一前言断裂韧性K_■反映了金属材料阻碍裂纹扩展和抵抗断裂的能力,它是材料固有属性的量度。因此,Klc 是作衡量材料抗断裂性能的一个重要指标。测定金属材料断裂韧性的标准方法有三点弯曲和紧凑拉伸两种方法。应用这两种方法需要疲劳试验机,动态电阻应变仪,X—Y 记录仪等昂贵的测试设备和复杂的测试技术,不便于在生产中推广。此外,就K_(lc)本身而言,由于裂纹扩展除了与材料内部条 I. INTRODUCTION FRACTURE TOUGHNESS K_ ■ reflects the ability of metallic materials to retard crack propagation and fracture resistance and is a measure of the inherent properties of the material. Therefore, Klc is an important indicator of material fracture resistance. The standard method for determining the fracture toughness of metallic materials is three-point bending and compact stretching. The application of these two methods requires expensive testing equipment such as fatigue testers, dynamic resistance strain gauges, X-Y recorders, and sophisticated testing techniques, which are inconvenient to promote in production. In addition, K_ (lc) itself, due to crack propagation except with the material inside the bar