Research on the Structure and Performance of Local Dry Underwater Laser Welding of 304 Stainless Steel

doi:10.3901/JME.2025.20.072

Abstract

Abstract: The underwater welding process is influenced by various factors, including water intrusion, cooling effects, and their impact on the microstructure and properties of the weld joint. To investigate the effects of the underwater environment on the performance of 304 stainless steel partial dry laser welding joints, experiments were conducted using a self-designed double-layer gas drainage device for local dry underwater laser welding of 304 stainless steel at a water depth of 50 mm. The underwater and terrestrial welds were studied under laser power of 3.0 kW, welding speed of 0.8 m/min, and inner gas flow rate of 25 L/min. The results indicated that water intrusion during the welding process caused partial oxidation of the weld seam surface. The cooling effect of water reduced the peak temperature and cooling rate during the welding process, leading to an increase in nucleation rate and undercooling, promoting grain refinement, and altering the solidification mode, resulting in a microstructure consisting of austenite and partial ferrite after solidification. The average hardness of the underwater joint was higher than that of the terrestrial joint, and the tensile strength could reach 97% of the terrestrial joint. Fracture morphology and mechanism analysis revealed that both joints exhibited ductile fracture with micro-pore aggregation, while the underwater joint exhibited some brittle characteristics. Moreover, the cooling effect of water exacerbated the segregation of Cr and Ni elements, reducing the corrosion resistance of the underwater joint.

Key words: 304 stainless steel, local dry method, laser welding

CLC Number:

TG456

ZHAO Yongqing, ZHANG Qinghua, TIAN Yifeng, CHEN Yingjie, SUN Qingjie, LIU Yibo, LI Xingshuai. Research on the Structure and Performance of Local Dry Underwater Laser Welding of 304 Stainless Steel[J]. Journal of Mechanical Engineering, 2025, 61(20): 72-80.

