Mechanical Properties Evaluation and Crack Propagation Behavior in Dissimilar Metal Welded Joints of 304 L Austenitic Stainless Steel and SA508 Low-Alloy Steel

Yuman Sun,Rehmat Bashir,Shuai Wang,He Xue,Jinxuan He,Shun Zhang,Fuqiang Yang,Raffaella Testoni

doi:10.1155/2022/3038397

Abstract

The material mechanical properties and crack propagation behavior of dissimilar metal welded joint (DMWJ) of pressurized water reactor (PWR) was investigated. In this research, the mechanical parameters of the cladding layer materials (304L-SA508) of the DMWJ in PWRs were obtained by the continuous indentation test. Simultaneously, the user-defined (USDFLD) subroutine in ABAQUS was used to establish the heterogeneous materials model of the welded joint. On this basis, the local crack propagation path of DMWJs has been discussed based on the extended finite element method (XFEM). The result indicated that the strength value at the fusion boundary line (FB line) is the largest, and the yield strength reaches 689 MPa. The yield stress values of the cladding metal (304 L) and base metal (SA508) are 371 MPa and 501 MPa, respectively. Affected by the material constraint effect of the DMWJ, the crack will propagate through the FB line when the initial crack is perpendicular to the FB line. And when the initial crack parallels the FB line, the crack will deviate from it. Meanwhile, the crack propagation length is smaller as the initial crack tip is closer to the FB line when the load condition is constant.

Highlights

Dissimilar metal welded joints (DMWJs) are widely used to connect different metal materials in many engineering structural components, such as reactor pressure vessels (RPV) and pipes [1,2,3]
Several studies have demonstrated that the mechanical properties in the heat-affected zone (HAZ) of DMWJs become complex, which extremely affects the structural integrity of critical components in pressurized water reactor (PWR) [11,12,13]
The critical equivalent strain energy release rates GIC, GIIC, and GIIIC reflect the fracture resistance of materials during crack propagation. e power law based on energy is involved in this research to the crack propagation after the crack initiates

Summary

Introduction

Dissimilar metal welded joints (DMWJs) are widely used to connect different metal materials in many engineering structural components, such as reactor pressure vessels (RPV) and pipes [1,2,3]. The mechanical properties such as yield strength σy and tensile strength σu of the cladding layer of the DMWJ in PWRs were obtained by the continuous indentation test. E results indicated that the work hardening mismatch influences the crack growth path It is an effective means for the numerical simulation of the crack propagation behavior in DMWJs based on the extended finite element method (XFEM). The local mechanical properties of the cladding layer of the DMWJ were obtained by continuous indentation test, and the heterogeneous material model of the DMWJ was established by the user-defined field (USDFLD) subroutine for numerical simulation test. The local crack propagation behavior in DMWJs has been discussed based on XFEM

Continuous Indentation Test

Calculation Model

Results and Discussion

Conclusions e main acquired results are summarized as follows: