金属材料J—R曲线及条件起裂值的单试样三曲线法

MEASUREMENT OF J R CURVE AND THEIR PROOF VALUES AT CRACK INITIATION FOR METALS WITH METHOD OF THREE CURVES FROM SINGLE SPECIMEN

用单试样三曲线法测定了１２ＣｒｌＭｏＶ、１．２５Ｃｒ０．５ＭｏＳｉ、１６ＭｎＲ三种钢材和一种焊缝金属的Ｊ积分阻力曲线及其条件起裂值，与标准的多试样法测定结果基本吻合。实验表明，单试样三曲线的关联分析反映裂纹三点弯曲试样的宏观断裂物理过程，延性裂纹的扩展符合幂函数规律。

The measurement of J-resistance curves and their proof values at crack initiation by using12CrlMoV、1.25Cr0.5MoSi、16MnR steels and a weld metal were carried out with the method of three curves fromsingle specimen. The results of single specimen were in agreement with those of standard multi-specimenmethod. It have shown from the experiments that the connected analysis of the three curves from single specimenis in accordance with the physical fracture processes of precracked three point bending specimens.The ductile crackextension of them follows the power law relation.