高温长期运行Cr-Mo钢断裂性能微试样测试实验研究

SMALL PUNCH TEST FOR DETERMINING THE MATERIAL PROPERTIES OF Cr-Mo STEEL AFTER LONG-TERM SERVE AT HIGH TEMPERATURE

开展采用小冲杆微试样试验技术评定材料断裂性能的研究。针对2.25Cr-1Mo钢(脆化态和脱脆态)及1.25Cr-0.5Mo钢,将小冲杆试验测试结果与常规冲击韧度及断裂韧度试验结果相关联,得到小冲杆试样变形过程中消耗的总变形能与常规夏比冲击功间的对应关系经验公式,以及小冲杆试样等效断裂应变与材料延性断裂韧度间的关联式,说明可以直接采用小冲杆试验结果估算材料的冲击及断裂韧度值,为无法取标准试样进行材料抗断裂性能测试场合提供了一种可行的间接测试技术。

Fracture resistance ability of materials is studied by small punch test technique. 2.25Cr-1Mo （as received and de-embrittled） and 1.25Cr-0.5Mo steels are under investigation. By associating the result of small punch test and that of conventional fracture toughness test, the empirical formula on the whole energy absorbed during distortion of small punch specimen and conventional Charpy impact absorbed energy is established. The relation between equivalent fracture strain of small punch specimen and fracture toughness is also identified. It is concluded that the impact and fracture toughness of material can be estimated by the result of small punch test, which provide a feasible indirect measurement technique to test fracture toughness of materials in the situation of unfeasibility of standard- ized sampling.