A study on fracture toughness of structural steels

A STUDY ON FRACTURE TOUGHNESS OF STRUCTURAL STEELS ABSTRACT In this study, fracture toughness of structural steels having a bcc crystal structure dependence with different mechanical properties are considered, obtaining possibility of high fracture toughness is investigated. Metallic materials experience fracture damage by the advancing crack growth which leeds to the failure of parts. Enhanced fracture toughness of the steels was aimed through developing microstructure and mechanical properties of the steels. In this study, materials of fracture micromechanism are investigated. A comparison between ASTM E-399 standard, COD and J-integral methods and the method used are given. Some heat treatments on 4140, 8620, 1040 and 1050 steels are performed. The change in fracture toughness in relation to heat treatment regimes are also inestigated. A program was developed for calculation of fracture toughness with MATLAB. Anahtar Kelimeler: Fracture Toughness, Fracture Micromechanism, Heat Treatment, MATLAB n