Characteristics of Plasma Emission Signals in Fiber Laser Welding of API Steel (Ⅲ)

Lee, Chang-Je; Kim, Jong-Do; Kim, Yu-Chan

doi:2013.31.3.60

J Weld Join > Volume 31(3); 2013 > Article

Research Paper

Journal of KWJS 2013;31(3):60-65.
DOI: https://doi.org/10.5781/KWJS.2013.31.3.60 Published online June 30, 2013.

Characteristics of Plasma Emission Signals in Fiber Laser Welding of API Steel (Ⅲ)

Chang-Je Lee, Jong-Do Kim, Yu-Chan Kim

Correspondence: Jong-Do Kim,
Email: jdkim@hhu.ac.kr

Abstract

Ar, N2, and He are the conventional kind of shield gas that are used for laser welding. Many researches on the impact of laser welding shield gas have been done, and it is on going until now. However, there are few studies that analyze the changes and differences of the plasma emission signal. Therefore, in this study, we evaluated the change in the penetration characteristics according to the type of shield gas during fiber laser welding impacts to the plasma signal. As a result, if was checked that the difference in molecular weight of Ar, N2, and He affects to the amount of spatter, and also found that the measured plasma radiation signal changes similar to the order of the molecular weight of the gases. Especially, clear change on the signal intensity per each shield gas was measured through RMS, and found that the shield gas was nothing to do with the FFT analyzed result.

Key Words: Fiber laser, Laser welding, Plasma, Emission Signal, Shield gas, Spatter