Effects of Fabrication Flaws on Crack Initiation and Arrest Properties of 9 Percent Nickel Steel Used in LNG (Liquefied Natural Gas) Storage Tanks. Final Report March 1982-December 1985

摘要

During LNG tank construction, weld discontinuities (flaws) are sometimes unintentionally produced within welded joints. The project was part of an international effort to assess the effects of these discontinuities upon crack initiation propagation, and arrest in 9 percent nickel steel. This was undertaken because doubt persists regarding whether sufficient testing of 9 percent nickel has been carried out to assure LNG tank safety. In order to accomplish the goals of the project, the research included (1) the preparation of a bibliography detailing the discontinuities commonly associated with welding, (2) conducting parent plate characterization tests, (3) development of methods for the laboratory production of weld flaws, (4) performance of crack arrest tests, and (5) an assessment of the effect of different weld heat inputs on the fracture energy of standard Charpy V-notch specimens.