A PSEUDO-INHERITANCE OF FRACTURE OF ALLOY STRUCTURAL STEEL

Such inheritance of fracture is a pseudo-inheritance of fracture if the quenching structure, overheated not too seriously, of the alloy structural steel 40CrNi underwent requenching from normal quenching temperature reheating up at medium rate. This coarse grain fracture, showing one of the priorly overheated coarse austenite grain, is, in reality, fine grain fracture along fine equiaxial austenite grain boundary formed on reheating at medium rate. So it is called the pseudo-inheritance of fracture. It seems to be not affected on the impact toughness. The origin of pseudo-inheritance of fracture has been discussed.