Study on impact wear properties and mechanism of new lightweight austenitic wear-resistant steel

    
    Introduction
    
    Recently, with the rapid development of modern industry, the requirements for wear resistance of material components have been increasing constantly. Austenitic wear-resistant steels have attracted much attention due to their wear resistance and machinability. But the traditional austenitic wear-resistant steels are usually heavy and do not accurately meet the need of economic and light construction designs. Therefore, a new lightweight austenitic wear-resistant steel has been developed to solve these problems. This article investigates the impact wear properties and mechanism of this new lightweight austenitic wear-resistant steel.
    
    Properties
    
    The new lightweight austenitic wear-resistant steel is an austenitic stainless steel made with a certain composition. The composition enables its matrix to retain austenitic structure at room temperature and starts to transform to martensite at the temperature of 475°C. In addition to its lightweight and wear resistance, compared to the traditional austenitic wear-resistant steels, this steel has lower work hardening, higher toughness and elongation.
    
    Impact wear experimental testing
    
    The impact wear properties of the new lightweight austenitic wear-resistant steel were investigated using Pin-on-Disk testing apparatus. The impact wear test was conducted at a normal load of 100 N and a sliding velocity of 55 mm/s under dry and water lubricated conditions. The sliding distance was 60000 cycles and the wear loss of the samples were measured before and after the test to calculate the wear rate.
    
    Figure 1: Pin-on-Disk testing apparatus
    
    Results and Discussion
    
    The experimental results showed that the wear rate of the new lightweight austenitic wear-resistant steel was lower compared to traditional austenitic wear-resistant steels under dry as well as water lubrication conditions. The wear rate of the steel decreased with increasing sliding distance. The wear rate was also lower in water lubrication conditions compared to dry conditions.
    
    Analysis of the worn surfaces under Scanning Electron Microscope (SEM) showed that the wear mechanism is mainly abrasion and the role of adhesion and abrasive wear decreased gradually with the increase of impact energy. From the results of X-ray diffraction (XRD) analysis, it was found that the martensite content increased with increasing sliding distance. This indicates that martensitic transformation is an important wear protection mechanism of the new lightweight austenitic wear-resistant steel.
    
    Conclusion
    
    The new lightweight austenitic wear-resistant steel has good impact wear properties, with the wear rate lower than that of traditional austenitic wear-resistant steels. The wear mechanism of the steel is mainly abrasion and the martensitic transformation plays an important role in wear protection. The steel is thus suitable for use in light construction designs and applications.

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