用示波落锤试验法评价14MnVTiRe钢的韧脆断裂行为
Evaluation of Tough-brittle Fracture Behaviors of 14MnVTiRe Steel by Using Instrumented Drop-weight Tester
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摘要: 采用示波落锤试验法对5mm热连轧14MnVTiRe钢的韧脆断裂行为进行了研究并对落锤撕裂试样的动态断裂特征进行了评价。结果表明,当裂纹扩展功远大于裂纹萌生功时,试样处于韧性断裂状态;当裂纹扩展功小于裂纹萌生功时,试样处于脆性断裂状态;当裂纹扩展功与裂纹萌生功相当时,试样处于混合断裂状态。该结果与按标准测定的剪切面积百分数有良好的对应关系,说明示波落锤试验法可作为一种评定材料韧脆断裂特征的实用方法。Abstract: By using instrumented drop-weight tester, the dynamic fracture behavior of the thermal continuous rolling 5mm 14MnVTiRe steel plate was investigated and the evaluation of fracture characteristic of drop-weight tear specimen was conducted. The results showed that tough fracture will occur when crack propagation energy is much higher than initial energy and brittle fracture will occur when crack propagation energy is lower than initial energy and mingled fracture will occur when crack propagation energy is equivalent to initial energy. The result obtaining from drop-weight tear test is well in correspondance with that obtaining from fracture surface measure manifesting that drop-weight tear test could be employed as one of practical measure to evaluate the tough and brittle fracture behavior of materials.