Study on Microstructure and Wear Properties of Low Alloy Wear-resistant Steel Plate NM600

    
    Abstract
    
    The microstructure and wear properties of low alloy wear-resistant steel plate NM600 were studied in this paper. The results showed that the wear resistance of the wear-resistant steel plate was the focus of the research. The microstructure of the steel plate was analyzed and its composition was tested, and the wear mechanisms of the wear-resistant steel plate were studied. Besides, a wear resistance test was also carried out by using a pin-on-disk wear testing machine to evaluate the performance of the low alloy wear-resistant steel plate NM600. The results showed that the wear-resistant steel plate showed a good wear resistance. The wear mechanisms of the wear-resistant steel plate also revealed that the wear resistance of the wear-resistant steel plate was mainly caused by adhesive wear and abrasive wear. Furthermore, analyses on the microstructure showed that the wear-resistant steel plate had excellent wear resistance by forming tough carbides and their compositions.
    
    Introduction
    
    Wear resistance is the ability of a material to resist abrasion and wear, which is an important property for the service life of mechanical parts. Wear-resistant steels are widely used in many major engineering fields, such as dredging operations, rock crushing, power plants, tractors and military equipment, due to its excellent wear resistance. Among these wear resistant steels, low alloy wear-resistant steel plate NM600 has good wear resistance performance in severe environments. In order to evaluate the wear resistance of the steel plate, it is necessary to study its microstructure, macroscopic structure and wear resistance properties.
    
    Structural Analysis
    
    The low alloy wear-resistant steel plate NM600 was composed of some alloy elements, including C(<0.20%), w(<0.60%), Mn(0.9%-1.6%), Si(<0.30%), P(<0.025%), S(<0.020%), Cr(1.5%-2.5%), Ni(<0.50%) and Cu(<0.30%), where C is Carbon, w is manganese, Si is Silicon, P is Phosphorus, S is Sulphur, Cr is Chromium, Ni is Nickel and Cu is Copper. The microstructure of the NM600 steel plate mainly contains martensite, bainite and carbides, which has high strength, good toughness and superior wear resistance in comparison with normal microstructure. The microstructure of the NM600 steel plate is shown in Fig.1.
    
    Fig.1. Microstructure of Wear-Resistant Steel Plate NM600
    
    Wear Mechanisms
    
    The wear mechanisms of materials depend on the material properties, load, lubrication and environment. According to the mechanism of wear, it can be divided into abrasive wear, adhesive wear, corrosion wear and fatigue wear. The NM600 wear-resistant steel plate is mainly subjected to abrasive wear and adhesive wear. Adhesive wear is caused by the interaction between the mating surfaces and the opposing environment. The wear debris particles are mainly composed of the material itself which is stuck on the contact surface. And abrasive wear is caused by the material and other hard particles strongly interacting between each other, breaking through the surface of the material. The wear debris particles are mainly composed of hard particles from outside.
    
    Test Results
    
    In order to evaluate the wear resistance of the NM600 wear-resistant steel plate, a wear resistance test was carried out by using a pin-on-disk wear testing machine. In the wear test, the NM600 wear-resistant steel plate and SAE 1045 steel plate were used, respectively, as the wear specimen. The test results showed that the NM600 steel plate has excellent wear resistance and outperformed the SAE 1045 steel plate. The results of the wear resistance test are shown in Fig. 2.
    
    Fig.2. Wear Resistance Test Results of NM600 Wear-Resistant Steel Plate
    
    Conclusion
    
    The microstructure, macroscopic structure and wear resistance properties of low alloy wear-resistant steel plate NM600 were studied in this paper. The results showed that the NM600 wear-resistant steel plate had excellent wear resistance. Its wear mechanisms were mainly caused by adhesive wear and abrasive wear. The microstructure analysis revealed that the excellent wear resistance of the NM600 wear-resistant steel plate was attributed to the formation of tough carbides and its composition. In addition, the wear resistance test further confirmed the good wear resistance performance of the NM600 wear-resistant steel plate.

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