共查询到17条相似文献,搜索用时 78 毫秒
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以切入式平面磨削淬硬加工试验为基础,对40Cr钢磨削淬硬层的宏观组织、显微硬度和淬硬层深度进行了研究.结果表明,磨削淬硬层由完全淬硬区和过渡区组成,磨削条件对磨削淬硬层高硬度区的组织及其显微硬度无显著影响,显微硬度值均在630~680HV0.5之间.选用细颗粒、高硬度的陶瓷结合剂刚玉砂轮和低进给速度、大切深参数并结合顺磨方式可增大磨削淬硬层深度. 相似文献
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采用刚玉砂轮在普通平面磨床上对65Mn钢进行磨削淬硬,研究磨削深度和工件进给速度对65Mn钢磨削淬硬层深度及其均匀性的影响。结果表明:试件淬硬层由完全淬硬层、过渡层组成;淬硬层最大深度随磨削深度的增大而增大,随工件进给速度的增加而减小;在本试验条件下,磨削深度ap0.4mm时,试件表层全部淬硬,均匀性较好。 相似文献
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以磨削淬硬实验为基础,研究了单程磨削淬硬过程中磨削深度、工件进给速度对淬硬层深度的影响;同时通过建立最大磨削淬硬层深度的计算模型并结合Matlab软件的数值仿真功能,对45钢最大磨削淬硬层深度进行模拟仿真。结果表明:最大磨削淬硬层深度随着磨削深度的增加或者工件进给速度的减小而增加;采用Matlab对最大磨削淬硬层深度进行数值仿真得到的结果与实验结果吻合度较高,通过建立适当的数学模型可以有效地预测最大磨削淬硬层深度。 相似文献
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低温纳米粒子微量润滑(Nano-CMQL)是将低温冷风技术与纳米粒子润滑油两者有效结合起来的一种高效绿色新型磨削加工润滑方法。采用60目陶瓷结合剂的氧化铝砂轮对GCr15淬硬轴承钢进行磨削试验,比较了常温干式、浇注式、低温冷风微量润滑(CMQL)以及Nano-CMQL四种工况在不同磨削参数下的法向磨削力、比磨削能、磨削温度、工件表面轮廓及粗糙度,结果表明,在基础磨削液中加入粒径为40 nm的MoS2固体颗粒制备出的Nano-CMQL磨削液能够有效地减小磨削加工过程中的法向磨削力并降低磨削温度,尤其在高速、大磨深的磨削参数下,其磨削加工性能更加优良。 相似文献
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吴良芹 《机械制造与自动化》2015,44(2):76-77,85
采用刚玉砂轮在普通平面磨床上对60Si2Mn钢进行了磨削硬化,研究其硬化层组织及变化规律。结果表明:表面磨削强化工艺可获得760HV以上的高硬度淬硬层,最大淬硬层深达2.0 mm;磨削淬火加热速度极快,细化了奥氏体晶粒,淬火马氏体组织非常细小,得到板条马氏体和片状马氏体的混合组织。 相似文献
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通过淬硬轴承钢GCrl5的磨削实验,研究了砂轮速度、工件速度、磨削深度以及冷却方式等磨削参数对白层厚度的影响规律.实验表明:白层是由磨削过程中工件快速升温和快速冷却以及强烈的塑性变形引起的,白层厚度的变化是磨削加工过程中各种参数共同作用的结果,而其中磨削深度是主要原因,其次是砂轮速度和工件速度;白层厚度随砂轮速度和磨削深度的增大而增大;低的砂轮速度和磨削深度以及良好的冷却条件能有效抑制白层的产生.根据实验统计结果提出了预测磨削白层厚度的经验公式. 相似文献
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Numerical Calculation and Experimental Research on Residual Stresses in Precipitation-hardening Layer of NAK80 Steel for Shot Peening 总被引:1,自引:1,他引:0
MIAO Hong ZUO Dunwen WANG Min ZHANG Ruihong WANG Hongfeng Jiangsu Key Laboratory of Precision Micro-Manufacturing Technology Nanjing University of Aeronautics Astronautics Nanjing China College of Mechanical Engineering Yangzhou University Yangzhou China 《机械工程学报(英文版)》2011,(3):439-445
Shot peening can improve fatigue strength of materials by creating compressive residual stress field in their surface layers,and offers a protection against crack initiation and propagation,corrosion,etc.And fatigue fracture and stress corrosion cracking of NAK80 steel parts are improved effectively.Currently there lacks in-depth research in which the beneficial effect of the residual stress may be offset by the surface damage associated with shot peening,especially in terms of the research on the effective control of shot peening intensity.In order to obtain the surface residual stress field of NAK80 steel after shot peening,the samples are shot peened by pneumatic shot peening machine with different rules.The residual stress in the precipitation-hardening layer of NAK80 steel is measured before and after a shot peening treatment by X-ray diffraction method.In order to obtain true residual stress field,integral compensation method is used to correct results.By setting up analytical model of the residual stress in the process of shot peening,the surface residual stress is calculated after shot peening,and mentioning the reason of errors occurred between calculated and experimental residual stresses,which is mainly caused by the measurement error of the shoot arc height.At the same time,micro hardness,microstructure and roughness in the precipitation-hardening layer of NAK80 steel before and after shot peening were measured and surveyed in order to obtain the relation between shot peening strength and surface quality in the precipitation-hardening layer.The results show that the surface quality of NAK80 steel is significantly improved by shot peening process.The over peening effect is produced when the shot peening intensity is too high,it is disadvantageous to improve sample’s surface integrity,and leading to reduce the fatigue life.When arc high value of optimal shot peening is 0.40 mm,the surface quality is the best,and the depth of residual stress in the precipitation-hardening layer reaches to about 450 μm.Numerical calculation is very useful to define the process parameters when a specific residual stress profile is intended,either to quantify the benefits on a specific property like fatigue life or to help on modeling a forming process like shot peen forming.In particular,the proposed parameter optimization in the progress of shot peening and effective control of the surface texture provide new rules for the quantitative evaluations of shot peening surface modification of NAK80 steel. 相似文献