Study on strength properties of butt-welded joints with stainless and carbon steel

Steel bridges are generally made of carbon mild steel for economic reasons, and repainting is used as an anticorrosion method. Therefore, the cost of repainting is a problem of their life cycle. However, the corrosion of steel, which is the reason for repainting, often progresses at specific parts such as the ends of girders, and corrosion hardly ever progresses uniformly throughout the steel bridge. As a countermeasure, the authors have proposed using stainless steel with high corrosion resistance for steel bridges. However, stainless steel has a high material cost, and if a steel bridge is constructed entirely of stainless steel, increasing cost will be an issue. We are therefore developing a hybrid bridge of carbon mild steel and stainless steel using stainless steel only at the end of girders where corrosion of steel is a problem. This paper reports the results of various tests aimed at verifying the tensile strength properties and fatigue strength of steel plates butt-welded with stainless steel and carbon mild steel.