高强度桥梁用宽厚板断裂韧性分析

Analysis of the Impact Properties of 500MPa Heavy Plates for Bridge

利用示波冲击试验及断口分析的方法对500MPa级桥梁用钢的断裂韧性进行了研究。结果表明：随着温度的降低，冲击总能量Wt和裂纹扩展能量Wp均在减小，裂纹形成能量Wi变化不明显，试样钢的韧一脆转变温度约在-40℃左右。随着温度的降低，材料的断裂方式由最初的韧性断裂转变为胞】生断裂，断裂机理由微孔聚集的韧窝断裂转变为穿晶解理断裂。

The impact properties of heavy plates for birdge have been investigated by means of instrumented impact test and SEM. The results show that the Wt and Wp decrease with the decrease of temperature, while the Wi change is not regular- ly, and the ductile--to--brittle facture transition temperature of the plates is 40℃. As the temperature decrease, the fracture mode changes from the ductile frature to the brittle fracture, and the fracture mechanism changes from the dimple fracture to the transgranular cleavage fraetre.