采用BNi7镍基钎料真空钎焊316L不锈钢, 通过光学显微镜、扫描电镜及其附带的能谱仪、显微硬度计研究了钎焊间隙和保温时间对钎焊接头钎缝显微组织、元素分布及显微硬度的影响。结果表明: 316L不锈钢接头钎缝钎缝主要由镍-铁基固溶体和金属间化合物组成; 金属间化合物含量随钎焊间隙的增大而减少, 随钎焊保温时间的延长而降低, 当两者分别达到40 μm和60 min时, 钎缝金属间化合物含量最少, 显微硬度分布较为均匀。

Vacuum brazing of 316L stainless steel with BNi7 Ni-based filler metal was carried out. The influences of brazing clearance and holding time on microstructure, element distribution and microhardness of the joint seam were studied by optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and microhardness test. The results show that the joint seam was comprised of Ni-Fe based solid solution and intermetallic compounds. The content of intermetallic compounds decreased with the increase of brazing clearance, and decreased with the prolongment of brazing holding time. When the brazing clearance and holding time were 40 μm and 60 min respectively, the content of intermetallic compounds was the least and the hardness distribution was more uniform.