Optimising welding conditions for TRIP steels

TWI Industrial Member Report Summary 798/2004 

Steve Shi and Steve Westgate seek to develop improved procedures for resistance spot welding

Background

TRIP (Transformation Induced Plasticity) steels have become of considerable interest in the automotive industry in recent years because of their exceptional combination of high strength and ductility. However, their high carbon content, coupled with fast weld cooling rates associated with resistance welding, leads to high hardness levels (up to 600HV) in the weldment.

Objectives

• To develop improved procedures for resistance spot welding of high strength TRIP steels
• To determine the relationship between the static properties of welds and process parameters
• To examine the effect of weld carbon reduction on weld hardening and static properties of welds