TWI Industrial Member Report Summary 117/1980
By J Honeycombe and T G Gooch
A study has been carried out of the mechanical properties developed in welds in stress corrosion resistant ferritic stainless steel. Material from 2-9mm thickness was welded using the MMA, MIG and TIG processes with matching and non-matching composition consumables. Tensile, bend and toughness tests were carried out, the last named involving both Charpy V-notch impact and fatigue precracked fracture mechanics specimen methods.
Weld tensile strengths were lowest with matching composition consumables, but in all cases test welds exceeded typical parent material specification minima. Generally satisfactory bend test behaviour was noted. Welding was found to promote severe embrittlement in the HAZ in consequence of grain growth, with the result that, in all materials, the ductile brittle transition temperature for the HAZ was above room temperature. Toughness of matching composition deposits was lower than that of the HAZ, considerably higher results being obtained in non-matching deposits containing appreciable amounts of austenite.