C-Mn钢及焊缝金属各韧性的统一性

在系列温度下测定了16MnR钢及三种焊缝金属的四项韧性指标:VCharpy冲击韧性、预裂纹Charpy冲击韧性、四点静弯缺口韧性和断裂韧度COD,同时测定了四种材料的屈服强度。发现四项韧性指标的延脆转变温度可以通过各材料的屈服强度对温度和加载速率的依赖而统一起来,各韧性的延脆转变现象均由局部解理条件所控制,为简化工程材料抗断性能的评定和断裂理论研究的深入提供了可能。

Unificaion for Various Toughnesses of C-Mn Steel and Welds

In this work, the measurement of four types of toughnesses, i. e. the V-notched Charpy absorbed energy, the pre-maximum load energy of pre-cracked Charpy speci- mens, the fracture load ratio by four point bending, and the crack tip openning displacement, as well as the measurement of yield strengths are carried out on a C-Mn steel and three kinds of weld metals under various test temperatures. The unification for the four toughnesses defined as ductile-to-brittle transition temperature region could be realized through the dependence of material's yield strengths on test temperature and loading rate. The ductile to brittle transitions of the four toughnesses are all determined by the local cleavage conditions. This results make it possible to simplify the evaluation procedure of frcature properties of engineering metallic materials and to investigate further into the fracture theory.