Special features of the formation of the structure and properties in heat treatment of large preforms of structural steels

Steels for large-size parts should provide uninterrupted and reliable operation of them at positive and negative temperatures of the ambient. Traditional methods for obtaining a set of high properties in large preforms are well known. Steels used for these purposes are alloyed with up to 3% Ni and 0.5% Mo. The high cost of these alloying elements has led to the development of economically alloyed steels with elevated strength and reduced capacity for brittle fracture. A computational method for choosing the materials for large-size forgings and castings is presented.