BNi-2真空钎焊0Cr18Ni9不锈钢钎缝组织及相变机理研究

Microstructure Evolution of 0Cr18Ni9 Steel Joint by BNi-2 Vacuum Brazing

采用BNi-2镍基膏状钎料,在1 050℃/10 min工艺条件下,对0Cr18Ni9奥氏体不锈钢进行真空钎焊,并通过光学显微镜、扫描电镜、能谱仪及X射线衍射仪等对钎焊接头界面的显微组织、钎缝内元素分布及物相结构进行测试。结果表明,钎缝区组织由γ-Ni基固溶体和金属化合物Cr_2B等构成。随着钎焊温度升高,钎料中B、Si元素向母材扩散愈充分,在奥氏体界面处沿晶析出Cr_2B等硼化物。

Vacuum brazing of 0Cr18Ni9 steel was carried out at 1 050 ℃ using BNi-2 as the brazing filler alloy.Microstructure,element distribution and phase constitution of the brazed joints were investigated by microscope,scanning electron microscope（SEM） with energy dispersive spectroscopy（EDS） and X-Ray diffraction analysis techniques.The results show that the brazed region consists of Ni solid solution and Cr_2B eutectic,with the increase of temperature,B and Si elements in the brazing seam diffuse sufficiently,Cr_2B boride precipitates in the austenite interface along the grain.