References

[1] 韩鹏程. 核反应堆用奥氏体不锈钢的力学行为研究[D].上海：上海交通大学，2012. HAN Pengcheng. Study on mechanical behavior of austenitic stainless steel for nuclear reactor[D]. Shanghai：Shanghai Jiao Tong University，2012.
[2] 黄松岭，孙洪宇，王珅，等. 压水堆核电站无损检测与状态监测研究综述[J]. 机械工程学报，2022，58(4)：1-13. HUANG Songling，SUN Hongyu，WANG Shen，et al. A review of nondestructive testing and condition monitoring of pressurized water reactor nuclear power plants[J]. Journal of Mechanical Engineering，2022，58(4)：1-13.
[3] 马兆炫，刘一搏，王建峰，等. 双相不锈钢水下局部干法TIG焊接工艺[J]. 机械工程学报，2022，58(4)：48-54. MA Zhaoxuan，LIU Yibo，WANG Jianfeng，et al. Underwater local dry TIG welding process for duplex stainless steel[J]. Journal of Mechanical Engineering，2022，58(4)：48-54.
[4] GAO H，JIAO X ，ZHOU C，et al. Study on remote control underwater welding technology applied in nuclear power station[J]. Procedia Engineering，2011，15：4988-4993.
[5] ŁABANOWSKI J. Development of under-water welding techniques[J]. Welding International，2011，25(12)：933-937.
[6] ROWE M，LIU S. Recent developments in underwater wet welding[J]. Science and Technology of Welding and Joining，2001，6(6)：387-396.
[7] 付艳恕，卢聪，叶小军，等. 激光材料加工熔池流动行为实验研究进展[J]. 机械工程学报，2023，59(5)：291-306. FU Yanshu，LU Cong，YE Xiaojun，et al. Research progress on the experimental study of melt pool flow behavior in laser material processing[J]. Journal of Mechanical Engineering，2023，59(5)：291-306.
[8] OLIVEIRA J P，SHAMSOLHODAEI A，SHEN J，et al. Improving the ductility in laser welded joints of CoCrFeMnNi high entropy alloy to 316 stainless steel[J]. Materials & Design，2022，219：110717.
[9] TAN Z，PANG B，OLIVEIRA J P，et al. Effect of S-curve laser power for power distribution control on laser oscillating welding of 5A06 aluminum alloy[J]. Optics & Laser Technology，2022，149：107909.
[10] TESHOME F B，PENG B，OLIVEIRA J P，et al. Role of Pd interlayer on NiTi to Ti6Al4V laser welded joints：Microstructural evolution and strengthening mechanisms[J]. Materials & Design，2023，228：111845.
[11] ZHANG X，ASHIDA E，SHONO S，et al. Effect of shielding conditions of local dry cavity on weld quality in underwater Nd：YAG laser welding[J]. Journal of Materials Processing Technology，2006，174(1-3)：34-41.
[12] LI C，ZHU J，CAI Z，et al. Microstructure and corrosion resistance of underwater laser cladded duplex stainless steel coating after underwater laser remelting processing[J]. Materials，2021，14(17)：4965.
[13] 秦航，蔡志海，张平，等. 中碳钢水下湿法激光焊接焊缝成形行为与性能[J]. 中国表面工程，2019，32(3)：130-137. QIN Hang，CAI Zhihai，ZHANG Ping，et al. Forming behavior and performance of underwater wet laser welding weld of medium carbon steel[J]. China Surface Engineering，2019，32(3)：130-137.
[14] 杜士瑄. 921A钢水下激光填丝焊接成形工艺优化研究[D]. 北京：北京化工大学，2020. DU Shixuan. Research on optimization of 921A underwater steel laser wire filling welding forming process[D]. Beijing：Beijing University of Chemical Technology，2020.
[15] 王建峰，孙清洁，张顺，等. 基于电弧气泡调控的水下湿法焊接稳定性研究[J]. 机械工程学报，2018，54(14)：50-57. WANG Jianfeng，SUN Qingjie，ZHANG Shun，et al. Stability of underwater wet welding based on arc bubble control[J]. Journal of Mechanical Engineering，2018，54(14)：50-57.
[16] GUO Ning，CU Yulong，XING Xiao，et al. Relationship between weld quality and optical emissions in underwater Nd：YAG laser welding[J]. Optics and lasers in engineering，2004，41(5)：717-730.
[17] GUO Ning，FU Yulong，XING Xiao，et al. Underwater local dry cavity laser welding of 304 stainless steel[J]. Journal of Materials Processing Technology，2018，260：146-155.
[18] 王东，朱德才，吕旭伟. 水下焊接技术在核电站建设中的应用与研究展望[J]. 焊接技术，2021(2)：1-5，105. WANG Dong，ZHU Decai，LÜ Xuwei. Application and Research outlook of underwater welding technology in nuclear power plant construction[J]. Welding Technology，2021(2)：1-5，105.
[19] 卞向南，邵长磊，张晓春，等. 基于激光焊接技术的水下焊缝修复系统研究[J]. 机械研究与应用，2020，33(6)：52-54. BIAN Xiangnan，SHAO Changlei，ZHANG Xiaochun，et al. Research on underwater weld repair system based on laser welding technology[J]. Mechanical Research and Application，2020，33(6)：52-54.
[20] WAHBA M，MIZUTANI M，KATAYAMA S. Single pass hybrid laser-arc welding of 25 mm thick square groove butt joints[J]. Materials & Design，2016，97：1-6.
[21] 刘海园，郜晓溪，王渊博，等. 时效温度对马氏体不锈钢激光焊接接头组织和性能的影响[J]. 机械工程学报，2012，48(16)：69-73. LIU Haiyuan，GAO Xiaoxi，WANG Yuanbo，et al. Effect of aging temperature on microstructure and properties of martensitic stainless steel laser welded joints[J]. Journal of Mechanical Engineering，2012，48(16)：69-73.
[22] 卢庆华，郭崇，郭屹，等. 不同冷却条件下激光焊接接头性能研究[J]. 机械工程学报，2015，51(10)：41-47. LU Qinghua，GUO Chong，GUO Yi，et al. Study on the performance of laser-welded joints under different cooling conditions[J]. Journal of Mechanical Engineering，2015，51(10)：41-47.
[23] CUI C Y，CUI X G，REN X D，et al. Microstructure and microhardness of fiber laser butt welded joint of stainless-steel plates[J]. Materials & Design，2013，49：761-765.
[24] ORŁOWSKA M，URA-BIŃCZYK E，OLEJNIK L，et al. The effect of grain size and grain boundary misorientation on the corrosion resistance of commercially pure aluminium[J]. Corrosion Science，2019，148：57-70.
[25] 朴楠，陈吉，尹成江，等. 超细晶304L不锈钢在含Cl^-溶液中点蚀行为的研究[J]. 金属学报，2015，51(9)：1077-1084. PIAO Nan，CHEN Ji，YIN Chengjiang，et al. Study on pitting corrosion behavior of ultrafine-grained 304L stainless steel in Cl^- containing solution[J]. Acta Metallurgica Sinica，2015，51(9)：1077-1084.
[26] WANG X，HE P，ZHOU Q，et al. Effects of laser welding on the microstructure evolution and corrosion resistance of a novel nitrogen-containing austenitic stainless steel QN2109[J]. Journal of Materials Research and Technology，2023，24：303-317.
[27] ZHANG J，HU K，ZHAO J，et al. Effect of heat input on microstructure and corrosion resistance in heat affected zone of 304 stainless steel joint by laser welding[J]. Materials Today Communications，2022，30：103054.