Corrosion Behavior of Mg-steel Laser-TIG Hybrid Welding Joint
SONG Gang, CHI Jiayu, YU Jingwei, LIU Liming
Key Laboratory of Liaoning Advanced Welding and Joining Technology, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024
Abstract: The welding joint of AZ31B magnesium alloy/Q235 steel plate with good forming and mechanical properties was obtained by using laser arc composite filler wire butt welding method. The microstructure and element distribution of welded joints were observed by metallographic microscope and electron probe. The corrosion behavior of welded joints in different regions (magnesium base metal, welding seam, steel base metal) was studied by immersion corrosion test and electrochemical test. The results show that there is anisotropic corrosion in the AZ31B base metal. The galvanic corrosion occurs between the weld metal and the steel base me-tal, the weld line near the interface is corroded seriously, and the Al, Mn element is enriched at the interface, the corrosion tendency is small. There are more steel spatter in the weld, the area around the steel spatter is more serious than the other parts of the weld, and the steel spatter produced during the welding process is unfavorable to the corrosion resistance of the weld. On the one hand, the β phase in the weld prevents the corrosion of the substrate as a barrier layer, and on the other hand, as the cathode in the galvanic corrosion, the corrosion sensitivity of the weld matrix is increased.
1 Wloka J, Laukant H, Glatzel U, et al. Corrosion properties of laser beam joints of aluminium with zinc-coated steel[J]. Corrosion Science,2007,49(11):4243. 2 Lu Gang. Application and development of aluminum, magnesium and titanium alloy materials in automobile industry[J]. Shanghai Nonferrous Metals,2006,27(2):43(in Chinese). 陆刚.铝、镁、钛合金材料在汽车工业中的应用和发展[J].上海有色金属,2006,27(2):43. 3 Pang Eryuan. Analysis of welding technology and joint performance of aluminum alloy/steel foreign metal CMT [D]. Taiyuan: North University of China,2016(in Chinese). 庞二元.铝合金/钢异种金属CMT焊接工艺及接头组织性能分析[D].太原:中北大学,2016. 4 Zhao Xu, Song Gang, Liu Liming. Microstructure analysis of the welding joint of magnesium and steel[J]. Transactions of the China Welding Institution,2006,27(12):53(in Chinese). 赵旭,宋刚,刘黎明.镁和钢异种金属熔焊接头微观组织分析[J].焊接学报,2006,27(12):53. 5 Song Gang, Hu Guanglong, Ren Daxin, et al. Magnesium/steel fil-ling-nickel sandwich laser-arc composite butt fusion welding property[J]. Transactions of the China Welding Institution,2015,36(1):43(in Chinese). 宋刚,胡广龙,任大鑫,等.镁/钢填镍夹层激光-电弧复合对接熔化焊特性[J].焊接学报,2015,36(1):43. 6 Song Gang, Yu Jingwei, Liu Liming. The influence of laser distance on the composite welding of laser-TIG of Mg/steel[J]. Welding Technology,2017,46(5):62(in Chinese). 宋刚,于景威,刘黎明.激光离焦量对镁/钢异种金属激光-TIG复合焊的影响[J].焊接技术,2017,46(5):62. 7 Dong Hairong, Ma Ying, Li Weirong. The microstructure and corrosion resistance of AZ31B magnesium alloy stirring friction welding head [J]. Materials for Mechanical Engineering,2016,40(10):70(in Chinese). 董海荣,马颖,李伟荣.AZ31B镁合金搅拌摩擦焊接头的显微组织及耐腐蚀性能[J].机械工程材料,2016,40(10):70. 8 Zeng R, Chen J, Dietzel W, et al. Corrosion of friction stir welded magnesium alloy AM50[J]. Corrosion Science,2009,51(8):1738. 9 Templeman Y, Ben Hamu G, Meshi L. Friction stir welded AM50 and AZ31 Mg alloys: Microstructural evolution and improved corrosion resistance [J]. Materials Characterization,2017,126:86. 10 Wielage B, Mücklich S, Grund T. Corrosion behaviour of soldered joints of magnesium alloys and dissimilar materials[J]. Microchimica Acta,2006,156(1-2):151. 11 Ben-Hamu G, Eliezer D, Cross C E, et al. The relation between microstructure and corrosion behavior of GTA welded AZ31B magne-sium sheet[J]. Materials Science and Engineering: A,2007,452-453:210. 12 Srinivasan P B, Riekehr S, Blawert C, et al. Mechanical properties and stress corrosion cracking behaviour of AZ31 magnesium alloy laser weldments[J]. Transactions of Nonferrous Metals Society of China,2011,21(1):1. 13 Yuan Bing. Research of joint corrosion of surface treatment on AZ31 magnesium alloy and 45# steel joint samples [D]. Xi’an: Xi’an University of Technology,2006(in Chinese). 袁兵.表面处理AZ31镁合金与45钢连接腐蚀的研究[D].西安:西安理工大学,2006. 14 薛俊峰.镁合金防腐蚀技术[M].北京:化学工业出版社,2010:241. 15 Cui Jianhong, Wu Zhisheng, Gong Xiaoyuan. Research status and development trend of corrosion resistance of Mg alloy welded joint [J]. Aluminium Fabrication,2014(3):45(in Chinese). 崔建红,吴志生,弓晓园.镁合金焊接接头耐腐蚀性能研究现状[J].铝加工,2014(3):45.
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2018, Vol. 32 
