摘要
采用BNi-2镍基钎料对0Cr18Ni9奥氏体不锈钢在1050℃条件下进行真空钎焊,通过扫描电镜、X射线衍射仪和纳米压痕仪等对钎焊接头显微组织、元素分布、物相结构及纳米硬度和弹性模量进行测试。结果表明:钎缝组织由Ni基固溶体和Cr2B等化合物构成。降熔B元素在扩散区和钎缝界面处形成Cr2B层,并沿奥氏体晶界进行扩散,扩散层厚度为30μm。采用纳米压入方法得到压入深度与时间的关系曲线,并根据lnε和lnσ之间线形关系求解应力敏感指数,钎缝内镍基固溶体及析出相应力敏感指数分别为4.95和3.25。
0Cr18Ni9 stainless steel was vacuum brazed using BNi-2 amorphous filler alloy at 1050 ℃. The microstructure and composition, as well as the elastic modulus and nanohardness of joints were detected by using SEM, EDS, XRD and nanoindenter. The results show that the typical microstructure of brazed joint are consisted of Ni-based solid solution and Cr2B intermetallic compound. The layer of Cr2B intermetallic compound is formed at the interface of the brazed joint and diffusion layer. The Boron atoms diffuse along the grain boundary of austenite and the thickness of diffusion layer keeps approximately 30μm. The curves of creep displacement and holding time are analyzed by nanoindentation test, and the creep stress exponents at room temperature are obtained by in ε-lnσ fitting method. The creep stress exponents of Ni-based solid solution and precipitates are 4.95 and 3.25, respectively.
出处
《金属热处理》
CAS
CSCD
北大核心
2017年第1期104-108,共5页
Heat Treatment of Metals
基金
江苏省大型工程装备检测与控制重点建设实验室开放课题(JSKLEDC201412)
