铜粉添加量对不锈钢钎焊接头组织和显微硬度的影响

Effects of Cu Powders Contents on Microstructure and Micro-hardness of Stainless Steel Brazed Joint

在BNi-7镍基钎料中添加纯铜粉制成组合钎料,然后采用真空方法在板间隙为40μm的条件下钎焊316L不锈钢,研究了铜粉含量对钎焊接头组织和显微硬度的影响。结果表明:在BNi-7钎料中添加纯铜粉能有效改善较大间隙接头的填充性能;添加纯铜粉后,钎缝中的脆性化合物显著减少,并呈岛状、条状、麻点状等镶嵌在镍基固溶体中,导致接头的显微硬度降低,当添加纯铜粉的质量分数为9%时,钎缝中的脆性化合物最少,接头的显微硬度为1 000 MPa。

The composite fillers were composed of BNi-7filler and pure Cu powders,and then them was used to braze 316 Lstainless steels with clearance of 40 μm.The effects of different pure Cu powder contents on microstructure and micro-hardness of brazed joints were studied.The results show that adding Cu powders into BNi-7filler can improve the filling capability of brazed joint with large clearance effectively.Because of the addition of pure Cu powders,the brittle compounds in the brazing seam reduce significantly,and they are inlaid into the nickel based solid solution with the shapes of island,strip and point.All of these decrease the micro-hardness of brazed joints.The least brittle compounds were found in the brazed joint with pure Cu powders content of 9wt%,and the micro-hardness of the joint was 1 000 MPa.