通过化学分析、力学性能检测、光学显微镜、扫描电镜等实验方式,对SAE1527 汽车车轴管疲劳试验断裂试样进行失效分析.结果显示,SAE1527 车轴管疲劳寿命偏低的主要原因是热处理工艺不合理,形成了网状铁素体及贝氏体组织,进而造成了屈服强度偏低.提出在生产过程中,要保证产品的淬火温度及冷却速度改进措施,避免形成贝氏体和铁素体不良组织,提高了材料疲劳寿命.
The failure analysis on fracture samples for fatigue testing taken from the SAE1527 automotive axle tubes was carried out by test methods such as chemical analysis,mechanical performance testing,optical microscopy and scanning electron microscopy.The test results showed that the main cause leading to low fatigue lifetime service of the SAE1527 axle tubes was the unreasonable heat treatment process,which promoted to form the reticular ferrite and bainite structures,resulting in relatively low yield strengths.These improvement measures for ensuring the quenching temperatures and cooling rates in terms of the steel products in production process was proposed.So the formation of poor bainite and ferrite structures in these products was avoided and the fatigue lifetime service of such materials was improved.