Mechanical Properties and Microstructure of Austenite-Ferrite Duplex Stainless Steel Hybrid (Laser + GMAW) and SAW Welded Joint

• Published in: Materials Vol. 16; no. 7; p. 2909
• Main Authors: Krawczyk, Ryszard, Słania, Jacek, Golański, Grzegorz, Pfeifer, Tomasz
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 06.04.2023; MDPI
• Subjects: Austenitic stainless steels; Butt joints; Butt welding; Cooling; Corrosion resistance; Destructive testing; Duplex plating; Duplex stainless steels; duplex steel; Electrodes; Energy; Ferrite; Ferritic stainless steels; Gas metal arc welding; Heat affected zone; HLAW + SAW welded joint; Impact tests; Iron compounds; Laser beam welding; Lasers; Mechanical properties; Microstructure; Nondestructive testing; Power supply; Reagents; Stainless steel; Submerged arc welding; Technology application; Tensile strength; Thick plates; Weld metal; Welded joints; Welding; duplex steel; microstructure; HLAW + SAW welded joint; mechanical properties
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma16072909

The purpose of the research was to develop a technology for producing thick-walled duplex steel welded joints. The material used in the research was X2CrNiMoN22 duplex steel in the form of a 15 mm thick plate. The welded joint was produced by the modern, high-performance Hybrid Laser Arc Welding (HLAW) method. The HLAW method involves welding a joint using a laser, the Gas Metal Arc Welding (GMAW) method and the Submerged Arc Welding (SAW) method. The HLAW method was used to make the root pass of the double butt welded joint, while the filler passes were made by the SAW method. The obtained welded joint was subjected to non-destructive and destructive testing. The non-destructive and macroscopic tests allowed the joint to be classified to the quality level B. Microscopic examinations revealed the presence of ferritic-austenitic microstructure in the base material and the weld, with different ferrite content in specific joint areas. The analysed joint had high strength properties (tensile strength (TS) ~ 790 ± 7 MPa) and high ductility of weld metal (~160 ± 4 J) heat-affected zone (~216 ± 26 J), and plasticity (bending angle of 180° with no macrocracks). At the same time, hardness on the cross-section of the welded joint did not exceed 280 HV10.