输电铁塔用Q460角钢低温断裂韧性研究

Research on Fracture Toughness of Q460 Equal-leg Angles Used in Transmission Tower

采用三点弯曲试验,研究了输电铁塔用Q460角钢在低温下的断裂韧性。不同钢厂、不同规格Q460角钢的试验结果表明,温度越低,厚度对CTOD值影响越大,且厚度的增加会降低钢材韧性,促使钢结构更容易发生脆断。不同批次的Q460角钢,常规力学性能和断裂韧性有较大差别,且角钢的屈服强度对断裂韧性有一定影响,为此,应控制高强角钢屈服强度的上限。

The fracture toughness of Q460 steel used in transmission tower was studied by three-point bending test at low temperature. The result about different specification and different steel show that the lower the temperature is, the greater the impact of thickness on CTOD value is, and increasing the thickness can reduce the toughness of steel. The steel was more susceptible to brittle fracture. Conventional mechanical properties and fracture toughness is very different and the yield strength has a certain impact on the fracture toughness for different batches of angle steel. So it is important that upper limit of yield strength of high-strength angle steel should be controlled.