Investigation of the Residual Stress in a Multi-Pass T-Welded Joint Using Low Transformation Temperature Welding Wire.

Zhongyuan Feng,Fenggui Lu,Seiichiro Tsutsumi,Ninshu Ma

doi:10.3390/ma14020325

Abstract

We investigated whether low transformation temperature (LTT) welding materials are beneficial to the generation of compressive residual stress around a weld zone, thus enhancing the fatigue performance of the welded joint. An experimental and numerical study were conducted in order to analyze the residual stress in multi-pass T-welded joints using LTT welding wire. It was found that, compared to the conventional welded joint, greater tensile residual stress was induced in the flange plate of the LTT welded joints. This was attributed to the reheat temperature of the LTT weld pass during the multi-pass welding. The formerly-formed LTT weld pass with a reheat temperature lower than the austenite finish temperature converted the compressive residual stress into tensile stress. The compressive residual stress was generated in the regions with a reheat temperature higher than the austenite finish temperature, indicating that LTT welding materials are more suitable for single-pass welding.

Highlights

It is well known that fusion welding has been applied to a large number of engineering components
Tensile residual stress is detrimental to the fatigue strength, corrosion resistance and crack resistance of welded joints [2,3,4]
The aim of this paper is to investigate the effect of the reheat temperature on the residual stress in multi-pass T-welded joints using low transformation temperature (LTT) welding wire

Summary

Introduction

It is well known that fusion welding has been applied to a large number of engineering components. The non-uniform temperature distribution and constraint during the welding process engender residual stress in the welded joints [1]. Tensile residual stress is detrimental to the fatigue strength, corrosion resistance and crack resistance of welded joints [2,3,4]. In order to minimize these adverse effects, it is necessary to take appropriate measures, such as ultrasonic peening [5], TIG dressing [6], local heat treatment [7] and so on. These post-weld treatments are costly and time consuming.

Objectives

Methods

Results