Residual Stress and Deformation Analysis in Butt Welding on 6 mm SUS304 Steel with Jig Constraints Using Gas Metal Arc Welding

Chi-Liang Kung,Cheng-Kuang Hung,Chao-Ming Hsu,Cheng-Yi Chen

doi:10.3390/app7100982

Abstract

This article proposes a novel method for analyzing residual stress and deformation in butt welding on 6 mm SUS304 stainless steel plates, using MSC.MARC, a commercial finite element method software, to find the best location for jig fixtures that will minimize welding deformation. Simulation and experimental studies show that a distance of 100 mm between the jig center and the welding bead center is best for inhibiting welding deformation when the jigs experience downward displacement at 0 mm on the steel plate; the total displacement is only about 1.1 mm in the case of a 300 × 250 × 6 mm SUS304 steel plate. In addition, a numerical model shows that four jigs with pitches of 200 mm can better reduce welding deformation than six jigs with pitches of 100 mm. The largest residual stress after welding occurs around the weld bead center, and the residual stress away from the welding bead center increases gradually when jigs have been applied on the steel plate to prevent deformation. The reaction force of the jigs on the steel plate has no further effect in reducing deformation. We conclude that commercially available jigs can inhibit deformation during the welding process.

Highlights

The thermal energy produced during the welding process in the area around the welding beads is not distributed
Contraction is caused by the temperature of the heat affected zone (HAZ)—the area where the filler material is applied to the welding plates—in conjunction with the temperature of the surrounding areas
We propose the best position for applying a jig fixture to prevent welding deformation in a workpiece

Summary

Introduction

The thermal energy produced during the welding process in the area around the welding beads is not distributed. Contraction is caused by the temperature of the heat affected zone (HAZ)—the area where the filler material is applied to the welding plates—in conjunction with the temperature of the surrounding areas. This internal tension arises from solidification of the filler metal and cooling of the material. When the welding workpiece cools to room temperature, the filler metal and the welding beads respond differently, leading to a problematic contraction on the welding plate This results in high residual stress around the area where the heat affects the welding beads and the workpiece, causing a permanent deformation to offset the internal stress that the welding produces on the plate. If such deformation cannot be prevented, the strength of the workpiece will likely be compromised, at best reducing the lifespan of the material and at worst causing serious accidents

Methods

Results

Conclusion