In view of the insufficient toughness of the GPa-grade deposited metal, four groups of welding wires were designed to study the effects of Al and Mg elements on the microstructure and mechanical properties of metal cored welding wires. The microstructure of the deposited metal was characterized by scanning electron microscopy (SEM). The mechanical properties of the deposited metal were characterized by mechanical properties test. The results show that the deposited metal mainly consists of martensite and bainite. With the increase of Al and Mg contents from 0Al-0Mg to 0.3Al-0.9Mg, the content of O decreases from 0.030 8% to 0.014 3%, and the content of coalesced bainite decreases while that of lath martensite increases. and the inclusions were transformed from traditional oxides including Fe, Al, Si, Mn, etc. to spherical and fine particles mainly composed of Al and Mg oxides inclusions. Compared with 0Al-0Mg group, the average size of the inclusion in 0.3Al-0.9Mg group decreases by 0.13 μm, the tensile strength was increased by 152 MPa, and the impact absorption energy was increased by 11 J (−20 ℃).
[1] Khurshid M, Barsoum Z, Mumtaz N A. Ultimate strength and failure modes for fillet welds in high strength steels[J]. Materials & Design, 2012, 40:36-42.
[2] Lan L, Kong X, Qiu C, et al. Influence of microstructural aspects on impact toughness of multi-pass submerged arc welded HSLA steel joints[J]. Materials & Design, 2015, 90:488-498.
[3] Schneider C, Ernst W, Schnitzer R, et al. Welding of S960MC with undermatching filler material[J]. Welding in the World, 2018, 62(4):801-809.
[4] Keehan E, Karlsson L, Andrén H O, et al. Influence of carbon, manganese and nickel on microstructure and properties of strong steel weld metals:part 2-impact toughness gain resulting from manganese reductions[J]. Science and Technology of Welding and Joining, 2006, 11(1):9-18.
[5] Keehan E, Karlsson L, Andrén H O, et al. Influence of carbon, manganese and nickel on microstructure and properties of strong steel weld metals:part 3-increased strength resulting from carbon additions[J]. Science and Technology of Welding and Joining, 2006, 11(1):19-24.
[6] Seo J S, Lee C H, Kim H J. Influence of oxygen content on microstructure and inclusion characteristics of bainitic weld metals[J]. ISIJ International, 2013, 53:279-285.
[7] 苏小虎, 栗卓新, 马思鸣, 等. 氧含量及夹杂物对高强钢金属芯焊丝E120C-K4熔敷金属冲击韧性的影响[J]. 材料导报, 2020, 34(6):11049-11052
Su Xiaohu, Li Zhuoxin, Ma Siming, et al. Effect of oxygen content and inclusions on impact toughness in deposited weld metal of high strength steel metal cored wire E120C-K4[J]. Materials Reports, 2020, 34(6):11049-11052
[8] 于航, 侴树国, 王慧源, 等. 氧对00Cr13Ni5Mo熔敷金属组织和韧性的影响[J]. 焊接学报, 2014, 35(6):109-112
Yu Hang, Chou Shuguo, Wang Huiyuan, et al. Effect of oxygen on toughness and microstructure of 00Cr13Ni5Mo deposited metal[J]. Transactions of the China Welding Institution, 2014, 35(6):109-112
[9] 贾玉力, 李向阳, 杜兵, 等. 马氏体不锈钢MAG焊熔敷金属性能的影响[J]. 焊接, 2000(7):23-25
Jia Yuli, Li Xiangyang, Du Bing, et al. Influence of active gas on properties of martensite stainless steel deposited metal in Ar-rich MAG[J]. Welding & Joining, 2000(7):23-25
[10] 秦名朋, 李东洁, 陆善平, 等. He 与He + CO2双层气流保护TIG焊工艺[J]. 焊接学报, 2011, 32(11):49-52
Qin Mingpeng, Li Dongjie, Lu Shanping, et al. He and He + CO2 double shield TIG welding process[J]. Transactions of the China Welding Institution, 2011, 32(11):49-52
[11] 蒋欢欢. CO2气体保护焊铝脱氧焊丝的研究[D]. 天津:天津大学, 2012.
Jiang Huanhuan. Study on aluminum deoxidized wire for CO2 gas shielded welding[D]. Tianjin:Tianjin University, 2012.
[12] 尹士科. 焊接材料实用基础手册第二版[M]. 北京:化学工业出版社, 2015.
Yin Shike. Practical fundamentals of welding materials[M]. Beijing:Chemical Industry Press, 2015.
[13] 刘政军, 裘荣鹏, 武丹, 等. 微合金元素镍和铌对金属粉芯焊丝焊接接头性能的影响[J]. 焊接学报, 2017, 38(8):1-6, 68
Liu Zhengjun, Qiu Rongpeng, Wu Dan, et al. Effect of micro-alloying nickel and niobium elements on mechanical properties of welded joint with metal powder-cored wire[J]. Transactions of the China Welding Institution, 2017, 38(8):1-6, 68
[14] 焦帅杰, 王国佛, 贾玉力, 等. 超级马氏体不锈钢焊丝MAG焊熔敷金属冲击性能优化[J]. 焊接学报, 2022, 43(3):93-100
Jiao Shuaijie, Wang Guofu, Jia Yuli, et al. Impact performance optimization of supermartensitic stainless steel welding wire deposited metal by MAG welding[J]. Transactions of the China Welding Institution, 2022, 43(3):93-100
[15] 吴炳智, 徐玉君, 安洪亮, 等. 高强焊丝熔敷金属力学性能及组织分析[J]. 焊接学报, 2014, 35(4):53-57
Wu Bingzhi, Xu Yujun, An Hongliang, et al. Property and microstructure of deposited metal with high strength wire[J]. Transactions of the China Welding Institution, 2014, 35(4):53-57
[16] 安同邦, 田志凌, 单际国, 等. 保护气对 1000 MPa级熔敷金属组织及力学性能的影响[J]. 金属学报, 2015, 51(12):1489-1499
An Tongbang, Tian Zhiling, Shan Jiguo, et al. Effect of shielding gas on microstructure ad performance of 1000 MPa grade deposited metals[J]. Acta Metallurgica, 2015, 51(12):1489-1499
[17] 尹士科, 王移山. 低合金钢焊接特性及焊接材料[M]. 北京:化学工业出版社, 2014.
Yin Shike, Wang Yishan. Welding characteristics and welding materials of low alloy steel[M]. Beijing:Chemical Industry Press, 2014.
[18] Caballero F G, Chao J, Cornide J, et al. Toughness deterioration in advanced high strength bainitic steels[J]. Materials Science and Engineering:A, 2009, 525(1-2):87-95.
[19] Lan H F, Du L X, Li Q, et al. Improvement of strength-toughness combination in austempered low carbon bainitic steel:the key role of refining prior austenite grain size[J]. Journal of Alloys and Compounds, 2017, 710(2):702-710.
[20] Das A, Tarafder S. Experimental investigation on martensitic transformation and fracture morphologies of austenitic stainless steel[J]. International Journal of Plasticity, 2009, 25(11):2222-2247.
