桥梁高性能钢HPS485W断裂韧性试验研究

为了研究桥梁高性能钢的断裂韧性，对中国舞阳钢厂生产的高性能钢HPS 485W进行了一系列的断裂韧性试验研究。通过夏比V形缺口冲击试验得到HPS 485W在不同温度下的冲击韧性，并应用Boltzmann函数求解韧脆转变温度曲线，试验结果表明：与传统桥梁用钢相比，HPS 485W冲击韧性更高且韧-脆转变温度更低。由HPS 485W延性断裂韧度(J_IC)试验，测得板厚18mm和28mm的HPS 485W试样的J积分值，试验结果表明HPS 485W具有优良的断裂韧性。对8mm和14mm的HPS 485W进行裂纹尖端张开位移(CTOD)试验，试验结果表明HPS 485W有良好的塑性和韧性。基于HPS 485W拉伸试验获得的应力-应变曲线结果，运用失效评定曲线方法对CTOD试验值进行评定，HPS 485W的母材断裂韧性(CTOD)落在评定曲线的合格范围内。该文的研究为高性能钢桥的安全评定和防断裂设计提供了试验依据。

FRACTURE AND TOUGHNESS TETS STUDY OF HIGH PERFORMANCE STEEL HPS 485W FOR BRIDGE ENGINEERING

To study the fracture behavior of high performance steel for bridge engineering, a series of fracture toughness tests were conducted for high performance steel HPS 485W, which was produced by Wuyang Steel Company in China. The toughness at different temperature was obtained from HPS 485W Charpy V notch toughness test, and the ductile to a brittle curve was fitted using a Boltzmann function. Charpy V notch toughness test shows that HPS 485W, compared with traditional steel, is characterized with higher toughness and lower brittle-ductile transition temperature. After the ductility fracture toughness (J_IC ) test, the calculated Jvalues were obtained for 18mm and 28mm thick specimens, which shows good fracture toughness of HPS 485W. Crack tip opening displacement (CTOD) tests were conducted for 8mm and 14mm HPS485W specimens. CTOD test results show the good plasticity and toughness of HPS485W. Based on the stress and strain curve obtained from a tensile test for HPS485W, a failure assessment diagram was used for evaluation. The evaluation results show that the CTOD test result belonges to an acceptable field. Fracture toughness tests proposed in this paper are helpful in the safety assessment and fracture control of HPS bridges.