600 MW Steam Generator Repair Program: Hydraulically Expanded Tube to Tubesheet Joints

Abstract

To avoid stress corrosion cracking, a method of producing tube to tubesheet joints with low residual stresses was sought. Hydraulic expansion was found to be an acceptable method. In this paper, the experimental and theoretical work done to determine these stresses is presented. The area of interest is the transition region between the expanded and unexpanded sections of tubing. X-ray diffraction, stress corrosion cracking test and strain gauging were the prime measuring techniques used. Extensive use of finite element analysis was also made. In addition, the pull strength, length change, etc., of this type of joint were investigated.