Evaluation of cracking resistance of copper-bearing age hardening steel weldment

The weldability of a low-carbon copper-bearing age hardening steel was evaluated using cracking susceptibility calculation, HAZ maximum hardness measurement, and Y-groove cracking evaluation test. The results show that the hardenability characteristics and cold cracking susceptibility of the steel are very low. The results also indicate that a crack-free weldment can be obtained during the welding of this type of steel even at an ambient temperature as low as - 5 degrees C as well as in an absolute humidity lower than 4 000 Pa without any preheat treatment. A slight preheat treatment can prevent the joint from cracking when welding is carried out at lower ambient temperature or higher absolute humidity.