一种中碳钢的韧脆转化以及热激活分析

THE DUCTILE TO BRITTLE FRACTURE TRANSITION OF A MEDIUM CARBON STEEL AND THE THERMAL ACTIVATION ANALYSIS

继前期工作，研究了一种中碳钢由加载速率引起的韧脆转化。在恒定的温度下，随速率增加，断裂韧性不断降低，该现象与降低温度引起的韧脆转化相同。通过热激活分析，断裂韧性可以分为两部分：非热分量Ｊａ和热分量Ｊｔ，并获得了断裂韧性与温度、加载速率的定量化关系。对形变激活能与断裂激活能的关系以及与温度的关系进行了初步的探讨。

Continuing the previous research, the paper investigated a ductile to brittle fracturetransition caused by loading rates with a medium carbon steel. As the increase of loading rateat constant temperatures, fracture toughness decreases continuously, which is similar to thatin a changing temperature test. Through thermal activation analysis, the toughness can bedivided into two parts:athermal one Ja and thermal component Jt. And the quantitative rela-tionship of fracture toughness with temperature and loading rate has been obtained.