engleski

Laser welding of duplex stainless steel with different shielding gases

In the laser welding of duplex stainless steel approximately equally proportions of ferrite and austenite in the two-phase structure are disturbed. High cooling rates result in the creation of an augmented proportion of ferrite in the welded joint, which results in the reduction of corrosion resistance and deterioration of the mechanical properties, and particularly impact toughness and deformability. The choice of shielding gas can affect the structure of the welded joint. The paper discusses the welding of duplex steel W.Nr.1.4462 2 mm thick with the use of the Nd:YAG laser. The welding parameters and the influence of the kind of shielding gas are investigated. As shielding gases, argon, helium and nitrogen are used. The following were investigated: the structure, geometry, hardness, strength, deformability and the resistance of the welded joint to the phenomenon of pitting corrosion. High quality welds were obtained without the appearance of cracks. The effect of the shielding gases on the structure, hardness and corrosion resistance of the welded joint was shown to be significant, while the influence on geometrical form, strength and deformability was not shown to be significant

laser beam welding; weldability; duplex stainless steel; shielding gas

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