Reheat cracking has been widely studied for steels used for nuclear, chemical and petrochemical pressure vessels. One particular problem restricting the use of these steels is the formation of cracks in the coarse grained HAZ during reheating. Such cracks appear in the overheated HAZ during welding or during the stress relief heat treatments.
It appears thus necessary to determine the facts responsible for this new problem.
Materials will be quenched and tempered steels with yield strengths above 500 MPa and thickness above 20mm.