Typically, the fracture toughness of welded joints are evaluated using Charpy-V tests. This method has been sufficient for traditional steels, which obey Charpy-T0 correlation. In recent years ultra-high-strength steel (UHSS) has come to market in which the Charpy correlation is not reliable.
To validate the weld toughness of two different types of UHSS, fracture tests were performed according to ASTM procedures on different portions of weld and heat affected zones (HAZ) as well as the base material.
The results show that when using the proper heat input during welding the fracture toughness is appropriate in the weld area. Naturally these results are valid only for the tested steel grades and cannot be used with other UHSS products.