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本文根据生产实践中出现的磨削缺陷和使用中的影响,对钢件磨削损伤产生的原因,检查和判断,以及防止方法进行了初步的探讨。材料内部的组织不均匀,热处理工艺不合理,都会影响裂纹的形成。通过对GCr15钢不同规范的热处理,结果表明,马氏体针叶随淬火温度的提高而长大,则产生磨削裂纹的倾向增加;回火不足,促进磨削裂纹的形成;残余奥氏体增加,产生磨削裂纹的机率升高。磨削应力的形成,主要来源于切削过程中的金属形变应力、热应力和组织转变应力。磨削热引起的组织应力对裂纹的形成起着重要的作用。磨削后零件表面应力状态,决定于磨削工艺。应用X射线衍射原理测量表面应力,不能真实反应表面极薄层的磨削应力状态。采用盐酸水溶液热浸可定性地确定残余应力存在的大小。而作为检查磨削裂纹,只能用硝酸溶液浸蚀检查。磨削烧伤的本质是磨削热引起的组织变化。借助于各种组织对抗酸蚀能力的不同,反应出颜色的深浅来识别烧伤的程度和性能的变化。烧伤特征随工艺条件而改变。避免磨削烧伤和裂纹的产生,对选择合理的砂轮,改变磨削工艺参数起着主导作用。材料组织的均匀性和合理的热处理工艺,对避免磨削裂纹的产生有着极其重要的意义。
In this paper, according to the occurrence of grinding defects in production practice and the use of the impact, the steel grinding damage causes, inspection and judgment, as well as prevention methods were discussed. Material within the organization is not uniform, heat treatment process is unreasonable, will affect the formation of cracks. Through the heat treatment of different specifications of GCr15 steel, the results show that the martensite needles grow with the increase of quenching temperature, the tendency to produce grinding cracks increases; insufficient tempering promotes the formation of grinding cracks; the retained austenite Increase, the probability of grinding cracks increase. The formation of grinding stress, mainly from the cutting process of metal deformation stress, thermal stress and stress transformation. Tissue stress caused by grinding heat plays an important role in the formation of cracks. After grinding parts surface stress state, determined by the grinding process. The application of X-ray diffraction principle to measure the surface stress, can not truly reflect the surface of the thin layer of grinding stress state. Hot-dip hydrochloric acid aqueous solution qualitatively determine the size of the residual stress. As a check for grinding cracks, corrosion testing can only use nitric acid solution. The essence of grinding burns is tissue changes caused by grinding heat. With the help of various organizations, the ability to resist acid erosion reflects the depth of color to identify the degree of burns and changes in performance. Burns characteristics vary with process conditions. Avoid grinding burns and cracks, on the choice of a reasonable wheel, grinding process parameters play a leading role. The uniformity of material structure and reasonable heat treatment process are extremely important to prevent the occurrence of grinding cracks.