Stainless steel can be divided into four categories according to organization: austenitic stainless steel, ferritic stainless steel, martensitic stainless steel and duplex stainless steel. The production and use of austenitic stainless steel account for about 70% of the total stainless steel output and are the most important stainless steel grades. Austenitic stainless steels generally contain more of Cr and Ni. Compared with other stainless steels, in addition to excellent corrosion resistance, austenitic stainless steels also have biocompatibility, good formability and weldability, good plasticity and toughness, and are non-magnetic. It is a very good material. Therefore, it is widely used in many fields such as petrochemical industry, biomedicine, food, marine and so on. Austenitic stainless steel has many advantages, but there are often defects that affect the performance of the material during the welding process, such as severe intergranular corrosion, stress corrosion, and thermal cracking in the welded joint. Once these defects occur, the service life of the equipment will be affected during the use process, causing potential safety hazards. Researchers have put forward measures to reduce or prevent defects based on the analysis and discussion of the defects that often occur in the austenitic stainless steel welding process. It has important significance and reference value for improving the service life of austenitic stainless steel and expanding its application field. There are many factors that affect the welding quality of cast bushing suppliers austenitic stainless steel, mainly including materials, processes and environment. Intergranular corrosion is the most susceptible problem in the welding process of stainless steel. By adjusting the percentage content of C in the welding material and the base material, and adding the ferrite forming element appropriately, under the proper welding conditions and correct welding Under treatment, this kind of defect can be basically avoided. The carbon content of austenitic stainless steel is very low, and about 1% of Ti is added to the steel as a stabilizer to suppress the formation of Cr carbides, thereby eliminating the tendency of intergranular corrosion of steel. Material stress corrosion cracking is the damage caused by the joint action of stress and corrosion environment, so measures can be taken from the environment and stress to prevent the occurrence of stress corrosion. On the one hand, changing the corrosion environment in contact with the material is an effective measure to prevent stress corrosion. On the other hand, reducing or eliminating residual stress is another effective measure to prevent stress corrosion. The occurrence of stress corrosion is mainly due to the low thermal conductivity and high linear expansion coefficient of austenitic stainless steel. The increase of the annealing process after welding reduces the probability of its occurrence. The welding process is improved, while avoiding contact with corrosive solutions containing halogen and controlling the oxygen content in the solution. The thermal cracking of austenitic stainless steel is mainly affected by the alloy composition, metallographic structure and welding stress. Therefore, it can be controlled by adjusting the alloy composition of the welding material, controlling the existing metallographic structure and using a suitable welding process. The embrittlement of stainless steel can be avoided and improved by adjusting the alloy composition. Taking appropriate measures from the aspects of materials and processes will greatly improve the service life of austenitic stainless steel, which has important economic significance.
