保温时间对 K452高温合金钎焊接头组织与性能的影响

摘要

Vacuum brazing of K452 superalloy was performed with cobalt-base filler metal and nickel-base superalloy powder under bra-zing conditions of 1 170℃ /10min,1 170℃ /60min and 1 170℃ /120min respectively.The microstructure of brazed joints was analyzed by using SEM and EDS,and the high-temperature mechanical properties were also studied.The results show that the sound joints with fine microstructure and rare pores are achieved under 1 170℃ /60min brazing procedure,due to the good quality of interface.The joints braze under 1 170℃ /120min show the highest mechanical properties because of better interface quality,the average 900℃ tensile strength of 400MPa and 900℃ /100MPa stress-rupture life of 141 h /55min.But there morepoles are presented,and many white parti-cles of compound congregated and grow up between the nickel-base superalloy powder in the brazing seam.%采用钴基钎料及镍基合金粉料，分别在1170℃保温10min、60min 和120min 的钎焊工艺下，对 K452镍基铸造高温合金进行真空钎焊实验，通过扫描电镜和能谱分析仪进行了接头显微组织观察与物相分析，并测试钎焊接头的高温力学性能。结果表明：在保温60min 的工艺规范下，界面实现较好的结合，钎缝内部孔洞缺陷较少，钎缝组织均匀，有利于钎焊接头性能的提高；在更长的保温时间120min 下，钎缝内部又有蚀孔缺陷形成，且较多的白色块状化合物在合金粉颗粒间聚集长大，但界面结合良好，钎焊接头性能较高，900℃抗拉强度达到400MPa，900℃／100MPa 持久寿命为141 h55min。