A novel approach to characterising the mechanical properties of supermartensitic 13 Cr stainless steel welds

Novel measurements of the tensile properties of the weld metal, heat-affected zone (HAZ) and parent plate of supermartensitic 13 Cr stainless steel welds have been made by taking sections from each region and testing with a miniaturised tensile testing machine. Measurements were made on welds produced with a super-duplex stainless steel and a matching filler. The tensile tests were conducted at various temperatures and emphasised the need to account for the temperature sensitivity of the mechanical properties of the individual regions while conducting 4-point bending on welded specimens. Scanning microhardness measurements were also made and significant sub-surface hotspots were highlighted, which could have been inadequately characterised by conventional line-scan measurements. Residual stress measurements on a specimen taken from a super 13 Cr weld with a super-duplex filler indicated local regions of high compressive stress, up to 350 MPa in magnitude. This needs to be taken into account while interpreting the hardness results.