ON THE CLASSIFICATION OF COLD RESISTANT MATERIALS

Low-temperature technologies are increasingly used in various industries. Cold-resistant materials have gained particular popularity in the field of creating low-temperature machinery. The need for a special approach when choosing cold-resistant materials used in the production of machines, equipment and structures, whose operation is carried out under extreme conditions [low temperatures, dynamic/static loads and (or) intense wear], caused the need to systematize them according to a complex of mechanical properties. Despite the fact that a wide variety of products is produced from new cold-resistant materials in Russia and abroad, neither the scientific literature nor the regulatory documentation provides a common unified classification, which covers a wide range of their categories. Research was carried out for shipbuilding cold-resistant steels, which is reflected in the Russian National Standard R 52927–2008 “Steel rolled for shipbuilding from normal, increased and high strength steel”, however, this classification is incomplete and covers strength categories from 265 to 735 MPa. This article presents comprehensive systematization of scientific data of new structural cold-resistant steels of various leading industries of strength category up to 1550 MPa with corresponding characteristics of plasticity and cold resistance. The article considers and summarizes various criteria used to classify cold-resistant materials, as well as preferred classification features, determines numerical ranges of constituent properties. The article develops a classification system of structural steels according to groups of strength, cold resistance and hardness. The use of the proposed classification of structural alloys makes it possible to select material of certain category (class) of strength depending on operational loads of structural elements, machines and equipment of leading industries in conditions of low temperatures, and also to predict their reliability life depending on interval of low-temperature operating threshold