Basic Concepts of the Optimal Mechanical Properties’ Complex for Protection of the Structural Steels against Embrittlement
Within the framework of the concept of structural suitability of metals and alloys, a physically grounded system of interrelation between the complex of mechanical properties «plasticity - strength - deformation endurance» and principles of rational formation of these properties for structural steels was developed. The main regularities of such a connection between properties and causes that regulate both the nature of their changes and the degree of sensitivity of some of the basic characteristics of a metal to a change in others are established. A comparative assessment of the strength reserves of structural steels on their ability to resist brittle fracture using the Kms mechanical stability index and embrittlement using the deformation endurance (break resistance) Br index was performed. Concepts about the quality of structural steels are formulated as a measure of their ability to resist embrittlement. A new «indicator» of the quality of structural steels is proposed: a measure of mechanical quality according to the deformation endurance Br for a given value of strength σY, reflecting their resistance to embrittlement.