共查询到20条相似文献,搜索用时 109 毫秒
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磨削淬硬是利用磨削加工过程中产生的热、机械复合作用直接对钢质零件进行表面硬化的加工新技术。由于零件淬硬层深度对零件性能具有显著影响,因此对零件淬硬层深度进行预测具有工程实际意义。根据热源强度变化特点,将零件沿长度方向划分为切入区、中间区以及切出区并对热源强度模型进行优化。基于有限元方法,对磨削过程中的各区域温度场分布及瞬时温度变化进行仿真分析,并对零件的切入区、中间区及切出区的淬硬层深度进行预测。结果表明,由于加工过程中热源强度的变化,磨削加工后的零件两端均有未淬硬部分,中间区淬硬层深度最大且均匀。最后将零件淬硬层深度预测与实验结果进行对比,验证了热源优化模型的合理性和预测方法的有效性。 相似文献
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从抗疲劳制造与绿色制造的观念出发,融合预应力磨削与磨削淬硬技术原理,提出了将残余应力控制、表面淬火及磨削三者集成于一体的预应力淬硬磨削技术理论与方法。对45钢试件进行了预应力淬硬磨削加工试验,以工件淬硬层表面残余应力、硬度及粗糙度为研究对象,与相同条件下的磨削淬硬工艺试验结果进行了对比分析。结果表明:预应力淬硬磨削工艺可增大工件表面残余压应力,减小拉应力,其工件表面残余应力状态优于磨削淬硬工艺;预应力淬硬磨削工件表面硬度可以达到基体硬度的3倍左右,而工件表面粗糙度小于磨削淬硬工艺工件表面粗糙度。因此,在相同的加工条件下,预应力淬硬磨削工艺比磨削淬硬工艺具有更好的抗疲劳性、耐腐蚀性及表面完整性。 相似文献
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采用平面磨床和刚玉砂轮对40Cr钢进行了磨削淬硬,对磨削淬硬过程中磨削力的变化特征进行了深入研究.结果表明,磨削淬硬加工未出现精密磨削加工中的稳定磨削阶段,磨削淬硬过程实质是可淬硬钢的磨削淬火烧伤过程.与普通磨削不同,磨削淬硬过程中的磨削力比随磨削深度的增加而相应增大;但磨削力比均较小,其值在1.0-2.0之间变化. 相似文献
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采用外圆磨削方式对40Cr调质钢进行磨削淬硬试验,通过测量试样的金相组织和显微硬度对外圆磨削淬硬的可行性、磨削参数对淬硬效果的影响规律等进行研究。结果表明:40Cr钢外圆磨削淬硬是可行的;试样的表层组织由完全淬硬层、过渡层和基体组成;表面硬度均在690 HV左右,淬硬层深度最高可达1.10 mm;磨削深度对表面硬度无显著影响,但对淬硬层深度具有显著影响,工件速度和砂轮型号对表面硬度及淬硬层深度均无显著影响。 相似文献
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非调质钢磨削强化效果的研究 总被引:1,自引:0,他引:1
磨削强化是利用磨削热对工件表面进行淬硬处理的新工艺,在技术上能代替感应淬火等表面热处理工艺,可以减少加工工序,降低生产成本。本研究为曲轴等非调质钢零件的实用性研究提供参考。 相似文献
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介绍PowerMILL与PowerSHAPE在数控加工仿真中应用的一个具体案例。详细介绍了在PowerMILL与PowerSHAPE中数控铣削冷锻模具的工件坐标系设置、刀具选择、辅助曲面创建、加工策略与参数、路径模拟、后置处理等内容,有相当的参考价值。 相似文献
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Wang KezhengChen XinzhengJia GaofengDepartment of Mechanical Engineering Tsinghua University Beijing China 《机械工程学报(英文版)》2004,17(1):78-81
An automatic seam tracking system used in submerged arc welding is presented. In the system, the linear CCD vision sensor is installed in front of the welding torch. Laser structure light emitted by the semiconductor laser irradiates on a slant to work-piece surface and forms a structure light strip on work-piece surface. Scatter light of the strip is received by linear CCD on top of the seam and the image information of seam can be obtained. By way of image processing and applying Fuzzy-P controller in tracking process, automatic seam tracking has been realized accurately. Anti-disturbing ability of the system to work-piece surface status has been enhanced largely by classified microadjus-tment of torch height. 相似文献
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介绍了一种基于旋转磁性抛光液体的抛光技术。磁性抛光液体在磁力搅拌器的作用下产生旋转运动,利用外加强磁场作用增大磁性液体的粘度和剪切屈服应力,当加工工件放入磁性抛光液体中,磁性抛光液体与之相接触的工件表面发生磨削,从而达到对工件表面的光整加工。实验详细研究了磁性抛光液体抛光后工件的抛光区内表面粗糙度与抛光时间和位置之间的关系,实验结果表明:旋转磁性抛光液体抛光可以用于对工件进行超光滑加工,抛光时间越长,各处粗糙程度越接近,表面粗糙度越好,并且表面粗糙度比单独用研磨抛光膏的效果好。 相似文献
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Lin Yang Shi Wu Xianli Liu Zhijing Liu Meiwen Zhu Zhonghua Li 《The International Journal of Advanced Manufacturing Technology》2018,98(1-4):151-163
