气门密封面两种熔焊工艺焊层的组织、性能比较  

Comparison of Two Fusion Welding Techniques for Valve Surface Sealing

作　　者：张富邦[1] 胡春莲[1] 侯尚林[2] 陈生圣[1] 

机构地区：[1]兰州理工大学合金粉末厂,甘肃兰州730050 [2]兰州理工大学理学院,甘肃兰州730050

出　　处：《材料保护》2005年第8期59-60,66,共3页Materials Protection

摘　　要：对真空高频熔焊和等离子堆焊两种工艺下成型的汽车发动机Co-Cr-W合金气门密封面焊层进行分析比较。结果表明:二种堆焊工艺合金焊层都与基体形成良好冶金结合,等离子堆焊的细小树枝晶组织比真空高频感应焊层等轴晶组织细密;550℃下在RFT-Ⅲ型高温磨损试验机上等离子焊层耐磨性优于真空高频感应焊层;在10%HNO3水溶液20h腐蚀试验中,等离子焊层的耐腐性能比高频感应焊层好。等离子堆焊比真空高频熔焊更适合汽车发动机气门密封面表面处理。Vacuum high-frequency fusion welding and plasma overlay welding techniques were used to prepare Co-Cr-W coatings for valve surface sealing in an automobile engine. The structures and wear- and corrosion-resistance of the Co-Cr-W coatings prepared using the two techniques were comparatively investigated. It was found that excellent joints were formed between the matrix and the coatings prepared. The coating made by plasma overlay welding technique had slim tree dendrite microstructure more compact than the equiaxial crystal microstructure of the coating made by vacuum high-frequency fusion welding technique. Moreover, the plasma overlay welding technique is more suitable to the valve surface sealing of the automobile engine than the vacuum high-frequency fusion welding technique. This was because the coating made by the plasma overlay welding had much better wear- and corrosion-resistance than that made by vacuum high-frequency fusion welding, as tested on RFT high temperature friction and wear tester at 550 ℃ and in 10%HNO_3 solution for 20 h.

关 键 词：熔焊工艺 组织 耐磨性 耐腐蚀性 

分 类 号：TG44[金属学及工艺—焊接]