Cruciform Fillet Welded Joint Fatigue Strength Improvements by Weld Metal Phase Transformations

Published

October 17, 2007

Author(s)

Philippe P. Darcis, H. Katsumoto, M C. Payares-Asprino, S. Liu, Thomas A. Siewert

Abstract

Arc welding typically generates residual tensile stresses in welded joints, leading to deteriorated fatigue performance of these joints. Volume expansion of the weld metal at high temperatures followed by contraction during cooling induces a local tensile residual stress state. A new type of welding wire capable of inducing a local compressive residual stress state by means of controlled martensitic transformation at relatively low temperatures has been studied, and the effects of the transformation temperature and residual stresses on fatigue strength is discussed. In this study, several LTTW (Low Transformation-Temperature Welding) wires have been developed and investigated to better characterize the effect of phase transformation on residual stress management in welded joints. Non-load-carrying cruciform fillet welded joints were prepared for measurement of residual stresses and fatigue testing. The measurement of the residual stresses of the three designed wires reveals a compressive residual stress near the weld toe. The fatigue properties of the new wires are enhanced compared to a commercially available wire.

Citation

Fatigue & Fracture of Engineering Materials & Structures

Volume

31

Pub Type

Journals

Keywords

fatigue, residual stress, weld metal phase transformations, welded joints

Citation

Darcis, P. , Katsumoto, H. , Payares-Asprino, M. , Liu, S. and Siewert, T. (2007), Cruciform Fillet Welded Joint Fatigue Strength Improvements by Weld Metal Phase Transformations, Fatigue & Fracture of Engineering Materials & Structures (Accessed April 26, 2024)