Characterization of Dissimilar Welded Joints Between Austenitic and Duplex Stainless Steel Grades for Liquid Tank Applications

Abstract

Lean duplex stainless steels have similar corrosion and better mechanical properties than the austenitic grades, which ensure their extensive spreading in industrial applications as a substitute of austenitic grades. In the construction of liquid tanks, however, it is often necessary to weld such steels with a range of fittings which are commonly fabricated with austenitic stainless steel grades. Therefore, this paper examines dissimilar welded joints between LDX 2101 (or X2CrMnNiN22-5-2) lean duplex stainless steels plates and austenitic stainless steel pipes, carried out by different arc welding processes. The investigation focuses on the correlation between the welding procedures and the microstructural and mechanical properties of the welded joints.

Kinetics of Intermetallic Phase Precipitation in Manual Metal Arc Welded Duplex Stainless Steels

“…A typical microstructure of the γ phase (austenite) distributed in the matrix of the δ phase (δ-ferrite) was observed. An analogous structure after hot rolling of lean duplex LDX2101 steel was observed by G. Ubertalli et al [34], F. Iacoviello et al [35], W. Gong et al [36], F. Tehovnik [37] or S. Gudikandula, and A. Sharma [38]. Changes in the microstructure after annealing at 800 °C are shown in Figure 2.…”

“…There is little information about microstructure changes in the heat-affected zone of LDX2101 steel and much less information about the influence of annealing. Analysis of microstructure changes in the heat-affected zone presented in the work of Ubertali et al [34] confirmed the occurrence of precipitates of chromium nitrides Cr 2 N at the δ/γ interphase boundaries in the post-welded state. The occurrence of nitrides was also reported by Sun in [44].…”