Research engineer, Westinghouse Research Laboratories, Westinghouse Electric Corporation, Pittsburgh, Pa.
Pages: 18 Published: Jan 1976
Good agreement was found between elastic plastic (JIc) and previously developed conventional linear elastic (KIc) critical fracture toughness values for five materials. The materials investigated included four rotor forging steels (ASTM A471 Ni-Cr-Mo-V, ASTM A469 Ni-Mo-V, ASTM A470 Cr-Mo-V, and AISI 403 modified 12Cr) plus an ASTM A217 21/4Cr-1Mo cast steel. A resistance curve test technique recently developed by Landes and Begley was employed to obtain the JIc fracture toughness values. Elastic plastic fracture toughness tests were performed with 1-in.-thick compact tension specimens at a minimum of three temperatures per material, the highest temperature being that where upper shelf fracture toughness behavior was first expected. The fine agreement between the elastic plastic and linear elastic critical fracture toughness values for this class of steels further supports the realization that the elastic plastic JIc fracture criterion, based largely on the path independent J-integral proposed by Rice, extends the concepts of linear elastic fracture mechanics into the elastic plastic fracture regime. Thus, it is now possible to obtain critical fracture toughness values with small specimens over a wide range of temperatures for tough materials.
crack propagation, fracture strength, mechanical properties, steels, fracture tests, stress analysis
Paper ID: STP33938S