INVESTIGATION OF THE INFLUENCE OF BORIDING WITH RARE EARTH ELEMENTS ON THE PROPERTIES OF H13 DIE STEEL

10.25712/ASTU.1811-1416.2022.03.011

Abstract

In this paper, rare earth boronizing is carried out on bearing forging dies to study the effect of rare earth on the structure and properties of boronizing layer, analyze and compare the layer microstructure, microhardness, brittleness, high temperature oxidation resistance and wear resistance of original sample, single boronizing and rare earth boronizing samples. The results show that after rare earth boronizing, the structure of the bearing forging die becomes more compact and uniform. The highest hardness is up to 1612.69 HV (at the position of 60 μm from the boronizing layer surface). The brittleness is reduced. In the 60min friction and wear test, the weight loss of the rare earth boronizing sample is only 1/4 of the original sample, and 2/5 of the weight loss of the single boronizing sample, while the friction coefficient is maintained at about 0.23. At a high temperature of 800 °C, the oxidative weight gain of rare earth boronizing is only 68 % of the original sample. It can be concluded that the rare earth boronizing process can improve the structure of boronizing layer, the high temperature oxidation resistance and wear resistance of the bearing forging die surface, and reduce its brittleness.