论文部分内容阅读
在NENE-2型微动疲劳试验机上对弯-弯条件下PD3、U71Mn钢的疲劳裂纹扩展特性进行了研究。结果表明:相同弯-弯条件下,U71Mn钢中的疲劳裂纹较PD3钢中的短,因而具有较好的抗疲劳性能;其原因在于U71Mn钢的塑性较PD3钢的好,使得裂纹尖端钝化,同时其细小的珠光体具有更多的晶界,从而为能量的耗散提供了更多的途径,最终使得裂纹在U71Mn钢中较在PD3钢中不容易扩展。
The fatigue crack growth characteristics of PD3 and U71Mn steel under bending-bending conditions were studied on a NENE-2 fretting fatigue tester. The results show that under the same bending-bending conditions, the fatigue crack in U71Mn steel is shorter than that in PD3 steel, so it has better fatigue resistance. The reason for this is that the plasticity of U71Mn steel is better than that of PD3 steel and the crack tip is passivated , While its fine pearlite has more grain boundaries, which provides more ways for energy dissipation and finally makes the crack not easy to expand in U71Mn steel compared with PD3 steel.