Duplex stainless steel has high strength, good corrosion resistance and welding performance, and has become an important material for the pressure vessel industry. Especially in solving the problems of stress corrosion and pitting corrosion encountered in traditional austenitic stainless steel, it has significant advantages. According to the characteristics of the pressure vessel industry, duplex stainless steel has been successfully applied in reactors, towers, heat exchangers, tube sheets, etc. in petrochemical, oil refining, coal chemical and other fields.
The head is an important equipment of the pressure vessel. The material not only requires good corrosion resistance and weldability, but also has good spinning formability. Duplex stainless steel has a high yield strength and strong resilience when the head is formed; at the same time, the elongation is low (generally 25% to 30%), and a larger bending radius and necessary intermediate annealing are required.
Plate heat exchangers are becoming more and more popular because of their high efficiency, compactness, and low metal consumption. They are generally divided into two types: fully welded and detachable. At present, duplex stainless steel has been successfully applied in this field. The thickness of the all-welded type material is generally 2.0mm, and the thickness of the detachable type is 0.6-0.8mm. Compared with the two, the latter corrugated plate has stricter requirements on the cold formability of duplex stainless steel. Practice has proved that due to the high strength of duplex stainless steel, the r value (plastic strain ratio) of 45° is higher than that of 0° and 90°, which makes it more favorable for the analysis of new materials to withstand complex forming conditions.
