Effect of brazing residual stress on creep for stainless steel plate-fin structure

The effect of residual stress on creep for microminiaturized nickel base brazed stainless steel plate-fin structure was analyzed by finite element method with ABAQUS code. The results show that because of mismatch of mechanical properties between filler metal and base metal, the welding residual stress was generated inevitably, which has great influence on the creep deformation and life. The residual stress can not be ignored in the strength design and should be controlled during the manufacture of plate-fin structure. The stress and strain is concentrated in the fillet where the creep crack will initiate, propagate and result in the failure. The strain and stress in plate is larger than that in fin, so the cracking susceptibility of plate is lager than that of fin. The present work provides a reference for strength design at high temperature for plate-fin structure.