Correlation of microstructure and fracture properties in weld heat- affected zones of thermomechanically controlled processed steels |
| |
Authors: | Sunghak Lee Byung Chun Kim DONGIL Kwon |
| |
Affiliation: | (1) Department of Materials Science and Engineering, Pohang Institute of Science and Technology, 790600 Pohang, Korea;(2) Iron and Steel Division of the Research Institute of Industrial Science and Technology, USA;(3) Department of Materials Science and Engineering, Changwon National University, 641-773 Changwon, Korea |
| |
Abstract: | This article presents a correlation study between the microstructural parameters and fracture properties in the weld heat-affected
zones (HAZs) of high-strength low alloy (HSLA) steels,i.e., a normalized steel and four thermomechanically controlled processed (TMCP) steels. The influence of the local brittle zone
(LBZ) on toughness was investigated by means of simulated HAZ tests as well as welded joint tests. The intercritically reheated
coarse-grained HAZ ex-hibited the lowest impact energy over the testing temperature range, indicating that this region was
the LBZ. By comparing the volume fraction of martensite islands with impact energy val-ues, this LBZ was attributed mainly
to the significant increase in the amount of martensite. Niobium was also found to have a deleterious effect on the HAZ fracture
toughness because of martensite hardening. This suggests that the formation of martensite islands must be controlled by proper
design of chemical compositions to reduce the carbon equivalent and by using the proper welding conditions to limit cooling
rates in order to optimize the fracture toughness of welded joints of TMCP steels. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|