钎焊温度对YG8硬质合金与1Cr18Ni9Ti不锈钢钎焊接头组织与力学性能的影响

摘要

Using L304 silver solder as brazing filler metal,YG8 cemented carbide and 1Cr18Ni9Ti stainless steel were welded by high temperature argon gas-shielding brazing.The effects of brazing temperature on microstructure and mechanical properties of the brazing joint were studied by microstructure observation,energy spectrum analysis,hardness test and room-temperature shear test.The results show that with the increase of brazing temperature,the microstructure of joint was getting more and more uniform and compact.The brazing filler metal was melted gradually and filled the weld seam fully,and the brazing quality was improved.However,when the brazing temperature was higher than 920 ℃,the brazing joint exhibited overheating phenomenon,the microstructure became coarse and the brazing quality became poor.With the increase of brazing temperature,the shear strength and micro-hardness of brazing joint increased first and then decreased.When the brazing temperature was 910 ℃,the shear strength of brazing joint was 147.5 MPa and the micro-hardness was 194 HV,indicating that the brazing joint had the best comprehensive mechanical properties.%以L304银焊片为钎料,对 YG8硬质合金与1Cr18Ni9Ti 不锈钢进行高温氩气保护钎焊,通过显微组织观察、能谱分析、硬度测试、室温剪切试验等,研究了钎焊温度对钎焊接头组织及力学性能的影响.结果表明:随着钎焊温度的升高,接头焊缝的组织更加均匀致密,钎料逐渐熔化且充分填充焊缝,钎焊质量变好,但当钎焊温度高于920 ℃时,钎焊接头出现过热现象,组织粗大,钎焊质量变差;随着钎焊温度的升高,钎焊接头的剪切强度和显微硬度均呈先增大后减小的趋势;当钎焊温度为910 ℃时,钎焊接头的剪切强度为147.5 MPa,显微硬度为194 HV,钎焊接头的综合力学性能最好.