氧乙炔堆焊钩爪的耐腐蚀性能研究  

Research of Corrosion Resistance of Oxyacetylene Welded Latch Arm

作　　者：李泽文 靳书武 卢朝晖 冯勇 陈叶青 张兹勤 LI Zewen;JIN Shuwu;LU Zhaohui;FENG Yong;CHEN Yeqing;ZHANG Ziqin(China Nuclear Power Technology Research Institute Co.,Ltd.,Shenzhen 518000,China)

机构地区：[1]中广核研究院有限公司,广东深圳518000

出　　处：《金属材料与冶金工程》2023年第4期54-58,共5页Metal Materials and Metallurgy Engineering

摘　　要：核反应堆控制棒驱动机构钩爪,采用超低碳奥氏体不锈钢为母材,钩爪摩擦副使用氧乙炔堆焊Stllite-6钴基合金的方式以提高其耐磨损性能,具有抗冲击、韧性好、耐磨损性高的优点。在堆焊过程中母材受氧乙炔碳化火焰的渗碳作用及Stellite-6高碳堆焊层碳迁移的双重影响,高温状态下过饱和碳元素在冷却过程中生成碳化铬聚集在晶界上,造成晶界附近铬元素含量降低,耐腐蚀性能下降。导致奥氏体晶界发生碳化物聚集和晶界贫铬的现象。晶间腐蚀试验表明,氧乙炔钴基合金堆焊的钩爪耐腐蚀性能下降,通过堆焊层材料表征分析出耐腐蚀性能下降的原因,并进行不同优化方法的焊接对比试验,为钩爪堆焊工艺提出了改进方向。The nuclear reactor control rod drive mechanism hook claw is made of ultra-low carbon austenitic stainless steel as the base material,and the friction substrate uses oxyacetylene overlay Stellite-6 cobalt-based alloy to improve its wear resistance,which has the advantages of good impact toughness and high wear resistance.In the overlay process,the base material is subject to the carburizing effect of oxyacetylene carbide flame and the double influence of carbon migration of Stellite-6 high-carbon overlay layer,under the condition of high temperature,supersaturated carbon generates chromium carbide and gathers on the grain boundary during the cooling process,resulting in a decrease in the content of chromium near the grain boundary and decline in corrosion resistance.The austenite grain boundary causes carbide aggregation and the chromium-poor grain boundary.The intergranular corrosion test shows that the corrosion resistance of the hook and claw welded by oxyacetylene cobalt-based alloy decreases,and the reasons for the decrease in corrosion resistance are analyzed through the material characterization of the overlay layer,and the welding comparison test of different optimization methods is conducted,and the improvement direction is proposed for the hook and claw overlay welding process.

关 键 词：钩爪 氧乙炔堆焊 晶间腐蚀 控制棒驱动机构 

分 类 号：TG174.3*6[金属学及工艺—金属表面处理]