Metallurgical investigation of electron beam welded duplex stainless steel X2CrNiMoN22-5-3 with plasma nitrided weld edge surfaces

Abstract

Duplex stainless steel is common in thick-walled components such as longitudinal welded pipes in the oil and gas industries and as parts of various machines in the chemical and food industries. Electron beam welding is a very suitable method for welding such components. Due to the high power density of the electron beam combined with the decreased evaporation temperature in a vacuum atmosphere, steel with a sheet thickness of up to 150 mm can be welded in one pass. In the case of the electron beam welding of duplex stainless steels, vacuum atmosphere in the working chamber causes a nitrogen effusion from the weld pool. The microstructure of the resulting weld is characterized by an unacceptable high ferrite content, which is the main reason for both low impact toughness and low pitting corrosion resistance. This work focuses on the influence of nitrided weld edge surfaces on metallurgical properties of the resulting welded joint. The aim here is to investigate the effect of increased nitrogen content at the weld edges on nitrogen loss during EB-welding. The welds produced within the experimental work were characterized by means of microstructural analysis and the use of optical and energy dispersive X-ray spectroscopy. It was shown that nitrided weld edge surfaces can compensate nitrogen loss from the weld pool and decrease the ferrite content in the resulting weld.

Electron beam welding of 2205 duplex stainless steel with nickel-based filler wire using multi-beam technique

“…This frequently occurs in laser beam welding but also in arc welding processes when solely argon protects the weld pool [12,14,15]. In electron beam welding, the partial pressure of the nitrogen is obviously practically zero as a high-vacuum is utilized [16][17][18]. Since nitrogen is a very strong austenite stabilizer, its loss impedes the formation of austenite during cooling.…”

Effects of Flowrate of Additional Shielding Gas on the Properties of Welded Seam by Twin-wire GMAW Welding for Duplex Stainless Steel

“…Enhancement of welding productivity to achieve welding automation and improve welding quality had become a crucial issue in the development of welding technology [1][2][3][4][5]. Twin-wire GMAW welding technology could achieve high speed welding and good deposition rate and so, had received much popularity as well as research attention at home and abroad [6][7][8][9][10]. The welding effect of twin-wire double-pulsed GMAW welding was affected by several parameters such as voltage, current, welding wire, base metal, and welding speed; especially the welding speed that directly determined the welding production efficiency.…”

Investigation on the microstructural and mechanical properties of electron beam welded 2507 duplex stainless steel joint

“…In electron beam welding (EBW), which is a widely used process for thick sections [7], a signi cant fraction of the nitrogen escapes the weld pool due to high-vacuum which technically reduces the partial pressure of the nitrogen to zero. As nitrogen is a strong austenite stabilizer, its loss greatly contributes to a mostly ferritic microstructure in the weld metal (WM) in all welding processes even when the cooling time is comparably high [8][9][10]. Nitrogen effusion also occurs in laser beam welding (LBW) if the shielding gas does not contain nitrogen.…”