Effect of Different Lap Angles on Corrosion Resistance of SUS304 Stainless Steel Joints Welded by TIG Welding

Abstract

High-quality welded structure products can be obtained by formulating a reasonable welding process. However, serious corrosion problems can still occur in the process of use, especially in the use of thin stainless steel lap structures. In this paper, the influence of different lap angles on the corrosion resistance of the joints was analyzed. The experimental results revealed that the heat input during the welding process of different lap joints was basically the same, so the difference in microstructure was not significant. The distribution pattern of microhardness was also consistent, and the hardness of the lap joint was high in the weld zone, low in the heat-affected zone and fusion zone. The effect of joint angle on corrosion resistance was obvious. With the increase of the lap angle, the overall corrosion resistance presented a tendency to first increase and then decrease.The corrosion resistance of the joint was excellent when the lap angle was 18°, the self-corrosion current density was the minimum of 2.528 × 10⁻⁶ A cm⁻² and the charge transfer resistance R_p was the maximum of 3516 Ω cm². The corrosion resistance of the welded joint was poor when the lap angle was 27°, the self-corrosion current density was the maximum of 1.151 × 10^–5 A cm⁻² and the charge transfer resistance R_p was the minimum of 840.7 Ω cm².