Paper Title:

Effect of Prestrain on Fracture Toughness of Welded Joint

Periodical Applied Mechanics and Materials (Volumes 29 - 32)
Main Theme Applied Mechanics And Mechanical Engineering
Edited by Honghua Tan
Pages 1441-1446
DOI 10.4028/www.scientific.net/AMM.29-32.1441
Citation Qing Hua Lu et al., 2010, Applied Mechanics and Materials, 29-32, 1441
Online since August, 2010
Authors Qing Hua Lu, Zhi Shui Yu, Li Gong Chen
Keywords Crack Tip Opening Displacement (CTOD), Impact Toughness, Prestrain
Price US$ 28,-
Article Preview
View full size
Abstract

The tension, Charpy notch impact and fracture toughness tests on structural steels Q235B and Q345 were carried out under different prestrains. Ductile to brittle transition curves are investigated using Charpy impact tests. The results indicate that the prestrain decreases the impact toughness of both base metal (BM) and weld metal (WM); and increases the ductile-brittle transition temperature as well as the risk of fracture. The prestrain is also found to have a more significant effect in a less ductile material. River marking, the characteristic of cleavage fracture, is observed in the Q235B WM specimens 10% prestrain conditions at 0℃. The fracture surfaces of Q345 WM specimens are characterized by dimple-like structures. The depth of these dimples is decreased under prestrain applied before welding. The CTOD-prestrain curves are obtained using Boltzmann relation.