| As wear resistant material, the wear-resistance of high manganese steel was superior to the other materials in the aspect of abrasion or drilling wear under strong impact and great stress. But because the initial hardness of high manganese steel was low and the deformation was relatively big in early stage of shot peening, which made initial abrasion more serious and impact on the service life of high manganese steel. To the current problem, this paper firstly studied the effect of aging treatment parameters on structure and hardness of high manganese steel by means of hardness testing, wear-resistance testing, metallographic analysis and XRD analysis, secondly studied the aging treatment parameter influence on initial deformation, wear-resisting property, hardness and structure of high manganese steel when it was shot peening, finally analyzed its work-hardening mechanics The result showed that:After the high manganese steel was treated by aging treatment, the carbide dispersed in certain directions in austenite, which made the hardness of matrix improved. The speed of the carbide formation depended on aging temperature and aging time. With the raising of aging temperature, the precipitation amount of carbide increased gradually, the hardness increased up to 236 HB at 600°C, but when the temperature was higher than 600°C, the hardness reduced because of the reduction of precipitated carbide and the formation of the ferrite phase. For different aging time at 600°C , with the prolongation of aging time, the precipitated carbide was growing constantly, at the same time the hardness firstly increased and then reduced, the hardness reached maximum of 314 HB at 600°C for 4 hours.The high manganese steel sample surface was shocked by steel ball at a high speed for 5 seconds. For the sample not treated by aging treatment, it had quantity of surface impact pits and the dimension of pit and surface coverage proportion were bigger. For the high manganese steel sample after aging treatment, at different aging temperatures, the dimension of pit and surface coverage proportion first decreased and then increased with increment of the aging temperature. For different aging time at 600°C, the dimension of pit and surface coverage proportion first decreased and then increased with prolongation of the aging time, the stable value reached maximum when the aging time was 4 hours. The dimension of pit and surface coverage proportion reached minimum at 600°C for 4 hours. This regularity was opposite to the regularity of aging processing parameters' impact on the hardness.When high manganese steel sample after aging treatment was shocked by steel ball at a high speed., the hardness of high manganese steel sample increased sharply, but with time prolonging, the hardness of sample drove to stabilization gradually. At different aging temperatures, with the aging temperature increasing, the stable value of hardness first increased and then decreased, the stable value reached maximum at 600°C. For different aging time at 600°C, with the aging time prolonging, the stable value of hardness also first increased and then decreased, the stable value reached maximum when the aging time was 4 hours.In the initial stage of shot-peening, the wearing capacity of high manganese steel was relatively big. With the prolonging of shot-peening time, the wear capacity of each sample reduced and became more and more stabilized. At different aging temperatures, the loss weight reached maximum at 600°C. For different aging time at 600°C, the loss weight reached maximum when the aging time was 4 hours.For different original samples and the sample after aging treatment, when the carbide had not been precipitated, austenite stability was better, so the mechanism of work-hardening was deformation twinning and dislocation density. When the carbide was precipitated, austenite stability reduced, its strengthening mechanism not only had deformation twinning and dislocation density but alsoα-martensite strengthening.
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