Session: DA-04-01 Inelastic, Nonlinear, and Limit Load Analysis

Paper Number: 62109

Start Time: Tuesday, July 13, 2021, 08:00 PM

62109 - A New Approach for Weld Creep Lifetime Assessment Based on Local Property Measurement 

A New Approach for Weld Creep Lifetime Assessment based on Local Property Measurement

Wei Zhang^{a, *}, Yiyu Wang^a, Yanli Wang^a, Zhili Feng^{a, *}

^aMaterials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA

Corresponding author. Wei Zhang: zhangw4@ornl.gov; Zhili Feng: fengz@ornl.gov

A new engineering assessment approach is presented to predict the creep deformation and rupture life of Grade 91 steel weldments based on the experimentally determined local properties of heat affected zone (HAZ). As the service life of welded components of creep-resistant steels is usually limited by the premature failure in the narrow inhomogeneous HAZ, it is crucial to use the local and heterogeneous properties in HAZ for reliable evaluation and prediction of the rupture behavior. A cavity-evolution based creep model was developed to simulate the local creep deformation and damage behavior of Grade 91 welds, using the experimentally measured local properties.  The approach was applied to analyze the creep deformation and rupture life of Grade 91 steel weldments, which shows a good agreement with the experiment measurement over a wide range of applied temperature and stress conditions. Furthermore, the proposed approach provided quantitative remaining life prediction for an after-service 9% Cr steel weldment (>100,000 service hours) by including the specific aspects regarding the effects of pre-existing damages which developed and accumulated during long-term services. The present work established an effective engineering approach for remaining life assessment of creep-resistant steel weldments.

Presenting Author: WEI ZHANG Oak Ridge National Laboratory

Authors:

WEI ZHANG Oak Ridge National Laboratory
Yiyu Wang Oak Ridge National Laboratory
Yanli Wang Oak Ridge National Laboratory
Zhili Feng Oak Ridge National Laboratory