Journal of Welding and Joining

9: J Weld Join. 2014;32(2):144-147. Published online May 14, 2014.
DOI: https://doi.org/10.5781/JWJ.2014.32.2.18; Effect of Preheat Temperature on Diffusible Hydrogen Content in Weld Metal Deposited using Flux Cored Wire; Dong Yoon Kim^*, In Sung Hwang^*, Dong Cheol Kim^*, Moon Jin Kang^*; Corresponding author: Dong Cheol Kim ,Email: dckim@kitech.re.kr

Abstract: Cold cracking of weldment is one of the most serious welding problems. A sufficient quantity of diffusible hydrogen, a residual stress, and a sensitive microstructure are the causes of cold cracking. Removal of any one of these factors can be used to prevent cold cracking. Application of flux cored arc welding process is increasing due to high productivity and easiness of welding. In addition, to prevent cold cracking in the HAZ or weldment, preheat temperature and interpass temperature have to be controlled. In this study, the effect of preheat temperature on the levels of diffusible hydrogen in the weld metal deposited using flux cored wire was examined. The levels of preheat temperature of base metal specimen were ambient temperature, 50, 100 and 150 ℃ respectively. The result showed that the increase of preheat temperature was a linear relationship with reduction of diffusible hydrogen content in weldment.

Keywords :Diffusible hydrogen content, Hydrogen induced cracking, Flux cored wire, Preheat temperature, Delay time