高强结构钢Q420低温断裂韧性研究

针对不同板厚的高强结构钢Q420角钢进行了不同温度下的断裂韧性试验，计算得出了试样的裂纹尖端张开位移指标。试验结果表明，温度对结构钢材的断裂韧性具有明显的作用，钢材的断裂韧性随着温度的降低显著减小，断裂方式也由延性断裂转变为脆性断裂。总体趋势上来讲，试样厚度的增大也引起钢材断裂韧性的降低。因此，在重要工程设计、选材及安全分析时,应充分考虑温度和厚度对结构断裂行为告白影响。

Research on Fracture Toughness of High-strength Structural Steel Q420 at Low Temperature

The fracture toughness of high-strength structural steel Q420 with different thickness was studied by three-point bending test.The crack tip opening displacement values were calculated.The results indicated that the temperature had significant influence on fracture toughness of structural steel and the fracture toughness was reduced significantly with the decrease of temperature resulting to brittle fracture.Generally,the increase of specimen thickness also caused the decrease of fracture toughness of structural steel.Thus,the effects of temperature and the thickness should be considered in the important engineering design,material selection and safety analysis.