On the basis of the two-dimensional cellular automaton model, a three-dimensional cellular automaton model of austenitizing process was established. By considering the orientation of pearlite layer and the direction of austenite grain growth, the velocity of the interface was calculated during the austenitizing process. The austenitizing process of GCr15 steel was simulated, and the anisotropy of grain growth rate during austenitization was demonstrated by simulation results. By comparing the simulation results with the experimental data, it was found that the calculated results of the three-dimensional cellular automaton model established in this paper were in good agreement with the experimental results. By using this model, the three-dimensional austenitizing process of GCr15 steel at different temperatures and under different processing times can be analyzed, and the degree of austenitization can be predicted.

In bearing applications, the development of new materials has become a focus of scientific research in order to make bearing systems smaller and rotate more accurately. Bulk metallic glass (BMG), which has high strength, stiffness and resistance to corrosion, is becoming a promising candidate for bearing and shaft materials. When used as shafts, the friction feature of BMG needs to be evaluated comprehensively. In this work, the friction and wear properties of Ni-based, Zr-based, and Cu-based BMGs sliding against brass lubricated with lithium grease were investigated, using traditional bearing materials (GCr15 steel) as comparison. The results showed that the wear mechanism of the BMGs was primarily abrasive, supplemented by an adhesive wear behavior when sliding against brass plates, just like GCr15 steel. The wear loss of the friction pair (brass plates) increases when the applied normal load increases and the sliding speed decreases. Compared with GCr15 steel, BMGs exhibit better friction performance at low sliding speed, and Ni-based BMG always exhibits a smaller wear loss, especially under large load and low sliding speed. The wear loss of brass plates against Ni-based BMG pin is 24.3% lower than that against GCr15 steel under an applied load of 10 kg, which indicates that Ni-based BMG is an attractive bearing and shaft material for industrial application.

In order to improve the tribological performance of the slanted guide pillar, Cu particle reinforced composite coatings were synthesized on the surface of GCr15 steel using the plasma transferred arc (PTA) alloying technique. A systematic experimental investigation was conducted to study the effects of PTA current on the microstructure and microhardness of alloyed coatings. In addition, tribological behaviors at room temperature (RT) and high temperature (HT) were investigated. The results indicate that at low PTA current (70A), due to the insufficient current, no Cu particles are dissolved in the alloyed coating and a Cu-rich layer is observed on the surface. With the increase in the PTA current, Cu particles are gradually dissolved into the alloyed layer and the microstructure of alloyed coating mainly consists of bamboo-like martensite, retained austenite, and dispersed Cu particles. The microhardness of the PTA samples is approximately four times that of the untreated sample. The tribological results exhibit that an abrasive wear at RT and slight abrasive wear with oxidation wear at HT are the dominant wear mechanisms of alloyed coatings. The PTA samples show far superior antifriction properties compared to the untreated and remolten samples at both RT and HT, which can be attributed to the formation of lubricating Cu films and the improvement in microhardness.