中碳钢疲劳寿命的估算方法研究

Investigations of Medium Carbon Steel Fatigue Life Predictions

中碳钢有着较好的机械和力学性能,其疲劳特性是机械和力学性能的主要考核指标之一,也是研究的重点和难点。中碳钢疲劳寿命的传统估算方法在高周上存在计算精度低的问题,主要原因可归结为疲劳强度指数难以在全周,即:低周、中周和高周,实现统一表达。因此,针对中碳钢疲劳强度指数开展研究,提出了疲劳强度指数全周分段计算方法;开展了基于传统疲劳寿命估算方法和所提出估算方法的中碳钢40Cr疲劳寿命预测分析;并利用来自于参考文献的中碳钢40Cr疲劳寿命试验数据,开展了预测结果的对比分析;分析结果表明基于提出的疲劳强度指数全周分段计算方法所形成的中碳钢疲劳寿命估算方法较传统疲劳寿命估算方法提升了高周寿命预测精度;这将为提高金属材料疲劳寿命预测分析提供一定支持和帮助。

Medium-carbon steels occupy superior mechanical property. Fatigue characteristic is one of the key evaluation indexes of mechanical properties,and is also the focus and difficulty of the mechanical property study. The traditional estimation method of fatigue life of medium-carbon steel is low accuracy in high cycles. The main reason is that fatigue strength factor is difficult to realize the unified calculation in the whole cycle. Therefore,in this issue,medium-carbon steel fatigue strength index is investigated,and a sectional calculation method of calculate fatigue strength factor in whole cycle is proposed. The fatigue life of 40Cr is estimated by the traditional method and the proposed method. Comparisons are made with the 40Cr fatigue life test data from the reference. The results indicate that the proposed method could improve the prediction accuracy in the high cycle life compared with the traditional fatigue life estimation method. The fatigue life estimation method proposed in the issuer would improve the fatigue life prediction accuracy of metal materials.