Abstract: Aiming at the leakage problem of alloy 825 heat exchange tube in high heat gas steam generator during its application, this paper performed finite element analysis on the expansion structure of the adhesion expansion and then provided the recommended expansion pressure for adhesion expansion. Taking the seam corrosion factors into account, the expanded joint structure of slotted expansion was designed. And through simulation and analysis, the proper expansion pressure and the degree of expansion were presented. These can provide reference for the expansion process of alloy 825 heat exchange tube.

Key words: alloy 825 heat exchange tube, expanded joint structure, slotted expansion, adhesion expansion, expansion pressure, degree of expansion