Improvement of service properties of L53 steel with thermal strengthening

Abstract

The production of domestic all-metal plowshares made of steel L53, in the current situation in the agriculture, requires new solutions aimed at increasing the resource without significant technological and economic costs. Potential opportunities in this respect lie in conducting the thermal strengthening of such steel. However, the well-known works on this issue do not give a definitive answer about the possibilities of L53 and the optimum mode of heat treatment in terms of ensuring abrasive wear resistance. Therefore, the aim of the presented investigations was to improve the service properties of steel L53 by thermal strengthening, expressed in increasing hardness and wear resistance. During the experiments, the experimental samples (steel L53) were subjected to heating from 720…870 °С within 20 °С and cooling in the water with the subsequent determination of hardness and abrasion resistance. The wear tests were implemented on the plant of its own design, which allows changing the experimental conditions within a wide range. The obtained results indicate that conducting thermal strengthening from temperatures 840…860 °С allows increasing the abrasive wear resistance of L53 steel by 2,5…3 times, which is connected with phase transformations and the formation of hardening structures. It has determined by the experiments that the rational parameters of the thermal strengthening regime, which make it possible to exclude such an additional operation as the abatement. Accordingly, the application of thermal strengthening to provide increased hardness and resistance to abrasive enviroment (especially with regard to plowshares) is a necessary technological operation in the production of parts of tillage tools made of steel L53.