Twin-Wire Pulsed Tandem Gas Metal Arc Welding of API X80 Steel Linepipe

Abstract

Twin-Wire Pulsed Tandem Gas Metal Arc Welding process with high welding production efficiency was used to join the girth weld seam of API X80 steel linepipe of 18.4 mm wall thickness and 1422 mm diameter. The macrostructure, microstructure, hardness, and electrochemical corrosion behavior of welded joints were studied. Effects of temperature and Cl − concentration on the corrosion behavior of base metal and weld metal were investigated. Results show that the welded joint has good morphology, mechanical properties, and corrosion resistance. The corrosion resistance of both the base metal and the weld metal decreases with increasing temperature or Cl − concentration. In the solution with high Cl − concentration, the base metal and weld metal are more susceptible to pitting. The corrosion resistance of the weld metal is slightly lower than that of the base metal.

Evaluation of the Properties and Microstructure of Thick-Walled Welded Joint of Wear Resistant Materials

“…The welded joint was made under automated conditions as a V butt joint with a groove angle of 45° using the MAG PULSE and MAG TANDEM welding processes [ 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. The MAG PULS welding process was used in the area of the first four reverse-side beads, while the rest of the weld groove was filled using the high-performance TANDEM version of the MAG process.…”

“…The high-performance MAG TANDEM is a two-electrode process with an independent power supply for each electrode [ 22 , 23 ]; it allows the achievement of much higher welding efficiency compared to the conventional single-electrode process [ 26 , 27 ]. The welding tests were carried out using the Cloos equipment.…”