Method for manufacturing massive steel workpieces and workpieces thereby obtained.

摘要

A quenching treatment for attaining the desired characteristics in at least a part of the massive block or piece is defined. The rates of cooling VRC and VRP of the block at the core and at the skin during the quenching are determined. The block is made of a steel whose chemical composition has been adjusted so as to obtain a martensitic structure at the core under the effect of deformations induced by the quenching, although the rate of cooling at the core VRC of the block or piece is lower than the critical rate of martensitic transformation. Appropriate tempering is performed after the quenching. The blocks or pieces exhibit high tensile mechanical characteristics and good tenacity at all points and are weldable. The process makes it possible to define a class of steels satisfying the conditions imposed by the quenching and exhibiting a minimum equivalent carbon. <IMAGE>