Study on Solidification Cracking Under High-speed Narrow Gap Welding with Tandem Torches

Abstract

In this research, the influence of various factors on solidification cracking under high-speed gap welding was investigated by nonlinear thermal-elastic-plastic analysis using the finite element method (FEM). To investigate the formation of cracks, the plastic strain increment in the brittleness temperature range (BTR) was introduced. In addition, to perform thermal-elastic-plastic analysis of a practical three-dimensional model, Idealized Explicit FEM was employed. In the simulations, the penetration shape was compared between the experimental measurement and the analyses to evaluate the analysis accuracy. As a result, it was found that the penetration shapes agree with each other. The heat input, welding speed, and torch distance were changed and the distribution of the BTR plastic strain increment was also compared to show the influence of the welding conditions. From the investigations, it was found that the BTR plastic strain increment increases with heat input, welding speed and decreases with torch distance.