| 18CrNiMo7-6 steel has a series of advantages such as excellent process performance,high service life and low cost.Its high tensile strength,toughness and impact resistance make it adaptable in various complex environments.18CrNiMo7-6 steel is an important raw material in the production and manufacture of gear and other precision parts,and is involved in major industrial production and processing at present.However,in the advanced manufacturing industry,surface grinding is an important process for the effective machining of precision parts,and the fatigue characteristics and machining efficiency of precision parts cannot be effectively guaranteed,which ultimately affects the service life of the parts.Through the research summary,it can be found that the research on surface grinding precision has already put forward a lot of theoretical derivation,and has some practical and results,but the basic machining mechanism and grinding burn research need to be further improved.In this paper,with the purpose of prolonging the service life of parts and ensuring the production efficiency,single-factor surface grinding process test was designed by using single-layer electroplating cBN wheel.Starting from the grinding process characteristics and surface quality characteristics of 18CrNiMo7-6 steel,the surface grinding burn mechanism of this material was deeply studied.Two important characteristics of grinding force and grinding temperature were verified by theoretical derivation and experimental test.The mutual detection of surface microhardness and metallographic microstructure is helpful for us to study the surface quality after grinding,and it is of great significance for us to further understand the mechanism of high-speed grinding and its morphological characteristics and metallographic microstructure changes during grinding and burn.The effect of grinding parameters on grinding force,grinding temperature,surface morphology and surface roughness can be studied and summarized to improve the machining efficiency.The main steps taken are:(1)The properties and grinding process of 18CrNiMo7-6 steel were studied.XRD diffractometer and electron microscope were used to scan and detect the microscopic elements on the surface of the material,and the properties of the material under normal temperature were studied.A single factor grinding test was carried out at room temperature.The study of single factor grinding test is helpful to understand the range of grinding burn under specific process conditions,so as to lay the data analysis foundation for the next orthogonal experiment.The main wear patterns and the conditions of grinding burn in surface grinding under different process conditions were analyzed and the influence on the grinding performance of high strength 18CrNiMo7-6 steel was obtained.(2)Theoretical derivation of grinding temperature and force of 18CrNiMo7-6 steel.At room temperature,it is necessary to monitor the temperature and grinding force in the grinding process when grinding test samples under different technological conditions.The changes of force and temperature in grinding process with different grinding processes are studied,and the stress conditions and heat transfer of temperature are theoretically derived and analyzed.The empirical formula of grinding force changing with process parameters and its heat input formula are obtained,so as to make a predictive study on grinding force and grinding temperature.(3)Study on grinding burn mechanism of 18CrNiMo7-6 steel.The bowl type monolayer electroplated cBN grinding wheel for 18CrNiMo7-6 steel grinding,mutations on the grinding force ratio,and grinding temperature sudden rise in the surface of the samples for further testing and microstructure research,and through the micro hardness tester,metallographic microscope microstructure analysis of samples before and after the grinding and summarizes test rule,explores the different grinding process occurs under the condition of grinding burn and its microstructure microhardness change when change rule. |
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