Assessment of the chemical composition of LTT fillers on residual stresses, microstructure, and mechanical properties of 410 AISI welded joints

Abstract

The present paper aims to characterize the welding residual stresses, microstructure, and mechanical properties of some AISI 410 plates welded with low-transformation temperature (LTT) fillers containing different Ni wt.%. The LTT fillers with 11 wt.% Cr and Ni content varying between 3 and 11 wt.% were produced using an arc melting furnace. Effect of Ni wt.% on Ms of LTT fillers was studied using a dilatometer. Five-millimeter-thick AISI 410 plates were welded by GTAW using LTT fillers mentioned above and ER410 conventional filler as a reference. Welding residual stresses were measured by using the hole drilling strain gage method (HDSG). Analyzing the effect of welding dilution on the chemical composition of weld metal was carried out using energy-dispersive X-ray spectroscopy (EDS) followed by a dilatometric test for the evaluation of weld metals Ms after welding. Microstructural examinations show that conventional filler leads to ferritic–martensitic weld metal while in the cases welded with LTT fillers, delta ferrite (δ-ferrite) is decreased when Ni increases. Also, by increasing Ni more than 9 wt.%, the retained austenite is detected in the weld metal. Furthermore, weld metal hardness rises with increasing Ni. Performing tensile and impact tests on welded joints endorse the successful use of LTT fillers for welding the AISI 410 plates.