy change slightly after heat treatment,the max is 1 240 MPa for Fe-2Ni-0.5Cr alloy;the elongation and the impact energy of sintered Fe-Ni-Cr alloy reduce and the hardness increase after heat treatment.The microstructure of sintered alloy consists of pearlite and little ferrite,the enrichment area of Ni occurs in the microstructure of Fe-2Ni-3Cr alloy;the microstructure of heat treated alloy with Cr additve consists of temper martensite and meshy secondary cementite.