Study on Fracture Toughness Testing Technique of High Strength and Toughness Alloy

Based on that there exist unapplicable problems for high strength and toughness alloy in national and international fracture toughness testing standards (GB, ASTM and BS), a set of methods were presented and recommended for amendment of the standards.The relationship between critical thickness B_C of large scale yielding and Young's modulus (E) was established for high strength and toughness alloy.Specially, the errors of K_IC by the J_IC conversion formula was analyzed.Finally, the optimal parameters of single specimen method are determined by the orthogonal test method.