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为总结D406A钢的静态断裂韧性KIc值与动态力学性能间的关系,分别采用三点弯曲试样以及标准冲击试样对D406A钢进行了KIc测试和仪器化冲击试验,发现室温下该材料的冲击功CVN与断裂韧度KIc存在着相同的变化趋势,两者间的对应关系与修正后的Rolfe-Novak经验公式基本相符,今后可以通过该公式来推断材料的KIc值。利用标准冲击样所获得的动态断裂韧度KId与静态断裂韧度KIc虽遵循相同的变化规律,但相关性不是特别理想,这主要是由于一方面动态加载条件下试样的受力情况远比静态下要复杂,这更容易导致KId的离散;另一方面标准冲击样并不是一个理想的裂纹体,缺口尖端在断裂之前会普遍屈服,这也会给KId的计算带来较大误差。
In order to summarize the relationship between static fracture toughness (KIc) and dynamic mechanical properties of D406A steel, KIc test and instrumented impact test of D406A steel were carried out using three-point bending specimens and standard impact specimens respectively. It was found that the impact of the material at room temperature The work CVN has the same tendency of change with the fracture toughness KIc. The correspondence between them is basically consistent with the modified Rolfe-Novak empirical formula, which can be used to deduce the KIc value of the material in the future. The dynamic fracture toughness (KId) and static fracture toughness (KIc) obtained by the standard impact samples follow the same variation rule, but the correlation is not particularly satisfactory, mainly due to the stress condition of the specimen under dynamic loading on the one hand On the other hand, the standard impact specimen is not an ideal crack body, and the notch tip will generally yield before the fracture, which will also bring a big error to the KId calculation.