| 2006 №03 (01) | 2006 №03 (03) |
The Paton Welding Journal, 2006, #3, 7-10 pages
Accelerated induction heat treatment of welds on pipes from controlled-rolled steels
S.I. Kuchuk-Yatsenko, A.S. Pismenny, M.E. Shinlov, B.I. Kazymov, V.F. Zagadarchuk
E.O. Paton Electric Welding Institute of the NASU. 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine.Abstract
Process of heat treatment (HT) at a comparatively short-term intensive action of the electromagnetic field on the welds made by flash-butt welding was studied. HT modes and mechanical properties of the treated and control welds are considered. It is established that application of accelerated intensive induction HT, envisaging a short-term increase in weld temperature above Ac3 point, leads to an increase in the index of weld impact toughness, narrowing of the heating zone, as well as saving of the energy consumed in HT. At weld HT duration of 90 to 180 s for steels of X65 and X80 grades, values of weld metal impact toughness are increased up to the required level, while the weld metal strength decreases by not more than 3.6 and 7.0 %, respectively. Accelerated induction HT can be used for improvement of impact toughness of weld metal in joints of large diameter pipes.
Keywords: induction heat treatment, line pipelines, controlled-rolled steels, weld, impact toughness, accelerated treatment
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