二次带状组织对低合金非调质钢疲劳性能的影响

Effect of secondary banded structure on the fatigue properties of non-quenched and tempered micro-alloyed steel

摘要: 采用应力比为0.1的轴向拉伸疲劳试验分别研究了低合金钢DG20Mn和35CrMo钢的疲劳性能与带状组织的关系.结果表明:带状组织对试验材料的轴向拉伸性能没有明显影响,对35CrMo钢的轴向拉伸疲劳性能影响较小,但严重减弱DG20Mn钢的轴向疲劳性能.带状组织对疲劳性能的影响主要是由于在高的疲劳拉应力下,带状组织引发疲劳微裂纹、微空洞等疲劳损伤,导致疲劳裂纹萌生及扩展模式发生变化,从而影响疲劳性能.

Abstract: The effect of banded structure on the fatigue properties of DG20 Mn and 35 Cr Mo micro-alloyed steels was investigated by using axial tensile fatigue tests at a stress ratio of 0.1. The results show that secondary banded structure has no significant effect on the axial tensile properties of the tested steels and the axial tensile fatigue performance of 35 CrMo steel,but decreases the axial tensile fatigue performance of DG20 Mn steel. Under the high cyclic tensile stress,multi-source damage cracks in the steels initiated by secondary banded structure,which changes the fracture mode,is the major factor of the decrease in fatigue life of the steels.