304L不锈钢真空钎焊接头晶间腐蚀性能试验研究  

Experimental Study on Intergranular Corrosion Resistance of 304L Stainless Steel Vacuum Brazed Joints

作　　者：袁野 周希 李莎 YUAN Ye;ZHOU Xi;LI Sha(CNNC Jianzhong Nuclear Fuel Co.,Ltd.,Yibin 644000,China)

机构地区：[1]中核建中核燃料元件有限公司,四川宜宾644000

出　　处：《热加工工艺》2021年第11期63-66,共4页Hot Working Technology

摘　　要：采用硫酸-硫酸铜法对核级304L不锈钢和BNi-7钎焊料真空钎焊的钎焊接头试样进行晶间腐蚀试验,并使用金相显微镜和扫描电镜对接头组织进行观察和成分分析。结果表明,不锈钢钎焊接头存在镍基固溶体的选择性腐蚀,镍基固溶体的晶间腐蚀以及母材扩散区的晶间腐蚀三种腐蚀现象,主要原因是钎缝接头内形成的化合物相和Cr优先结合导致周围区域固溶体的贫Cr,从而在钎缝中不同区域表现出不同的电化学行为,在特定的电解质介质环境产生局部腐蚀。The H2SO4-CuSO4 method was used to perform intergranular corrosion tests on the brazed joints of nuclear grade 304L stainless steel and BNi-7 filler metal by vacuum brazing. The metalloscope and SEM were used to observe the microstructure and perform the composition analysis. The results show that three kinds of corrosion phenomenon existed in the brazed joints, including selective corrosion of nickel base solid solution, intergranular corrosion of nickelbase solid solution, and intergranular corrosion of base metal diffusion zone, respectively. The main reason is lack of Cr in the surrounding area of the compound phase due to the preferential combination of the compound phase and Cr in the brazed joint. Thus, different electrochemical behavior is shown in different areas in the brazing seam, and local corrosion occurs in the specific conductive medium environment.

关 键 词：不锈钢 真空钎焊 晶间腐蚀 选择性腐蚀 

分 类 号：TG454[金属学及工艺—焊接] TG174.33