Use of a Ring DWTT Specimen for Determination of Steel NDT from Pipe of Diameter Less than DN500

• Published in: Journal of failure analysis and prevention Vol. 16; no. 6; pp. 941 - 950
• Main Authors: Ben Amara, M, Capelle, J, Azari, Z, Pluvinage, G
• Format: Journal Article
• Language: English
• Published: Materials Park Springer Nature B.V 01-12-2016; Springer Verlag
• Subjects: Crack propagation; Crack tips; Diameters; Drop weight tests; Ductile fracture; Ductile-brittle transition; Ductility; Ductility tests; Energy; Engineering Sciences; Fracture mechanics; Fracture toughness; High strength low alloy steels; Mechanical engineering; Mechanics; Mechanics of materials; Nondestructive testing; Pipe; Pipes; Propagation; Steel; Steels; Tearing; Temperature; Transition temperature; crack extension; constraint; Ring specimen; NDT
• ISSN: 1547-7029; 1864-1245; 5555-1313
• DOI: 10.1007/s11668-016-0194-y

It has become recognized that the drop weight tearing test (DWTT) energy better represents the ductile fracture resistance of pipe steels since it utilizes a specimen that has the full thickness of the pipe and has a fracture path long enough to reach steady-state fracture resistance. However, the API 5L code does not require it for pipe sizes less than DN500. The aim of this paper is to propose a DWTT specific to small diameter pipes based on a new specimen, the ring drop weight tearing test (RDWTT) specimen; to evaluate the transition temperature T t, DWTT and nil ductility temperature of the pipe steel API 5L X65; to introduce the transition temperature T t, DWTT in the transition temperature material master curve of the API 5L X65 steel; and to compare the prediction of the crack ductile extension in a pipe based on the RDWTT's energy and crack tip opening angle in the case of the steel API 5L X65.