A. Roshanghias, Sharif University of Technology, Tehran, MO, Iran; F. Malek, A. R. Khani, Tarbiat modares university, Tehran, Iran
The objective of this research was to obtain the suitable welding process for
D6a steel with respect to fracture mechanics.
In this study the effect of heat input, preheat temperature and postweld heat treatment on the fracture properties of the weld metal and HAZ of D6a steel were investigated.
Experimental investigations of toughness and crack resistance parameters through impact tests and COD fracture toughness tests of a high-strength, low-alloy steel (HSLA) and its welded joint, were performed on the parent metal, weld metal and HAZ
The results obtained showed that the Maximum toughness and crack resistance of the weld metal and HAZ was obtained in sample with preheat and post heat temperature up to 300°c and 500°,respectively.
Hardness and tensile examinations were in agreement to the fracture toughness results.
Summary: In order to gain the benefits of weldable high-strength steels in pressurized equipment applications, satisfactory toughness and crack
properties of the welded joint, both in the weld metal and the heat-affected –zone (HAZ), are required
