Study On Prediction Model Of Abrasive Wear Of Medium Carbon Low Alloy Steel

Low alloy steel is widely used in the manufacture of automobile parts.Due to the influence of abrasive particles during movement of vehicle parts,the wear rate of parts is accelerated and parts fail prematurely,which will cause vehicle operation failures or even personal injury.Therefore,the research on the wear mechanism of automotive parts and materials has become an important topic.In this paper,the existing models of abrasive wear mainly use hardness to characterize the wear properties of materials,fail to reflect the comprehensive effects of many mechanical properties,or the deficiencies of some parameters in the model which are difficult to obtain in experiments.The abrasive wear model including hardness,strain hardening and shear strength parameters is established by the assumption of microchips caused by localization of deformation,work-energy conversion balance and material constitutive relations.The three main works in this paper can be concluded as follows:(1)The "pin-abrasive paper" abrasive wear model is established by using the Johnson-Cook constitutive model to characterize the flow stress and flow strain of the material and the balance between the work done by the tangential force of the abrasive grain and the energy required for a certain volume of material to reach the critical strain to form chips.The improved abrasive wear model is obtained by using the improved J-C constitutive model to optimize the abrasive wear model.(2)The medium carbon low alloy steel is systematically tested for its mechanical properties parameters.The material is treated with four different heat treatment processes to obtain samples with different mechanical properties.The mechanical properties of four different treated materials are obtained through hardness test,quasi-static tensile test and split Hopkinson pressure bar(SHPB)test.The J-C constitutive model is improved by introducing the thermal softening term of adiabatic temperature rise,and the improved constitutive model can be well fitted with the experimental curve.(3)A two-body abrasive wear testing machine is used to test the wear of the sample,and the wear surface morphology of the sample is observed using a scanning electron microscope(SEM).The wear surface morphology of the specimen is dominated by grooves and ridges of different widths and depths,and a certain number of plows of different sizes.This shows that the wear mechanism of the specimen is dominated by micro-cutting and multiple plastic deformations.The result of two-body abrasive wear test shows that the model has a good agreement with the sample with good ductility,and there are some deviations for poor ductility specimen,but it is still a reliable prediction model for abrasive wear.