Study On The Diffusion Model Of Vanadium In High Manganese Steel And The Influence Of Material Properties

High manganese steel is widely used for its advantages such as good toughness, able to withstand strong extrusion and impact, and nice wear resistance due to work hardening under extrusion and impact. However, the wear resistant property under low stress or low impact load environment is much lower due to that the high manganese steel does’t have high hardness hard point. Alloying high manganese steel and modification treatment were applied to improve the wear resistance of the high manganese steel under low stress or low impact load environment in the past. Although many machine parts require good surface wear resistance and good internal toughness, homogeneous wear resistant material by adding strengthening phase alloy elements to high manganese steel has higher hardness and less toughness at the same time. Functionally gradient materials (FGM) provide effective solution for this matter. In this study, improved capillary-bath method and combined type melting and diffusion process are used to investigate the diffusion mechanism of Vanadium in high manganese steel and establish the diffusion model of Vanadium atom for the purpose of getting Vanadium strengthening of high manganese steels gradient wear-resistant material and improving the wear resistance of high manganese steels under low stress or low impact load environment.This study adopts improved capillary-bath method to make diffusion test and the diffusion mechanism of Vanadium in high manganese steel. Combing Fick’s second law and alloy element distribution equation, the diffusion coefficient is obtained. By analysing the concentration distribution of Vanadium in capillary, microstructure and properties of the test; it is found that diffusion coefficient, concentration distribution and microstructure and properties are in Gradient distribution in capillary by test analysis.Used internal diffusion method, based on the distribution equation of the alloy atom in liquid metal, which can get the gradient distribution of the alloy element, carbide, mechanical properties and mechanical properties of Hard surface after solidification and tough inner through the strengthening effect of alloy carbides. Technique, such as electronic probe, XRD, optical microscope, micro-hardness and macro hardness test, are applied to investigate the microstructure, phase structure, and analyze the alloy element distribution of metallurgical bonding layer and the material mechanical property changes. The results show that granular and blocky carbides homogeneously are distributed on the austenite matrix, and the vanadium carbide diffusion concentration and the amount of carbides are of gradient distribution inside from the outside to the inside of diffusion member, which make the hardness have the property of gradient distribution.Through studying the diffusion machanism, The diffusion modal of Vanadium is established, which can provide theoretical guidance for the design of gradient wear resistant metal material. Meanwhile, the gradient property of microstructure and hardness of the gradient wear resistant material is verified by the microstructure analysis and microhardness test, which proposes a new preparation method for the gradient wear resistant material.