论文部分内容阅读
使用质量比为 6:4 的混合镍基钎料 BNi-2 与 BNi-5 对 316L 不锈钢进行真空钎焊。由于钎缝间隙对钎焊接头组织性能有重要影响,所以在钎焊温度 1140 ℃,保温时间 10 min 的钎焊参数下,分别对钎缝间隙为 30,60 和 100 μm进行了钎焊实验。主要通过光学显微镜、扫描电子显微镜、能谱分析仪、电子探针显微分析仪以及显微硬度计等对钎焊接头界面组织特征进行分析。结果表明,分布于钎焊接头中心连续共晶组织是导致裂纹扩展的主要通道。另外,研究发现当进行完整的等温凝固过程时,只有γ-Ni 固溶体相存在于钎焊接头中,但在钎缝与母材边界的沿晶界区域仍存在第二相的金属间化合物。
316L stainless steel was vacuum brazed using a mixed Ni-based brazing filler metal BNi-2 and BNi-5 in a mass ratio of 6: 4. Due to the influence of brazing gap on the microstructure and properties of brazed joints, brazing experiments were carried out on brazing seam clearances of 30, 60 and 100 μm respectively at brazing parameters of brazing temperature 1140 ℃ and holding time 10 min. Mainly through the optical microscope, scanning electron microscopy, energy spectrum analyzer, electron probe microanalysis and microhardness analysis of the interface characteristics of brazed joints. The results show that the continuous eutectic microstructure distributed in the center of the brazed joint is the main channel leading to the crack propagation. In addition, it was found that when the complete isothermal solidification process, only the γ-Ni solid solution phase exists in the brazed joint, but the intermetallic compound of the second phase still exists in the grain boundary region along the boundary between the brazing seam and the base metal.