韧脆转变低温区断裂韧度分析

ANALYSIS ON FRACTURE TOUGHNESS AT LOWER TEMPERATURE REGION OF THE DUCTILE-BRITTLE TRANSITION

为了分析韧脆转变低温区的延伸区宽度变化及韧性陡升的原因,对C-Mn钢预裂纹试样在不同温度下进行三点弯曲裂纹尖端张开位移试验,并用SEM(scanning electron microscopy)对所有的断口进行仔细观察。结果发现在韧脆转变温度区SZW(stretch zone width)存在一临界值;韧脆转变低温区韧性陡升与SZW有关;韧脆转变低温度区COD(crack-tipopening displacement)值与SZW呈线性关系。

In order to study the variable of stretch zone width(SZW) and a sharp upturn of the fracture toughness in lower temperature region of the ductile-brittle transition.The experiments of three point bending(3PB) crack-tip opening displacement(COD) for pre-cracked specimens of C-Mn steel was performed at different temperatures,then all fracture surfaces were observed carefully by SEM(scanning electron microscopy).The results show that the critical value of SZW is existed in the ductile-brittle transition region...