组织和成分因素对低碳结构钢解理断裂应力及断裂韧性的影响

Effects of Microstructure and Composition on Cleavage Fracture Stress and Fracture Toughness of Low Carbon-structural Steel

本文揭示了板条组织的解理断裂应力在整个试验温度范围内是不依赖于温度而变化的。表明组织类型对解理断裂有重要影响:马氏体组织具有极高的解理断裂应力以及在同样试验温度下低的断裂韧性,铁素体截然相反,贝氏体位于其间。此外碳含量有其附加影响。切口试样测得的解理断裂应力明显高于光滑试样。

It has been revaled that the cleavage fracture stress of lath microstruc-ture is independent of temperature in the whole range of testing temperature. There are significant effects of different microstructures on cleavage fracture. Martensite has extremely high cleavage fracture stress ( OC ) , and low fracture toughness ( Kc ) at the same testing temperature. On the contrary, for ferrite material: low Oc and high Kc, and upper bainite is between them. Besides, carbon has an additional effect. The cleavage fac-ture stress of notched specimen is much higher than that of smooth specimen.