The basic composition of austenitic stainless steel is 18% C, 8% Ni, referred to as 18-8 stainless steel. In order to adjust the corrosion resistance, mechanical properties, process performance and reduce the corrosion resistance, Mn, Cu, N, MO, Ti, N6 and other alloying elements are often added to austenitic stainless steel, thus developing the 18-8 type stainless steel. Many new steel books, species. Austenitic stainless steel has good weldability, low-temperature toughness and non-magnetic properties. It is characterized by a low carbon content of 0.1%. It uses C and Ni to obtain a single-phase austenite structure. It has good cold deformation ability and is relatively stable. With high corrosion resistance and plasticity, it can be cold drawn into very fine steel wires, cold drawn into very thin steel strips or steel pipes. Later, after a large amount of deformation, the strength of the steel was greatly improved because in addition to the cold work hardening effect, deformation-induced martensitic transformation was also added. Austenitic stainless steel has good resistance to uniform corrosion, but there are still some problems in resisting local corrosion. The main problems in the welding of austenitic stainless steel are intergranular corrosion of welded joints, stress corrosion cracking of welded joints, hot cracking of welded joints, etc. . 3. Austenitic stainless steel welding method There are many welding methods for austenitic stainless steel, such as manual welding, gas shielded welding, submerged arc welding, plasma welding, etc. The most commonly used welding method is manual welding (MMA), followed by metal arc arc welding (MIGMAG) and tungsten inert gas welding (TIG). This article takes manual arc welding and tungsten arc welding, which are most commonly used in pipeline installation and construction in the petrochemical industry, as examples to briefly describe the precautions during welding construction. 1. Manual arc welding is the most commonly used welding method for welding austenitic stainless steel plates with a thickness of more than 2 mm. Because the heat of arc welding is relatively concentrated and the heat affected zone is small, the welding deformation is small; it can adapt to various welding positions and different plate thickness process requirements, and the equipment used is simple. 2. Tungsten electrode argon gas shielded welding is an ideal welding method for welding austenitic stainless steel. Because the argon gas protection effect is good, the alloy element transition coefficient is high, and the weld composition is easy to control; because the heat source is concentrated, the linear energy during welding is very small, and there is argon gas cooling effect, the welding heat affected zone is narrow, the weld strength and It has excellent plasticity and toughness, does not require slag cleaning after welding, and can be welded in all positions and mechanized welding. Although austenitic stainless steel still has many shortcomings, its advantages are still worthy of our in-depth understanding and application. Only by being good at applying the advantages and cleverly avoiding the shortcomings can we better discover and apply new materials and new processes. . To learn more, please visit the website: www.baowi-steel.com