MHC合金粉末冶金制备及其锻造棒材力学性能研究

针对MHC合金粉末的冶金制备工艺及其烧结坯性能、锻造态和经热处理后的MHC合金棒组织与力学性能开展研究。结果表明:所研究的粉末冶金工艺参数可制备出适宜于锻造加工的MHC烧结棒坯;相比于烧结坯,经88.6%锻造比锻造后MHC合金棒材的硬度、强度显著提高;经88.6%锻造比锻造后的MHC合金棒材的完全再结晶温度高于1500℃,经1200℃保温1 h热处理后,MHC合金棒材的室温强度Rp 0.2>770 MPa,硬度达到HRA 66.5;真空气氛下800℃高温拉伸强度Rp 0.2>450 MPa,延伸率大于18.5%。表明本研究制备的MHC合金棒材具备显著的室温高强高硬特性和良好的高温综合力学性能。

Preparation of MHC Alloy by Powder Metallurgy and Mechanical Properties of Its Forged Bar

The powder metallurgy process of MHC alloy,the properties of sintered MHC alloy billets,the mechanical properties and microstructure of forged and heat treatmented MHC alloy bars were studied in this paper.The results showed that the sintered MHC alloy billets produced by powder metallurgy which was proposed in this paper can meet forging requirements.The hardness and strength of MHC alloy billets with 88.6%forged ratio were obvious higher than those of sintered billets.The heat treatment experiments showed that the full recrystallization temperature of MHC alloy billets with 88.6%forged ratio were higher than 1500℃。The room temperature strength(Rp 0.2)of MHC alloy bars which were heat treatmented after 1200℃×1h was higher than 770 MPa,and the hardness reached HRA66.5,that showed obvious high strength and high hardness performance.The 800℃strength(Rp 0.2)of MHC alloy was 450 MPa and elongation was 18.5%that showed the MHC alloy bars produced by parameters of this paper had excellent high mechanical properties.