Study On The Welding Process And Corrosion Resistance Of2205Duplex Stainless Steel

With the development of the national economy, the transport of goods by rail wagons showing the diversity of features, performance of railway wagons also put forward higher requirements. In recent years, more and more new materials, such as high weathering steel, stainless steel, aluminum alloy, widely used in the manufacture of Railway Vehicle, railway wagons significantly improve the performance.2205duplex stainless steel has excellent overall performance, such as high strength, high impact toughness and corrosion cracking is not sensitive,then widely used in petrochemical, sea water and waste water treatment, oil gas and other industries. But the duplex stainless steel less used in the Railway vehicles, because its welding process is a difficult problem faced by the vehicle manufacturing. Therefore, to research the2205duplex stainless steel welding technology, optimize the welding process, ensure that welded joints have good mechanical properties and corrosion resistance is so important for China in duplex stainless steel’s study, production, and wide application.In this article,2205duplex stainless steel plate welded with a large amount of welding parameters under the principle of obtaining reasonable austenitic/ferrite ratio of two phases. Two welding method include MAG and SMAW, for MAG welding use different welding heat input and different types of shielding gas ratio to detect different welding process on the properties and structure of duplex stainless steel welded joints. Stretching, bending, hardness test, micro shear and the proportion of two-phase test is carried out on the welded joints obtained test to verify whether the mechanical properties of the connector to meet the standard requirements. And select the base metal and three of the welding joints which both qualified of bending and back bending to do the pitting test, to test the corrosion resistance of welded joints.Experimental results show that each joint tensile strength, hardness values have reached the standard requirements, the individual sample due to the presence of welding defects caused by the back bending failed; austenite content increases along with the increase in weld heat input, but the thermal input caused by large heat-affected zone grain coarsening general joint poor impact toughness; N2as a protective gas in welding, the mechanical properties, corrosion resistance can be optimum; the pitting resistance of base metal and the weld are up to the requirements of ASTM G48, the corrosion rate with corrosion concentration increases.