深冷处理对轨道车辆用耐候钢镀层板点焊电极帽寿命的影响  

Influence of Deep Cryogenic Treatment on Life of Electrode Cap during Spot Welding of Atmosphere Corrosion Resistant Steel Coated Plates for Rail Vehicles

作　　者：倪凯 陈春焕[1] 潘金芝[1] NI Kai;CHEN Chunhuan;PAN Jinzhi(School of Materials Science and Engineering,Dalian Jiaotong University,Dalian 116028,China)

机构地区：[1]大连交通大学材料科学与工程学院,辽宁大连116028

出　　处：《热加工工艺》2022年第15期41-45,共5页Hot Working Technology

摘　　要：针对轨道车辆用耐候钢镀层板点焊电极帽寿命低的问题,分别使用深冷处理前后的CuCrZr电极帽进行寿命试验,观测电极帽端面直径变化及接头质量,对失效电极帽形貌、微观组织和硬度分布进行分析。结果表明:耐候钢镀层板点焊CuCrZr电极帽的最主要失效形式为由塑性变形引起的端面尺寸增大,深冷处理使CuCrZr电极帽寿命由原来的90焊点提升至180焊点。寿命提高的原因在于深冷处理提高了CuCrZr的导电性能和导热性能,使电极帽产热减少,散热快,降低电极帽与工件镀层接触面的过热程度,从而减缓粘损和塑性变形速度。Aiming at the problem of low life of electrode cap during spot welding of atmosphere corrosion resistant steel coated plates for railway vehicle,the CuCrZr electrode caps with deep cryogenic treatment(DCT) and non-DCT were used for life test.The diameter change of electrode cap end face and joint quality were observed,the morphology,microstructure and hardness distribution of the failed electrode cap were analyzed.The results indicate that during spot welding of atmosphere corrosion resistant steel coated plate,the main failure mode of the CuCrZr electrode cap is the rapid increase of section size caused by plastic deformation,the life of CuCrZr electrode cap is increased from 90 to 180 points by DCT.The reason for life improvement is that DCT improves the conductive and thermal properties of CuCrZr,reduces the heat production of the electrode cap,dissipates heat quickly,reduces the overheating degree of the contact surface between the electrode cap and the coating,and thus slows down the speed of adhesion and plastic deformation.

关 键 词：电阻点焊 耐候钢 电极帽寿命 深冷处理 

分 类 号：TG438.2[金属学及工艺—焊接]