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本文叙述了对球墨铸铁曲轴轴颈与园角部位同时高频淬火后获得的硬化层分布,以及硬化层中残余应力分析。采用此工艺园角部位产生了压应力,从而可以提高曲轴运转时的疲劳强度,防止断裂事故。高频淬火后回火时,随着回火温度的升高,残余应力重新分布。260℃回火后沿轴颈及园角部位残余应力分布均匀,园角部位压应力也增大。由回火温度与硬度变化曲线证实,残余应力重新分布是与残余奥氏体转变相关联。高频淬火再不同温度回火后的抗摩擦磨损性能试验结果,也是240—280℃回火最好,这就为回火温度的选择提供了依据。因此认为高频淬火再200℃回火的常规工艺对轴颈与园角同时高频淬火曲轴而言,并不适用。
This paper describes the hardened layer distribution obtained after simultaneous quenching of the journal and corner of the nodular cast iron crankshaft and the analysis of the residual stress in the hardened layer. The compressive stress is generated in the corner of the corner of the process, so that the fatigue strength during cranking operation can be improved and the fracture accident can be prevented. After high-frequency quenching, tempering, with the tempering temperature increases, the residual stress redistribution. After tempering at 260 ℃ along the journal and corner parts of the residual stress distribution, corner compression stress also increased. Confirmed by the curve of tempering temperature and hardness, the residual stress redistribution is related to the residual austenite transformation. After high-frequency quenching and tempering at different temperatures after the anti-friction and wear test results, but also the best tempering 240-280 ℃, which provides the basis for the choice of tempering temperature. So that the conventional high-frequency quenching and then tempering at 200 ℃ on the journal and corner at the same time high-frequency quenching crankshaft, does not apply.