【作者】 汪旭超；

【导师】 从善海；

【作者基本信息】 武汉科技大学 ， 材料物理化学， 2011， 硕士

【摘要】 截齿由于其恶劣的工作环境,每开采1万吨煤消耗截齿400¹300个,中国目前年产煤约12亿吨,因此作为采煤机上的易损件,其需求量是非常大的。截齿系统中的齿体部分磨损失效占到其总体失效的45⁵0%。由于它的大消耗量,所以若能提高截齿的耐磨性能,会产生巨大的经济效益。本文针对于采煤机截齿磨损失效的问题,采用多种化学热处理对齿体材料40CrNiMo进行强化处理,利用XRD、扫描电镜进行渗层分析,并与未强化试样进行耐磨性对比试验,最终确定出最佳处理工艺,并探讨了齿体磨损机理。（1）气体渗碳后得到的渗层厚度约为1.3mm,碳化物弥散分布,对基体起到弥散强化作用。（2）在渗硼剂配方为52%旧渗硼剂+35%FeB+ 5%KBF+ 8%稀土氧化物（CeO）下,渗硼工艺为930℃×8h,渗硼层的相主要为Fe2B,最终的渗硼层的厚度约为123μm,平均显微硬度约为HV1518.6。（3）在渗铌剂配方为50%铌铁+32%AL₂O₃+ 10%NH₄Cl+ 8%稀土氧化镧（La₂O₃）下,渗铌工艺为990℃×7h,渗铌层的相主要为NbC,最终的渗铌层的厚度约为10μm,平均显微硬度约为HV2770。（4）在模拟截齿磨损环境下,耐磨性能从大到小依次为碳-铌复合渗,碳-硼复合渗,渗碳,未化学热处理强化试样。截齿试样的主要失效形式是磨粒磨损,磨损方式一般为切削和犁沟。更多还原

【Abstract】 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.更多还原