熔化极气体保护焊导电嘴载流磨损及使用寿命的研究进展  

Progress on Current-carrying Wear and Service Life of Contact Tube for GMAW

作　　者：栗卓新[1] 丛兴 李红[1] Kim Hee Jin LI Zhuoxin;CONG Xing;LI Hong;Kim Hee Jin(School of Materials Science and Engineering,Beijing University of Technology,Beijing 100020,China;Advanced Joining Research Team,Korea Institute of Industrial Technology,Cheonan-si 330-825,Korea)

机构地区：[1]北京工业大学材料科学与工程学院,北京100020 [2]韩国工业技术研究院熔焊研究组,天安330-825

出　　处：《材料导报》2020年第19期19128-19133,19151,共7页Materials Reports

基　　金：国家自然科学基金(51574011);北京市自然科学基金(3202002)。

摘　　要：现代制造业要求焊接技术向智能化、连续化、绿色化发展,目前熔化极气体保护焊焊接过程中焊丝对导电嘴的磨损率过大,频繁地停工更换和清理零部件限制了熔化极气体保护焊自动化焊接的发展。电接触条件下的载流磨损是导致材料磨损率过大的重要原因,主要体现在两个方面:(1)电接触产生焦耳热,使环境温度大幅提高,局部温度甚至超过500℃,造成电接触材料发生软化;(2)电接触点的不断运动和变化导致产生微观电弧,造成局部材料的剧烈熔融和氧化。因电接触造成的电气磨损与机械磨损相互加剧,大幅缩短了导电嘴器件的使用寿命。接触电阻是产生焦耳热和微观电弧的关键因素,镀铜钢焊丝与导电嘴之间的接触电阻值约为1.6 mΩ,而对于无镀铜钢焊,该值提高到约2.5 mΩ。导电嘴使用寿命随接触电阻、焊接电流、送丝速度增大而缩短;法向接触载荷一方面增大机械磨损,另一方面减少电气磨损,因此对导电嘴寿命有着复杂影响。高强度、高导电性导电嘴材料有利于延长导电嘴使用寿命,利用双相析出沉淀强化的Cu-Cr-Zr系铜合金能在显著提高材料强度的同时尽可能地减少因合金固溶导致的电导率损失,与此同时,石墨基、粉末冶金及复合材料导电嘴也有一定的实用性和研究价值。光洁平整的焊丝表面有利于延长导电嘴使用寿命,在无镀铜焊丝表面制备润滑性涂层能进一步提升导电嘴磨损性能。由于焊接条件的特殊性,表面涂层需兼具高温稳定性、高导电性等特征,具有表面效应和小尺寸效应的固体润滑剂在这方面具有极大的优势和应用前景。本文综述了熔化极气体保护焊导电嘴载流磨损机理的研究进展,从工艺参数、导电嘴材料、焊丝表面状态等方面分析了影响导电嘴载流磨损的因素和延长导电嘴寿命的可行方法,对减少导电嘴磨损,延长其寿命,推动机器�Modern manufacturing requires welding technology to be intelligence,continuous and environmentally friendly.At present,the high wear rate of the contact tube lead to frequent downtime and overhaul during welding,limiting the development of the gas metal arc welding.The current-carrying wear under electrical contact conditions is an important cause of excessive wear and it is mainly reflected in two aspects:(1)Joule heat generated by electrical contact causes the ambient temperature to increase greatly,and the local temperature even exceeds 500℃,causing softening of electrical contact materials;(2)constant movement and change of electrical contacts leads to microscopic arcing,causing intense melting and oxidation of local materials.The mechanical wear and electrical wear caused by electrical contact are mutually intensified,greatly reducing the service life of contact tube.Contact resistance is vital to the generation of Joule heat and micro-arc.The contact resistance between the copper-coated steel wire and the contact tube is 1.6 mΩ,while for copper-free steel wire this value is increased to 2.5 mΩ.The life of the contact tube decreases with the increase of contact resistance,welding current and wire feed speed;the normal contact load increases the mechanical wear on the one hand and reduces the electrical wear on the other hand,so it has a complicated influence on the life of the contactor.The use of high-strength and high-conductivity material is beneficial to improve the service life of the contactor.Cu-Cr-Zr based copper alloy strengthened by two-phase precipitation can significantly improve the material strength while minimizing the conductance loss caused by solid solution.In addition,graphite-based,powder metallurgy and composite material contact tube have certain practicability and is worth studying.A smooth and flat surface of the wire helps to extend the service life of the contact tube and surface lubricity coating prepared on non-copper coated wire can further improve its wear property.Welding co

关 键 词：熔化极气体保护焊 工艺性能 导电嘴寿命 载流磨损 

分 类 号：TG422.3[金属学及工艺—焊接]