STUDYING THE STRENGTH OF DISSIMILAR JOINTS OF AISI 430 AND 301 STAINLESS STEEL WELDED AT DIFFERENT WELDING PARAMETERS

Abstract

Investigating the best welding parameters for resistance spot welding joints between AISI 430 and AISI 301 stainless steels was the primary focus of this study. This research involved welding samples of these stainless steel types using various welding parameters. Ferritic stainless steel (AISI 430) and austenitic stainless steel (AISI 301) were subjected to resistance spot welding, and different welding conditions were applied to produce a range of samples. The study specifically analyzed the influence of the welding current (2.5, 3.1 and 3.7) kA and welding time (40, 70 and 100) ms on the joining capability of these stainless steels. To determine the best welding parameters, microhardness measurements and tensile-shear tests were performed on the welded materials. The results indicated that increasing the welding current and welding time led to an increase in the tensile load. The maximum tensile-shear load 2036 N was observed at 3.7 kA and 100 ms. However, after a salt spray test (48 and 96) h, a serious decrease in the tensile load from 2036 N to 750 was observed at the high current 3.7 kA and time (70 and 100) ms. At 3.1 kA and 70 ms before and after the salt test, its value remained relatively constant, and the corrosion resistance of the weld joint was at the best level. The microhardness of the heat-affected zone increased, reaching its maximum point (for 3.1 kA and 70 ms: 347.3 HV and for 3.1 kA 100 ms: 369 HV) in the fusion zone. Moreover, the increase in the welding time and current was associated with an increase in the nugget size. The maximum nugget size was 3.61 mm at 3.7 kA and 100 ms.