焊粉受潮对等离子弧堆焊层气孔的影响  

Effect of welding powder moisture on porosity of plasma arc surfacing layer

作　　者：刘金湘 陈锐 宋磊 许云飞 孙凡 俞增强 贺彦鹏 LIU Jinxiang;CHEN Rui;SONG Lei;XU Yunfei;SUN Fan;YU Zengqiang;HE Yanpeng(Zhejiang Fuchunjiang Hydropower Equipment Co.,Ltd.,Hangzhou 311504,China)

机构地区：[1]浙江富春江水电设备有限公司,浙江杭州311504

出　　处：《电焊机》2020年第5期124-127,I0011,共5页Electric Welding Machine

摘　　要：某先进堆型高温液态金属泵的静压轴承内壁需大面积堆焊司太立合金,由于司太立合金硬度高、韧性差,堆焊过程中预热温度高,熔池冷却速度慢,且连续堆焊时间长,堆焊层易出现裂纹、未熔合、气孔等问题。针对堆焊层内部出现的气孔,逐一排查可能原因,确定主要原因是焊粉受潮。对焊粉进行烘干试验和烘干前后的堆焊试验,再现了焊接缺陷,由此规定焊粉使用前必须进行250℃×2 h的烘干处理,避免气孔产生。The inner wall of static bearing of an advanced high temperature liquid metal pump needs to be surfacing with large area of stellite alloy. Due to the high hardness and poor toughness of the stellite alloy,the preheating temperature is high,the cooling speed of molten pool is slow,and the continuous welding time is long. Therefore,the final surfacing layer is prone to crack,incomplete fusion,porosity and other problems. According to the existing pores in the surfacing layer,the possible causes were investigated one by one,and the main reason is finally determined to be moisture. According to the powder drying test and surfacing test before and after drying,the welding defects were reappeared. It is stipulated that the welding powder must be dried at 250 ℃×2 h before surfacing to avoid the porosities.

关 键 词：司太立合金 等离子弧堆焊 气孔 焊粉受潮 

分 类 号：TG445[金属学及工艺—焊接]