О возможности повышения износостойкости быстроизнашиваемых элементов горно-обогатительного оборудования термомеханической обработкой

Abstract

Hadfield steel (110G13L) is the basic material for fast wornout items of mining equipment: beaters, hammers, liners, refractory plates of crushers and mills. By way of example, the effect of cold hardening was specifically analyzed on the rate of wear of mining equipment parts for various types of wear by hard (more than 1100 HV) and soft rock. A unique ability of that steel to resist shock wear is noted. It is shown that this steel exhibits low resistance to abrasive rock wear. Meanwhile wear by rock of hardness lower than steel (less than 1100 HV), may be substantially increased by pre-hardening of samples (up to 10-fold). In case of wear by high hardness rocks, shock impact that should contribute to hardening of the material, fails to increase abrasive wear resistance of Hadfield steel, and in that parameter it does not differ from the conventional medium carbon steel 45. Also, the authors of this article describe a technique they developed of high-temperature thermomechanical treatment of specimen of Hadfield steel (free forging at 1150-950oC and subsequent quenching in water) and experiments in their abrasion. The results of tests show that hardness and wear resistance of Hadfield steel to hard abrasive (corundum 25A with aggregate hardness of ~2500 HV) increases with plastic deformation at HTMT. For maximum plastic deformation intensity (deformation magnitude of α = 2.25), reached in the experiments by the authors, wear resistance grew by 70% as compared to undeformed steel. The dependence is presented of wear resistance of steel on hardness, HV, achieved in the result of plastic deformation. Since a similar positive effect was obtained earlier by the authors for 35HGSA steel, also used in mining machinery, they conclude that the HTMT technique may be recommended for treating short lived parts of the mining and mineral processing equipment to increase their service life.