Influence of Thermoelectric Characteristics of High-speed Steels on Their Tribotechnical Properties

What is it about?

The purpose of the work is to predict the wear resistance of high-speed steels on the basis of structure-sensitive parameters: absolute (relative) thermal electromotive force of the tool material and thermal entropy, which can be calculated according to the additivity rule with a known chemical composition of the steel. The theoretical relationship between the change in the entropy of steels and their absolute thermal electromotive force has been experimentally confirmed, according to which a higher value of the entropy of the material corresponds to a lower value of the absolute electromotive force. The established dependence is valid for high-speed steels of a wide range of chemical compositions. In order to identify the relationship between entropy, as a thermodynamic characteristic of high-speed steels, and their wear resistance, tribological tests of cylindrical samples made of high-speed steels of various grades and durability studies of drills made of steels of the same grades when processing steel 45 were carried out. As a result of the tests, high-speed steels with high values of thermal entropy and minimal values of absolute (relative) thermal electromotive force showed the greatest wear resistance. The established connection between the wear resistance parameters of highspeed steels and their structurally sensitive characteristics at the micro level - entropy and absolute thermal electromotive force - will serve as a tool for predicting the performance properties of both existing and newly developed grades of highspeed steels. To reduce wear during friction and cutting, it is necessary to use grades of high-speed steels with a maximum value of thermal entropy and minimum absolute thermal electromotive forces.

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Photo by Johnny Sanchez on Unsplash

Photo by Johnny Sanchez on Unsplash

Why is it important?

Based on the results of thermoelectric studies, the theoretical relationship between the structure-sensitive characteristics of high-speed steels at the micro level - thermal entropy and absolute thermal electromotive force - has been confirmed. A connection has been experimentally established between the wear resistance of high-speed steels during friction and cutting and the magnitude of the absolute thermal electromotive force. Thus, to reduce the wear of high-speed steels during friction and cutting, it is necessary to use grades of high-speed steels with maximum values of thermal entropy and minimum ab-solute (relative) thermal electromotive force.

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