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本文测定了C-Mn钢母材,C-Mn和Ti-B焊缝金属在不同温度下的Charpy V,COD和预制裂纹冲击试验中的断裂载荷、韧性值和断口上纤维裂纹长度,同时也测定了这些材料的力学性能。结果表明COD裂纹试样的局部解理断裂应σ_f比Charpy V 缺口试样高约600MPa。在试验温度区内,控制韧性的因素是断裂载荷、纤维裂纹长度和单位纤维裂纹扩展能量。母材较低的屈服应力σ_y,较强的σ_y对载荷速度的敏感性和较低的σ_f,使其Charpy V脆性转变温度高于焊缝,COD脆性转变温度低于焊缝。还对各韧性试样断裂行为的差别与建立Charpy V和COD结果之间关系的条件也进行了讨论。
In this paper, the fracture load, toughness value and the length of fiber crack on the fracture of C-Mn steel base metal, C-Mn and Ti-B weld metal at different temperatures under Charpy V, COD and pre-crack impact were measured, The mechanical properties of these materials were measured. The results show that the local cleavage fracture of COD cracked specimen should be about 600MPa higher than that of Charpy V notched specimen. In the test temperature zone, the factors controlling the ductility are the breaking load, the length of the fiber crack and the energy of the fiber crack propagation per unit. The lower yield stress σ_y of the base metal, the stronger sensitivity of σ_y to the loading speed and the lower σ_f make the Charpy V brittle transition temperature higher than that of the weld, and the brittle transition temperature of COD is lower than that of the weld. The conditions for establishing the relationship between Charpy V and COD results were also discussed for the differences in the fracture behavior of the ductile samples.