摘要
采用SEM检测了TWIP钢动态拉伸后的组织形态。结果发现,TWIP钢具有典型的延性断裂断口特征,其变形和断裂过程为微孔洞的形核、长大和聚合。含有第二相的TWIP钢的断裂机制为:第二相和奥氏体相界面聚合力的减弱或第二相本身加工硬化导致的开裂促使微孔形核,形变过程中产生的应力集中使微孔长大、聚合直至发生断裂。全奥氏体的TWIP钢的断裂机制为:形变过程中位错的运动受孪晶界的阻碍,形变孪晶与位错的交互作用使微孔形核于孪晶界处,应力集中使微孔长大、聚合直至材料发生断裂。
The microstructure of TWIP steels after dynamic tension test was observed by SEM. It was found that the fracture of TWIP steel was typical ductile fracture pattern and its deformation and fracture processes were the formation, growth and coalescence of microvoids. The fracture mechanism of TWIP steel which contained second phase was that the microvoids nucleated due to the decreasing of binding force between austenite and second-phase or the second phase dehiscence caused by strain hardening, then the microvoids grew, got together and broke by the stress concentration during deformation. The fracture mechanism of the whole austenite TWIP steel was that the moving of dislocations was blocked by twin boundary during deformation, the microvoids nucleated at boundary of deformed twins by the interaction between deformed twins and dislocations, the microvoids grew, got together and broke by the stress concentration during deformation.
出处
《上海金属》
CAS
2008年第5期12-15,共4页
Shanghai Metals
基金
先进钢铁材料技术国家工程研究中心科技发展基金
国家自然科学基金资助项目(50671061)
