热成形温度对49MnVS3曲轴组织性能的影响

Effect of Hot-forming Temperature on Microstructure and Properties of 49MnVS3 Crankshaft

针对49MnVS3曲轴产品服役寿命低的问题,本文对与曲轴随炉处理的标准拉伸试样进行了拉伸试验和疲劳试验。结果表明,试样的伸长率偏低(8.53%);99%存活率下的疲劳极限值仅为340.25 MPa。据此,对试样晶粒度展开评估,并对正火温度与晶粒度之间的关系进行了深入研究。结果表明,随着正火温度的增加,晶粒逐渐长大,晶粒度减小;当温度超过1180℃时,晶粒度等级低于4级,出现"过热"现象。

Aiming at the problem of low service life of 49MnVS3 crankshaft, tensile testing and fatigue testing of the crankshaft standard tensile specimen under the same treatment were carried out. The results show that the elongation of samples is low （8.53%）; the fatigue limit under 99% survival rate is 340.25 MPa. Based on the above, the grain size of the sample was evaluated, and the relationship between normalizing temperature and grain size was deeply researched. The results show that with the increase of normalizing temperature, the grains grow gradually, and the grain size decreases; when the temperature is more than 1180℃, the grain size is lower than 4 class, and the ＂overheating＂ phenomenon appears.