异种钢材的超塑性扩散连接工艺研究

探讨了利用微细晶超塑性实现Ｗ６Ｍｏ５Ｃｒ４Ｖ２钢和４５钢的扩散连接的可行性及影响因素。通过电镜分析以及界面处显微硬度等的测试，对超塑性连接接头及其界面组织和显微硬度的变化进行了观察与分析。实验表明：超细化处理后的Ｗ６Ｍｏ５Ｃｒ４Ｖ２钢在超塑性变形温度及应变速率范围内经短时间超塑性压接即可实现接头性能达到与母材（４５钢）相同的扩散连接接头。

Study on Superplastic Diffusion Bonding of Different Steels

Aiming at improving the quality of welding joints of high speed steel and carbon steel, we carried out experiments to study the feasibility of structural superplastic diffusion bonding of W6Mo5Cr4V2 with 45 steel, and the main factors which influence the bonding. Microstructure, strength of welded joint and change of microhardness have been observed and analyzed by means of SEM (scanning electron microscope) and microhardness test. Figs.1 through 3 show the influence of temperature, pre stressing, and welding time on the strength of the joint. Fig.4 shows the microhardness of the joint between W6Mo5Cr4V2 and 45 steel. Fig.5 shows the microstructure of the joint. They show that after fine graining treatment and short time superplastic pressing formation under the conditions of superplastic temperature, pre pressing and strain rate, W6Mo5Cr4V2/45 specimens can achieve solid state diffusion bonding, and the property of welded area is the same as the parent material (i.e. 45 steel) in the specimen.