49 Rapid and Low Cost Method to Determine the Plane Strain Fracture Toughness (K_Ic) in Hydrogen

This paper introduces a rapid and low cost method to accurately determine the plane strain fracture toughness (K_Ic) of materials in a hydrogen environment using a cylindrical notched tensile (CNT) specimen. If the notch tip radius of the specimen is made sharp enough, the fatigue pre-cracking procedure for the notch is not required. The proposed CNT specimen could possibly be the simplest and smallest fracture specimen to produce a valid plane strain loading condition relative to the industry test standard using a compact tension (CT) specimen. This paper highlights several advantages of the CNT specimens for determining both the hydrogen embrittlement effects on the notched tensile strength and also on the K_Ic values.