Evaluation of tool material performance for the friction stir welding of 6mm AISI 304L stainless steel

TWI Industrial Member Report Summary 915/2008

By J Perrett

Background

Friction stir welding (FSW) is a solid-state joining process invented and patented by TWI in 1991. The majority of process development work to date has focused on the joining of low-softening temperature alloys such as aluminium, magnesium and copper. Due to the wide range of industrial applications across many industry sectors, the process is now regarded as relatively mature for these materials. Friction stir welding for higher temperature materials (eg steels) is not yet a mature process and significant work is ongoing in this area.

This report summarises work performed on the evaluation of tool materials for the FSW of 6mm thickness AISI 304L stainless steel. The aim of this work was to assess, test and compare the leading candidate tool materials for FSW of high-softening temperature materials, and to provide a benchmark for the performance of these materials against which to measure future progress.

Objective

Assess, compare and set a benchmark for the performance of the current front-running tool materials for the FSW of 6mm thickness AISI 304L stainless steel using appropriate comparative tests.