TWI Industrial Member Report Summary 484/1993
By B J Ginn
Components manufactured from austenitic stainless steel are initially more expensive than comparable items manufactured from carbon steel. However, the increased production costs can, in some cases, be recouped by improved component corrosion resistance and hence a longer service life. Such savings could contribute to a reduction in losses through corrosion which viewed nationally for the UK alone probably exceed £1x109 per annum.
In recent years, interest has developed in the 'low cost stainless steels' - in particular in the low C, 12%Cr ferritic:martensitic types. Doubts exist though, as a legacy from the early Ti stabilised grades produced in the 1970s, concerning reduced weld HAZ toughness, increased HAZ hardness and possible notch sensitivity.
Previous work at TWI has examined the conventional arc welding of commercial alloys. However, no data exist on other processes which may offer a higher melt joint completion rate. This report describes an investigation into the weldability of three commercially available 12%Cr ferritic:martensitic stainless steels using electron beam and linear friction welding, together with comparative MMA welding.