基于声发射技术的30CrMnSi钢断裂机理研究  

Fracture Mechanism for 30CrMnSi Steel Based on Acoustic Emission Technology

作　　者：龙宪海[1] 阳能军[1] 王汉功[1] 

机构地区：[1]第二炮兵工程学院,西安710025

出　　处：《材料工程》2011年第1期17-22,共6页Journal of Materials Engineering

摘　　要：采用三点弯曲试样加载过程声发射监测实验,结合断口SEM观察及X射线能谱分析,考察了30CrMnSi合金钢延性断裂的整个物理过程。结果表明:30CrMnSi钢的断裂过程从宏观上可以分为裂尖塑性变形、裂纹亚临界扩展和裂纹失稳扩展三个阶段。其机理如下:裂尖塑性变形过程是位错的滑移、堆积而引起的孔洞形核和长大;裂纹亚临界扩展过程为韧窝之间的连通;裂纹失稳扩展过程则是晶体的大规模解理。随着延性断裂过程的进行,各阶段均呈现脆性断裂特征逐渐增强的趋势,表现为韧窝尺寸的减小和声发射高幅值信号的增加。断裂过程各阶段声发射信号特征明显,声发射技术是监测30CrMnSi钢断裂损伤发展的有效手段。The whole physics process of ductile fracture in 30CrMnSi steel was investigated by the experiment of three-point bending specimen,which was monitored by acoustic emission system and the analysis of fracture by SEM and X-ray spectrometer.The results indicate that the whole process of the fracture includes there stages： the plastic deformation of crack tip,the crack pre-critical propagation and the crack critical propagation.The process of plastic deformation of crack tip is the formation and growth of cavity.The essential of crack pre-critical propagation is the connection of the dimples and the crack critical propagation is attributed to large-scale cleavage.There is a tendency to be more brittle during ductile fracture propagation for all stages.It is testified that acoustic emission technology is an efficient means to monitor the damage propagation for the high strength steel.

关 键 词：高强度合金钢 声发射 断裂机理 断裂韧度 

分 类 号：TG113.25[金属学及工艺—物理冶金]