| 2015 №02 (10) |
DOI of Article 10.15407/tpwj2015.02.01 |
2015 №02 (02) |
The Paton Welding Journal, 2015, #2, 2-6 pages
CONCERNING REQUIREMENTS TO IMPACT TOUGHNESS OF JOINTS OF PIPELINES PRODUCED USING FLASH BUTT WELDING
V.I. Kyrian, S.I. Kuchuk-Yatsenko And B.I. Kazymov
E.O. Paton Electric Welding Institute, NASU. 11 Bozhenko Str., 03680, Kiev, Ukraine. E-mail: office@paton.kiev.ua
Abstract
To provide serviceability of joints of pipelines produced using flash butt welding (FBW) alongside with the condition of strength the requirement to impact toughness KCV is set forth. Its level is established according to the requirements to the joints produced using arc welding methods, for which the probability of appearance of crack-like defects in them is peculiar. Absence of even preconditions to formation of cracks in the FB-welded joints allows initiating the review of requirements to impact toughness. As the standard level the KCV value is offered, which is reliably provided at optimum mode of FBW performance. The sufficiency of such KCV level is proved by reliable many-years practice in operation of different-purpose pipelines without fractures, including main pipelines of large diameter (up to 1420 mm). For the given KCV value at the working circumferential stresses in the pipeline and axial ones equal to half of their value, the critical sizes of hypothetic through longitudinal and circumferential cracks are calculated. Their sufficient sizes prove in appropriateness of such approach. 20 Ref., 3 Figures.
Keywords: flash butt welding, typical defects of FBW, impact toughness, requirements, critical sizes of hypothetic cracks
Received: 13.11.14
Published: 01.04.15
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