Investigation of the Transformation of the Structure and Properties of Heredity of Thermofrictional Hardening of Steel Under Conditions of Elevated Temperatures

Abstract

Thermofriction hardening of steels is a modern technology for extended use in the production of various parts, the surfaces of which require increased wear resistance. The presented research continues the work of the authors on the study of the transformation and properties of metal structures that have received frictional processing; identification of physical mechanisms of steel hardening and the formation of ideas about residual manifestations and support of the strength heredity of intense frictional contact in the subsequent life cycle of the part at the final operations of its shaping and operation under conditions of thermophysical loading similar to tempering. This study examines the behavior of surfaces hardened by thermofrictional treatment under conditions of subsequent operational thermal loading, which is simulated by heating to elevated temperatures (up to 600 °C) and holding steel at these temperatures for up to one and a half hours. Metallographic and durametric studies have been carried out on cross-sectional sections of 65G steel samples. The microhardness in the near-surface layer decreases the more, the higher the heating and the time of testing with an elevated temperature. At the same time, the surface of steel that has previously undergone thermofrictional hardening is much harder than its base in the entire range of experimental conditions. This indicates the prospects of thermofriction hardening for steel products operating under conditions of increased thermal loads, and stimulates further research in this direction.

Surface Roughness Modeling of Hard Turning 080A67 Steel

“…Some studies were carried out to evaluate the characteristics of this steel type such as evaluating the degree of deformation when hot rolling [3], and evaluating friction coefficient [4]. Many studies have been carried out to improve the advantages of this type of steel, such as improving wear resistance by the heat treatment method [5][6][7][8], improving compressive residual stress in magnetic processing [9], developing technical solutions to produce high-quality products from the casting process [10], investigation of solutions to reduce microcracking on the surface [11], studies on the solutions to increase the hardness of the surface [12][13], etc. This type of steel is increasingly used to manufacture parts with high-quality requirements, which usually need some finished faces to assemble with other parts.…”

Selection and Application of the Optimal Surface Engineering Method to Restore the Properties of Rolling Equipment Elements that Have Been Reduced Due to Violations of Surface Grinding Technology

“…This approach can be realized by using various methods to influence the structural condition of the product surface. The use of, for example, the TFS technology [1,3,6] or other methods of surface hardening is quite possible to solve such problems. However, the feasibility of using a particular treatment method is determined by the ability to achieve the required properties while minimizing costs and meeting the requirements for each specific hardening object.…”