In the milling process of automobile panel mold of hardened steel, the characteristic of free-form surface is one of the dominant factors for surface topography. In this paper, the trajectory of cutting edge is firstly modeled to analyze the residual height of the free-form surface in ball-end milling of hardened steel. Furthermore, the non-uniform rational B-splines (NURBS) surface reconstruction is utilized to generate the surface topography. Subsequently, the influences of surface curvature, lead angle, milling vibrations on the machined surface topography, and residual height are investigated, respectively. Finally, the accuracy of the surface topography and the roughness prediction model are validated by the milling experiments of free-form surface, where two-dimensional contour maps could be obtained. The simulation and experimental results demonstrate that the machined surface topography of hardened steel is fitted by means of NURBS surface reconstruction. In that manner, the effects of surface characteristics on the machined surface topography can be accurately predicted. 相似文献
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Peipei Sun Shaoxia Li Gang Yu Xiuli He Caiyun Zheng Weijian Ning 《The International Journal of Advanced Manufacturing Technology》2014,70(5-8):787-796
For laser surface hardening (LSH) of large-sized workpieces, a wide and uniform hardened layer of a single track is pursued. In this study, two kinds of shaped laser beams were used in LSH of 42CrMo cast steel to obtain the required hardened layer. One is a stripy spot with uniform-intensity array spots and the other a stripy spot with intensity blowup in the edge of the whole array spots. As a comparison, a Gaussian laser beam was also adopted. A three-dimensional finite element model was used to simulate the thermal history of specific points by the latter shaped beam and the Gaussian laser beam. The surface morphology, microstructure, microhardness, and uniformity of hardened layers were studied. The results showed that a wider and more uniform hardened layer could be obtained using the latter shaped beam at relative higher scanning velocities and laser power. The thermal history of a material has an important effect on the microstructure and microhardness finally formed. Due to the high peak temperature and heating rate caused by the latter shaped beam, a higher value of microhardness in the transformation hardened zone was found. 相似文献
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轴承套圈锻造过程的计算机仿真研究 总被引:1,自引:0,他引:1
本文运用MSC-Marc软件对轴承锻造加工过程进行了计算机仿真.以金属成形理论和有限元方法基本原理为基础,建立了热力偶合刚粘塑性轴承锻造模型.包括对材料特性进行了完整的描述,确定了成形模拟中体积不可压缩实现方法.以二代轮毂轴承外圈锻造为例进行模拟分析.模拟分析中进行了冲头力的计算及对两次预成形模型的实验和模拟结果的对比;提出了产生过大冲头力的一个原因是最终成形阶段工件在模腔内分布不均使变形速率急剧增加;分析了工件应力和模具结构的关系及其优化问题,对冲头的倒角圆弧半径作了优化;对温度效应、表面质量和金属流线等锻造设计有关问题作了讨论.提出了预成形坯的设计优化准则,以此设计了二代轮毂轴承外圈的优化的预成形结构,冲头力比原设计下降了一半以上. 相似文献
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概述了塑性成形的基本原理,分析了螺杆钻具接头在热镦挤成形过程中载荷随工件变形量的变化、工件表面应力以及工件在成形过程中的金属流动情况,确定了螺杆钻具接头热镦挤成形所需要的镦挤压力和成形温度,设计了热镦挤成形试验装置的基本结构,并通过试验验证了这种螺杆钻具接头加工方法的可行性。 相似文献