Use of COD as a measure of fracture initiation in steel pressure vessels

Conference · Mon Jan 01 04:00:00 EST 1973

OSTI ID:4397709

Kirby, N; Ingham, T; Cowan, A

From 2nd international congress for pressure vessel and piping technology; San Antonio, Texas, USA (1 Oct 1973). See CONF731003-P2. Tests to failure on 1 in. thick wide plates and cylindrical pressure vessels containing through thickness defects have been used to demonstrate the range of validity of crack opening displacement (COD) as a fracture concept. Tests on steels with yield strengths ranging from 33,000 to 71,000 psi yield strength have shown that close correspondence is obtained between the failure stresses in defected wide plates and pressure vessels with those predicted from the COD determined in bend tests. As the COD in the bend test becomes greater, failure is preceded by stable ductile tearing and prediction of failure conditions becomes increasingly more inaccurate but at these toughnesses leak before break'' conditions are probable. The effect of thickness on material toughness was investigated in tests on two 3 in. thick pressure vessels. In the vessel geometry used, the opposing effects of thickness on fracture toughness and rigidity may be isolated, with that of toughness predominating at the lower temperatures. (auth)

• Research Organization: United Kingdom Atomic Energy Authority, Risley, Eng.
• NSA Number: NSA-29-000334
• OSTI ID: 4397709
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

*PRESSURE VESSELS-- FAILURES
*STEELS-- FRACTURE PROPERTIES
CRACKS
DEFECTS
N42400* --Engineering--Materials Testing
N50230 --Metals
Ceramics
& Other Materials--Metals & Alloys--Properties
Structure & Phase Studies
N79200 --Reactors- -Reactor Components & Accessories
PLATES
TEMPERATURE DEPENDENCE
THICKNESS