冲击功与COD转变温度的相关关系

对普通C-Mn钢,Cr-Mo钢和三种焊缝金属进行了系列温度示波冲击试验,COD试验和屈服强度的测定,通过对实验结果的分析发现,中低强结构钢和焊缝金属的冲击韧性和断裂韧性的延脆转变温度之间存在着统一的相关关系,即试验材料的两韧性的延脆转变温度迁移量与材料的应变速率敏感性呈线性关系。因此,推荐了工程上用冲击韧性推测断裂韧性的方法,并指出这一相关关系存在的内在原因是不同试验材料的缺口冲击试样和裂纹静载试样在延性断裂过程、解理的力学条件以及解理微观机制这三个方面的相似性。

A Correlation Between Transition Temperatures of Absorbed Energy and Fracture Toughness,COD

In this research work, the instrumented Charpy impact tests the COD tests, and the mearurement of yield strengths are carried out on C-Mn steels,Cr-Mo steel,and three kinds of weld metals under various test temperatures. It is found through the analysis of the test results that there is a unified correlation between the ductile-brittle transition temperatures of Charpy absorbed energy and those of fracture toughness both for low and medium strength steels and weld metals, this correlation is a linear relationship between the transition temperature shift of the two toughnesses and the strain rate sensitivities of the test materials,according to which a method is proposed for engineering practice to estimate the fracture toughness of the material from information obtained by Charpy impact tests. It is also pointed out that the inherent reason of the existence of this correlation is the similarity of different materials in three aspects;the ductile fracture processes,the mechanical condition and the micromecha-nism of cleavage after the fibrous crack extension during fracture, no matter what type of specimens is used,the V-notched impact or precracked slow bending.