Estimation Of Q345r Fracture Toughness Based On Master Curve

1T CT specimens are used to evaluate the fracture toughness of Chinese Q345R steel in the ductile-brittle transition regime by Master Curve method. Tensile tests, Charpy impact tests and drop-weight tests of Q345R steel are also carried out to get the ductile-brittleness transition temperature and nil-ductility transition temperature. Master Curves are compared with the empirical formulas adopted in ASME, API and BS codes. Results show that the reference temperature To values derived from single-temperature and multi-temperature method by 1T specimen are basically consistent. Master Curve can well envelop the fracture toughness and temperature curves derived from the empirical formulas, and is more economic and flexible than the K-IC curve with sufficient conservation.