对于带有I型裂纹的SM490A钢和SUS304钢试样，通过测量其在拉伸断裂过程中的声发射特征参数及裂纹尖端特定点的温度，分析了裂纹尖端和塑性变形区域的力学特征。结果表明：声发射能量计数、振铃累积计数在裂纹扩展的各个阶段都有着明显的曲线特征，且曲线特征和屈服、强化阶段的应力-应变曲线基本吻合，因此可以用声发射能量计数、振铃累积计数来描述屈服、强化阶段的塑性变形情况；塑性变形率决定了变形至断裂过程中试样的温度变化；对于带有I型裂纹的SM490A钢和SUS304钢，其声发射信号主要集中在塑性变形阶段和裂纹扩展阶段。

For SM490A steel and SUS304 steel samples with I type cracks, the mechanical characteristics of cracks tip and plastic deformation regions were analyzed by measuring the acoustic emission characteristic parameters and the temperatures at the specific points of crack tips during tensile fracture. The results show that the acoustic emission energy count and ring cumulative count have obvious curve characteristics in each stage of crack growth, and the curve characteristics are basically consistent with the stress-strain curves of yield and strengthening stages. Therefore, the acoustic emission energy count and ring cumulative count can be used to describe the plastic deformation at the yield and strengthening stages. The temperature change of sample from deformation to fracture be determined by plastic deformation rate. For SM490A steel and SUS304 steel with I type cracks, the acoustic emission signals mainly focus on the plastic deformation stage and crack growth stage.