Experimental investigation of local tensile and fracture resistance behaviour of dissimilar metal weld joint: SA508 Gr.3 Cl.1 and SA312 Type 304LN

The aim of the paper is to evaluate the local tensile and fracture toughness properties of the dissimilar metal weld joints between SA508Gr.3 Cl.1 and SA312 Type 304LN pipe. Weld joints have been prepared by manual gas tungsten arc welding (GTAW) process with conventional V-groove and automatic hot wire gas tungsten arc welding with narrow gap using different filler wires/electrode such as Inconel 82/Inconel 182 and ER309L/ER308L. The tensile and fracture toughness test specimens have been machined from different regions of dissimilar metal weld such as heat affected zones, fusion lines, buttering layer, weld metal and both base metals. Tensile and fracture toughness tests have been carried out as per the ASTM standard E8 and E1820 respectively. Tensile and fracture toughness results of all the regions of dissimilar metal weld joints have been discussed in this paper. Metallurgical and fracture surface examinations have also been reported to substantiate the tensile and fracture toughness results. Need for the local properties for integrity assessment of the dissimilar metal weld joints has also been brought out.