Abstract The chemical composition of a weld metal determines the resulting solidification mode of stainless steel and the consequent weld metal quality. In this work tungsten inert gas (TIG) welding of EN grade 1.4435 austenitic stainless steel was monitored using laser-induced breakdown spectroscopy (LIBS) for the in situ measurement of chemical composition changes. This research aims to prototype a real-time chemical composition analysis system for welding applications and prove the feasibility of such quality control loop. LIBS was used to investigate in situ the monitoring of metal vaporization during TIG welding. We found Mn vapor formation above the weld pool and subsequent condensation of Mn on the weld metal surface using LIBS. Post-weld line scans were conducted by LIBS on various welds produced with different welding currents. Local changes of Ni and Mn were observed at higher welding currents. The results are in good agreement with the literature and proved that LIBS can be used in situ to inspect the TIG welding process.

中文翻译：

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用激光诱导击穿光谱法测量钨-惰性气体奥氏体不锈钢焊缝的原位化学成分分析

摘要 焊缝金属的化学成分决定了不锈钢的凝固方式和焊缝金属质量。在这项工作中，使用激光诱导击穿光谱 (LIBS) 对 EN 等级 1.4435 奥氏体不锈钢的钨惰性气体 (TIG) 焊接进行监测，以原位测量化学成分变化。本研究旨在为焊接应用建立一个实时化学成分分析系统的原型，并证明这种质量控制回路的可行性。LIBS 用于研究 TIG 焊接过程中金属汽化的原位监测。我们使用 LIBS 发现熔池上方有 Mn 蒸气形成，随后 Mn 在焊缝金属表面冷凝。LIBS 对不同焊接电流产生的各种焊缝进行焊后线扫描。在较高的焊接电流下观察到 Ni 和 Mn 的局部变化。结果与文献吻合较好，证明LIBS可用于TIG焊接过程的原位检测。