摘要: Induction surface hardening creates very desirable residual stresses in the hardened surface layer. Residual stresses are always of a compressive nature and are usually present to the depth of the induction-hardened layer. By the appropriate selection of grinding wheel and grinding conditions and taking into account the physical and mechanical properties of the workpiece material very favourable compressive residual stresses in the hardened surface layer can be retained.
How is it possible to assure a desirable surface and surface layer quality after induction hardening and fine grinding? Finding an answer to this question requires a very good knowledge of the process of grinding on the micro-level as well as knowledge of mechanical and heat effects acting on the layer of the workpiece including the type and condition of the grinding wheel. An allinclusive consideration of the numerous influences of the kind and condition of the tool on the changes on the surface and in the surface layer of the workpiece in the given machining conditions
is described by the term “surface integrity”.

346

作者: Volkan Güley, A. Erman Tekkaya, Turhan Savaş, Feridun Özhan

摘要: The aim of this study is to investigate surface residual stresses after heat treatment and
grinding processes in the production of rollers. The residual stresses were measured using the X-ray
diffraction method utilizing chromium radiation, which has an average penetration depth of 5 μm
incident on AISI-E52100 (100Cr6) ball bearing steel. Taguchi design of experiments (DOE) is
applied to define the set of experiments for grinding, which facilitates evaluation of the individual
influences of process parameters on residual stresses and also eliminates unnecessary experiments.
Response of residual stresses to each parameter is evaluated with the help of the results of residual
stress measurements by X-ray diffraction. In grinding with aluminum oxide wheels, it was
concluded that the lower the cutting speed and the higher the workpiece speed the higher the
magnitude of surface compressive residual stresses. Higher compressive stresses were measured in
axial direction compared to the circumferential direction after the grinding process.

317

作者: Cong Mao, Zhi Xiong Zhou, De Wang Zhou, Du Yi Gu

摘要: In order to understand the grinding mechanism and analyze the grinding operation, it is
necessary to study the contact phenomena between wheel and workpiece during grinding operation.
The contact length, the grinding temperature distribution within the contact zone, and the grinding
forces are measured in-process by using Critical Contact State mode, thermocouple method, and
3-axis piezoelectric dynamometer, respectively. It is found that the grinding conditions and the
properties of work material have effects on the contact length, moreover, the mechanism of which is
discussed in this paper. The results show that the contact length significantly interacts with grinding
force and grinding temperature in the grinding zone.

128

作者: Chong Lue Hua, Gui Cheng Wang, Hong Jie Pei, Gang Liu

摘要: Thermal stresses of grinding plays an important role on the fatigue and wear resistance of the component. A comprehensive analysis of thermal stress induced by surface grinding has been conducted with aid of the finite element method. To obtain a reliable figure of thermal stress induced by grinding, temperature-dependent properties of workpiece materials were taken into account. The developed finite element procedure has also been applied to calculate the surface and sub-surface thermal stress induced by moving source of triangular heat when convection and radiation is occurred over the whole work. Based on an analysis of the effects of wheel velocity on the thermal stress distributions in an elastic-plastic solid, some important conclusions were given.

2211

作者: Q.S. He, Y.C. Fu, Jiu Hua Xu, B.F. Zhang

摘要: A three dimension heat transfer model, using a commercial code Fluent software which was based on FEM, was developed to describe the grinding process of heat pipe grinding wheel in this paper. Temperature field of heat pipe grinding wheel was analyzed by this model to identify the effects of different conditions on the temperature of the work surface of grinding wheel including the heat flux of contact zone, cooling parameter and rotation speed of grinding wheel. The heat exchange performance of heat pipe grinding wheel also was studied based on the temperature of the work surface of grinding wheel. Model calculations showed that the high heat flux and unsatisfactory cooling capacity could cause a high temperature of the work surface of grinding wheel as well as the temperature of the work surface of grinding wheel was not affected by the rotation speed of grinding wheel. A significant amount of the input heat could be taken away from the heat pipe grinding wheel.

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