from the conferences organized by TANGER Ltd.
Since thermomechanical treatments favors increased mechanical resistance characteristics of steels, their degree of alloying is lower than that of any found in normalized steel with the same strength.This is extremely beneficial for the weldability of steel.To prevent the emergence of unwanted micro-structural transformations in welded joint areas (softening HAZ, excessive growth of grain, cold cracking), the present paper aims to implement the narrow gap MAG welding of steel X65M intended for the fabrication of pipeline used for the transportation of natural gases and liquid hydrocarbons.Root and hot layers have been welded using MAG spray arc and the fill layers in pulsed current.The equipment used is composed by an internal welding machine for the root pass and external one with two welding torches for the fill layers, where the pipe is fix and the welding equipment make an downward vertical orbital movement around the pipe.Assessments of the quality of the welds are done through macro- and micrographic analyzes in conjunction with sclerometer examinations.
Keywords: thermomechanical treatment, steel, MAG welding, narrow gap.© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.