铬对FeNiMoCu系预合金粉末烧结性能的影响

将Cr以铬铁的形式加入到FeNiMoCu系预合金粉末中,经充分混合后单轴600MPa下压制,然后分别采用冷压烧结、烧结热锻和复烧工艺,研究铬对FeNiMoCu系预合金粉末烧结密度、组织及性能的影响.实验结果表明,添加到预合金粉末中的铬在1573K温度烧结时可均匀扩散到组织中,使组织性能得到改善;随添加的铬量和复烧温度的提高,微观组织硬度和表观硬度逐渐增加,经热锻及热锻复烧可获得较高的烧结密度和硬度.当复烧温度为1573K时,Fe-1.5Cr-2.0Ni-0.85Mo-1.7Cu-0.5C获得的密度为7.71 g/cm3,硬度为105HRB;Fe-4.0Cr-3.0Ni-0.85Mo-1.7Cu-0.5C获得的密度为7.63g/cm3,硬度为105HRB.

Effects of chromium on sintering properties of FeNiMoCu prealloyed powders

The chromium in the form of Cr-Fe powders was added to the FeNiMoCu prealloyed powder,the powder mixture was uniaxially pressed at 600MPa to green samples,and then the samples were sintered,sintered and hot-forged,and re-sintered,respectively.Influence of chromium addition on the density,microstructure and properties of the FeNiMoCu prealloyed powders were studied.Results show that chromium element added to the prealloyed powders is homogenously diffused into structure and improves microstructure after sintering at 1573K.Microhardness and apparent hardness increase with increasing amount of chromium addition and re-sintering temperature,and higher density and hardness can be obtained after hot-forging sintering and re-sintering.When the samples are re-sintered at 1573K,density value of 7.71 g/cm~3 and hardness value of 105HRB are obtained for Fe-1.5Cr-2.0Ni-0.85Mo-1.7Cu-0.5C alloy,and density value of 7.63g/cm~3 and hardness value of 105HRB are obtained for Fe-4.0Cr-3.0Ni-0.85Mo-1.7Cu-0.5C alloy.