热影响区连续孔隙状裂纹的表征及产生机理
Characterization and formation mechanisms of continuous porosities-like cracks in the heat-affected zone
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摘要: 以凝固温度范围极宽的合金为对象，研究焊接热影响区的液化现象，表征该区域中出现的连续孔隙状裂纹，并分析其产生机理. 结果表明，连续孔隙状裂纹的产生与母材中残余第二相颗粒的连续分布、热影响区中出现的严重液化现象及液相的流失密切相关. 其产生机理在于：焊接加热时，第二相颗粒加剧了晶界液化的程度，并形成连接热影响区和焊接熔池的液相通道；冷却过程中，由于熔池区熔体体积收缩促使热影响区中的液相流向熔池；凝固末期，通道因胞状晶生长而被堵塞，导致液相无法从熔池回填，从而在热影响区形成连续孔隙状裂纹.Abstract: The alloy with extreme wide solidification temperature range was employed to investigate liquation phenomenon in the heat-affected zone (HAZ) of welded joint. The continuous porosities-like liquation cracks were characterized and their formation mechanisms were analyzed and discussed in details. The results show that the occurrence of continuous porosities-like liquation cracking is closely related to the continuously distributed residual particles of second phase in the base metal, seriously constitutional liquation of the HAZ and the loss of liquid phase in it. The formation mechanisms demonstrated that as the heat source approaching the residual particles of second phase melted, which prompted the extent of liquation along the grain boundaries in the HAZ, and the liquid exchange channels were built between the fusion zone and HAZ. As the heat source leaving, the liquid in HAZ was sucked into the fusion zone under the force produced by cooling shrinkage of the molten metal in fusion zone. At the final stage of solidification, the porosities-like liquation cracks were formed due to the absence of liquid caused by blocking of the channels for liquid filling back from the fusion zone.
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Keywords:
- weld defect /
- heat-affected zone /
- liquation cracking /
- partially melted zone /
- hot cracks
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[1] Shi Mingxiao, Zhao jian, Chen Shujin, et al. Effect of W/Cu composite filler metals on the microstructure and mechanical properties of laser welded pure niobium/304 stainless steel joint[J]. China Welding, 2016, 25(4):9-13. [2] 张楠,田志凌,张熹,等. Q690CFD高强钢焊接热影响区的断裂韧性[J].焊接学报, 2018, 39(1):26-31 Zhang Nan, Tian Zhiling, Zhang Xi, et al. Fracture toughness of CGHAZ of Q690CFD high-strength steel[J]. Transactions of the China Welding Institution, 2018, 39(1):26-31 [3] 黄勇,孙文磊,周超军,等.基于激光熔覆的再制造零件可视化损伤修复区域规划[J].焊接学报, 2017, 38(11):51-57 Huang Yong, Sun Wenlei, Zhou Chaojun, et al. Planning of repair area of visual damage on component to be remanufactured by laser cladding[J]. Transactions of the China Welding Institution, 2017, 38(11):51-57 [4] 赵琳,塚本进,荒金吾郎,等. 10 kW光纤激光焊接缺陷的形成[J].焊接学报, 2015, 36(7):55-58 Zhao Lin, Tsukamoto S, Arakane G, et al. Formation of defects in 10 kW fiber laser welding[J]. Transactions of the China Welding Institution, 2015, 36(7):55-58 [5] Messler R W. Principles of welding[M]. Weinheim:Wiley-VCH, 2004. [6] Huang C, Kou S. Partially melted zone in aluminum welds-liquation mechanism and directional solidification[J]. Welding Journal, 2000, 79(5):113-120. [7] Huang C, Kou S. Partially melted zone in aluminum welds-planar and cellular solidification[J]. Welding Journal, 2001, 80(2):46-53. [8] Huang C, Kou S. Partially melted zone in aluminum welds-solute segregation and mechanical behavior[J]. Welding Journal, 2001, 80(1):9-17. [9] Yu Zhaohui, Yan Hongge, Chen Jihua, et al. Effect of Zn content on the microstructures and mechanical properties of laser beam-welded ZK series magnesium alloys[J]. Journal of Materials Science, 2010, 45(14):3797-3803. [10] Kou S. Welding metallurgy[M]. Hoboken:Wliley-Interscience, 2002. [11] 陈振华,严红革,陈吉华,等.镁合金[M].北京:化学工业出版社, 2004. -
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