Experimental investigation on brazing residual stress distribution in 304 L stainless steel core plate

Abstract

Stainless steel core plate (SSCP) is a novel structural element. It consists of two stainless-steel panels and a quantity of stainless-steel core tubes, which are brazed by elevated temperature inert gas. The brazing residual stress (BRS) in weld seam is very important for mechanisms of SSCP during exterior loading. In this study, the magnitudes and distributions of BRS in SSCP have been comprehensively investigated by experiments. The surface BRSs of 35 specimens were measured by both hole-drilling (HD) and X-ray diffraction (XRD) methods. Based on the experimental results, the BRS distribution of the single unit of SSCP shows symmetry along with the axis of the core tube. The peak tensile BRSs mainly occur at the area near the brazing joint. The values of peak tensile BRSs in panels and core tubes even reach to 59.6% and 54.1% of the nominal yield strength, respectively. A simplified predictive model for BRS distribution in the single unit of SSCP is proposed accordingly. The applicability of the proposed model is verified by the nine-unit specimens of SSCP. This investigation enlarges the applicability of the HD and XRD methods for further research in stainless steel core plate. Moreover, the proposed model can be adopted for theoretical analysis and numerical simulations of the SSCP subjected to exterior loads.