A Study on Correlationship between the Induced Plasma and Emission Signals for In-process Monitoring in Stainless Steel Welding of Fiber Laser (Ⅰ)<br> - Properties Changes of the Measured Signals in a Thin Plate Welding -

Lee, Chang-Je; Kim, Jong-Do

doi:2014.32.6.600

J Weld Join > Volume 32(6); 2014 > Article

Research Paper

Journal of Welding and Joining 2014;32(6):600-605.
DOI: https://doi.org/10.5781/JWJ.2014.32.6.64 Published online December 31, 2014.

A Study on Correlationship between the Induced Plasma and Emission Signals for In-process Monitoring in Stainless Steel Welding of Fiber Laser (Ⅰ)
- Properties Changes of the Measured Signals in a Thin Plate Welding -

Chang-Je Lee^*, Jong-Do Kim^**

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

Abstract

The applications by using fiber laser have increased recently. However, due to high beam quality of fiberlaser, it is inappropriate to apply the existing laser welding monitoring technology to the fiber laser welding as it is. On this study, thus, we analyzed emission signal with RMS and FFT for the in-process monitoring during fiber laser welding. 12mm-thick 304L stainless steel sheet was used in fiber laser welding and the result showed as follows: The intensity changes in RMS did not clarify the distinction between full penetration and partial penetration. However, as welding speed increases, specific frequency also increases in regards of frequency analysis by using FFT.

Key Words: Fiber laser, In-process monitoring, Plasma, Emission signal, Lap joint, Butt joint, STS 304L, RMS, FFT