NUMERICAL AND EXPERIMENTAL INVESTIGATION OF THE EFFECT OF HYDROSTATIC PRESSURE ON THE RESIDUAL STRESS IN BOILER-TUBE WELDS

作者：Danyali Daryoush; Ranjbarnodeh Eslam^*

来源：Materiali in Tehnologije, 2016, 50(5): 775-782.

DOI：10.17222/mit.2015.255

• hydrostatic test
• residual stress
• boiler tubes
• tube-sheet
• finite element method (FEM)

A tube to tube-sheet weld joint is a critical section in many boilers. Leakage and failure are two common problems that can occur with this type of joint. The tensile residual stresses associated with welding can play a major role in these problems. In the present study, the Finite-Element Method is used to predict the residual stresses in a tube to tube-sheet weld and the effect of hydrostatic pressure on the residual stresses' redistribution. Investigations were performed by numerical analyses and experimental methods. The joint included a circumferential fillet weld in one pass using a gas tungsten arc welding process. The thermomechanical behavior of the joint is simulated with a two-dimensional axisymmetric model and a subroutine developed in ANSYS software. The thermography method is used for the thermal verification and the hole-drilling strain gauge under post-weld heat treatment is used for the mechanical analysis verification. The numerical and experimental results showed that applied hydrostatic pressure can reduce, by about 58 %, the axial residual stress.

• 出版日期2016-10