| The consumption of cutting pick is from 400 to 1300 to explore 10000 tons coal because of poor working conditions. At present, the annual output of coal is 1.2 billion tons in China, with the result of which the quantity of cutting pick is very large. The failures of cutting pick body parts in cutting systems account from 45% to 50% over all the failure of wear failure. Because of the quantity of consumption, it will permit enormous economic benefits if the wear resistance of cutting teeth can be improved.This article studies the wear failure of shearers cutting pick, variety of chemical heat treatment is applied to improve strength, XRD and SEM are used to analysis of diffusion layer and comparison with non-strength sample, find the best heat treatment and discuss the wear mechanism(1) Gas carburizing workers get the carburized layer thickness is about 1.3mm; carbides dispersed on the substrate play the role of dispersion strengthening.(2) In the formula for making boronizing agent: the old formula of 52% boronizing agent +35% FeB + 5% KBF + 8% CeO, the infiltration of boron thermal process is at 930℃for 8 hours, the main phase boride layer is the Fe2B, the final thickness of boride layer is about 123μm, the average hardness of about HV 1518.6.(3) In the seepage niobium formula is 50% niobium iron +32% AL2O3+ 10% NH4Cl + 8%La2O3, the seepage niobium process is at 990℃for 7 hours, seepage niobium layer phase mainly is NbC, niobium layer permeability was the final thickness of about 10μm, the average hardness of approximately HV2770.(4) In a simulated environment of abrasion, the wear resistance in order from largest to smallest is C-Nb composite diffusion; C-B composite diffusion, carburizing, heat treatment is not enhanced chemical samples. Pick the main failure mode of the sample is abrasive wear, the wear mode generally cutting and plowing. |
