Finite Element Analysis of the Effect of Brazed Residual Stress on Creep for Stainless Steel Plate-Fin Structure

Abstract

This paper presented a finite element analysis of the effect of brazed residual stress on creep for stainless steel plate-fin structure using finite element code ABAQUS. The as-brazed residual stress distribution generated during the brazing process was obtained. Two cases, which are denoted Cases 1 and 2, were analyzed and compared to discuss the effect of as-brazed residual stress on creep. Case 1 was to carry out creep analysis just at the internal operating pressure. Case 2 was to perform the creep analysis considering the internal operating pressure in conjunction with as-brazed residual stress. The results show that due to the mechanical property mismatch between filler metal and base metal, large residual stress is generated in the brazed joint, which has a great influence on creep for stainless steel plate-fin structure. The creep strain and stress distribution of the overall plate-fin structure is obtained. The position that is most likely to fail is the fillet for the plate-fin structure at high temperature. Especially in the fillet interface, the creep strain and stress distribution are discontinuous and uncoordinated, which have great effect on creep failure.