低碳钢内裂纹热愈合时的耗散结构

为研究钢内裂纹愈合机理,对经过热愈合处理的稀土Q235钻孔压缩试样的组织进行了光学显微镜和SEM电镜观察与分析.结果表明,低碳钢在热愈合过程中产生了两类耗散结构特征:基体中片状珠光体的溶解;裂纹愈合区组织的形成.分析认为,含内裂纹的低碳钢是远离平衡态的开放系统,热愈合过程中存在着反应扩散非线性基本条件,存在浓度起伏、结构起伏、能量起伏等涨落因素,因此导致了材料内部有序耗散结构的产生.

Dissipative structures of inner cracks in low carbon steel during thermal healing

Thermal healing processing of Q235 steel with La addition was carried out in order to study the healing mechanism. An inner crack was made by compressing a drilled hole on the sample. The microstructures of samples were analyzed by means of optical microscope and SEM. The results showed that two types of dissipative structures obtained during heating healing for low carbon steel. One type was the dissolution of lamellar pearlite in host and the other was the formation of structure at crack healing zone. It was proposed that low carbon steel with inner cracks was an open system far from the balanced state. The dissipative structure was produced during thermal healing due to the nonlinear condition for reaction diffusion, energy fluctuation, structure fluctuation and composition fluctuation.