通过改变晶界形态强化晶界是改善多晶耐热合金高温强度晨有效的途径之一。对于奥氏体耐热钢,锯齿形晶界可阻止晶界裂纹的发生与扩展,但对具体的强化机制尚不完全清楚。本文认为,锯齿形晶界的强化作用是由于阻碍晶界滑移引起的,尤其对高温下常见的晶界破坏起重要作用。随着晶界滑移长度的减小,连接于三个方向晶界的交界点(称三重点)的应力集中程度降低,发生延性的沿晶断裂。分析 It is one of the effective ways to improve the high temperature strength of polycrystalline heat-resisting alloy by changing grain boundary morphology and strengthening grain boundaries. For austenitic heat-resistant steel, zigzag grain boundaries can prevent the occurrence of grain boundary cracks and expansion, but the specific strengthening mechanism is not yet fully understood. This paper argues that the strengthening effect of zigzag grain boundaries is due to obstructing the grain boundary slip caused, especially for high temperature common grain boundary damage plays an important role. With the decrease of the slip length of the grain boundary, the stress concentration at the junction (called the triple point) connected to the grain boundaries in the three directions decreases and the ductile intergranular fracture occurs. analysis