Excavator Wear-resisting Backing Off The Material Research

Wear is a common form of failure for mechanical products, which brings huge economicloss to society annually. Shovel tooth is one wear part with large consumption on excavator, andconsiderable number of shovel teeth need to be imported each year. The working condition isvery poor. It not only suffers serious particle attrition, but also withstands the shock load inmining process. Therefore, it has important practical significance to reduce economic losscausing by wear, which depend on the development of new wear-resistance materials toimprove the the service life of workpiece.In this paper, it designed12series chemical composition and put forward a complete set ofheat treatment process, which in order to meet the requirements of both good wear resistanceand toughness for the shovel teeth. It has found the best matching components and the optimalheat treatment process according to the related inspection and the theoretical analysis todifferent components of the experimental steel by heat treatment.The shovel teeth of experimentsteel obtained good comprehensive mechanical property, which means that the shovel teethprong hold excellent abrasive resistance and certain toughness, and tooth handle is of hightoughness and certain wear resistance.The results of the study show that, the hardness increasied gradually,and impact toughnessobviously drop down with the increases of carbon content.The hardness and impact toughnessincrease at first by a trend to decrease with the increase of manganese content.. The bestchemical ratio of experimental steel (wt%) was C:0.44, Si:1.8, Mn:1.5, Cr:1.0. The optimalheat treatment process was determineded, according to the microstructure of materials andstructure analysis, by adopting mechanical properties test, microscope and SEM, EDAX, TEMetc.testing method.The hardness of experimental steel can reach HRC30~HRC38, and impacttoughness values ak≥80J/cm2after normalization at900℃.The hardness can reach HRC48~HRC54, impact toughness can be up to45~70J/cm2after quenching at900℃for one hour andisothermal at290℃for30min and tempering at200℃for2hours. The wear test simulatingactual working conditions showed that experimental material wear and tear volume decreasedsignificantly compare with the factory active-duty shovel tooth material. The hardness of shovel teeth, which produced by the experimental steel, presented goodtransition change from the tip to handle after heat treatment, which ensured the optimization ofthe mechanical properties of the tooth pointed and tooth handle materials. The hardness in toothtop was HRC48~HRC54, middle part was HRC40~HRC45, tooth handle was HRC30~HRC38.It has achieved good results in the mining actual production by installed test for theexperimental steel shovel teeth; its working life increased40%to60%than that of the originalshovel teeth. It can replace the factory active-duty shovel teeth and be suitable for massproduction for low-costing and simple process.