Local dry underwater welding of 304 stainless steel based on a microdrain cover
Local dry underwater welding of 304 stainless steel based on a microdrain cover
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DOI：
10.1016/j.jmatprotec.2018.12.029
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发表时间：
2019-06-01
影响因子：
6.3
通讯作者：
Fan, Wenyan
中科院分区：
文献类型：
--
作者：
Han, Leigang;Wu, Xiangmiao;Fan, Wenyan
为了提高乏燃料池水下干焊修复工艺的性能，设计了一种基于收缩喷嘴原理的双气幕结构微漏盖，并对其焊接工艺进行了研究。以美国钢铁协会（AISI） 304不锈钢为母材，进行了14组不同参数的直流脉冲气体保护水下焊接试验。焊接实验水深为40 cm。主要分析了焊缝成形、显微组织和显微硬度以及焊缝的力学性能，并选择了最佳实验参数。将微漏罩与优化后的焊接参数相结合，实现了稳定的水下焊接过程。焊缝宽度均匀，补强高度适中，几乎无缺陷，无气孔。焊缝区基体组织为奥氏体，晶界混入一定量的δ -铁素体，具有良好的耐蚀性。热影响区出现拉伸断裂，平均屈服强度超过500 MPa，断口呈韧窝状。
To improve the performance of the underwater dry welding repair process in nuclear spent fuel pools, a microdrain cover based on the shrinkage nozzle principle with a dual air curtain structure was designed, and a welding process was performed for investigation. American Iron and Steel Institute (AISI) 304 stainless steel was used as the base metal, and 14 sets of direct current (DC) pulse gas-shielded underwater welding experiments with different parameters were conducted. The water depth of the welding experiment was 40 cm. The main analysis included the weld formation, microstructure and microhardness as well as the mechanical properties of the weld, and the best experimental parameters were selected. A stable underwater welding process was achieved by using the microdrain cover combined with the optimized welding parameters. The weld width was uniform, the reinforcement height was moderate, there were almost no defects, and no porosity were observed. Austenite was the matrix structure of the weld zone, and the grain boundary was mixed with a certain amount of delta-ferrite, thereby showing a good corrosion resistance. Tensile fracturing occurred in the heat-affected zone (HAZ), the average yield strength exceeded 500 MPa, and the fracture displayed dimples.