Hydro-Abrasive Erosion Resistance of C45 Steel in Different Heat-Treated States on a Designed Wear Test Apparatus

In this study, the hydro-abrasive erosion behaviour of a C 45 steel in different heat-treated states, which are normalizing, oil-quenching, tempering after oil-quenching and boronizing thermochemical surface treatment, was investigated on a designed and manufactured hydro-abrasive wear test apparatus. Boronizing was performed in a solid medium consisting of B4C, SiC, and KBF4 at a temperature of 900 degrees C for two hours. The microstructure and the wear regions of the specimens were characterized using an optical and a scanning electron microscope. In the tribogical system, the specimens were rotated in a system instead subjecting them to a fluid and moving abrasive particles. The wear tests were performed under a fixed rotational speed of 53 rpm for each specimen in the respective heat-treated state. The weight loss at the end of each wear period of 10 hours was measured using a precision electronic balance with an accuracy of 1 mg. It was concluded from the investigation that oil-quenching and tempering treatments led to significant improvement of the hydro-abrasive erosion resistance, while as-boronized and as-normalized specimens exhibited the lowest erosion resistance. In spite of its high surface hardness in the boronized state, the C 45 steel did not affect positively its hydro-abrasive erosion resistance. In the as-normalized specimen, the low hydro-abrasive erosion resistance corresponded with a decrease of hardness. An increasing amount of ferrite and pearlite in the C 45 steel led to the reduction of the hydro-abrasive erosion resistance.