Effect of austenitic fillers on microstructural and mechanical properties of ultra-low nickel austenitic stainless steel

In the present investigation effect of austenitic fillers namely E308, E309 and E310 on microstructural and mechanical properties of ultra-low nickel austenitic stainless steel weldment was analysed. The WRC-1992 diagram has been used to predict delta-ferrite and solidification mode of weld metal. Microstructural exploration confers the variation in magnitude and morphologies of delta-ferrite for different Cr-eq/Ni-eq ratio. It was observed that greater amount of delta-ferrite resulted in improved tensile strength. On the other hand, it lowered the impact strength of weld joint. The results indicated that E308 exhibits higher hardness and tensile strength, whereas E310 demonstrates higher impact strength and this may be attributed to the variation in delta-ferrite content and solidification mode. During tensile test joints failed in heat affected zone for all weld specimen. Surface morphology of fragmented specimens was analysed using scanning electron microscopy and different morphologies were recognised for samples failed before and after Strauss test.