Austenitic stainless steel is widely used in the manufacture of compaction vessels, boilers, and nuclear power equipment because of its good corrosion resistance, plasticity and turnability. Taking pressure vessels as an example, this type of equipment has a large number of applications in the fields of new energy, medicine, and food processing. For example, in the field of new energy, tankers, tankers and tankers used to store low-temperature gases such as liquid oxygen, liquid nitrogen and liquefied natural gas Strain strengthened container. Pressure vessel sterilization cabinets used for high-temperature sterilization of medical devices in the medical field, and fermentation tanks used for beer brewing in the food field. It can be seen that austenitic stainless steel pressure vessels and their corresponding parts have huge demands in production and life. As an important component of large-scale equipment such as pressure vessels and boilers, the heads of the heads increase with the growth of the demand for pressure vessels, boilers and other equipment, which has higher requirements for the mass production of heads and product quality.

　　In engineering, austenitic stainless steel is divided into stable austenitic stainless steel and metastable austenitic stainless steel. Among them, low-priced metastable austenitic stainless steels are often used in the manufacture of pressure vessels, such as SS304. At present, standard oval heads are widely used in medium and low pressure vessels. Such heads are often produced by stamping or spinning processes. Compared with spinning process, stamping is more suitable for mass production. However, metastable austenitic stainless steel undergoes deformation and martensitic transformation during the head stamping process, which will affect the mechanical properties of the head material, and even cause the failure of the head, causing safety hazards. Based on this status, the stamping process of the standard elliptical head made of metastable austenitic stainless steel is studied.

　　Head stamping process

　　Stamping process

　　Head stamping can be divided into cold stamping and hot stamping according to whether the board is heated. The stamping process on the work roll is divided into cold stamping, hot stamping and warm stamping according to whether the heating humidity is higher than the recrystallization temperature of the material. Among them, the heating temperature of hot stamping is higher than the refining temperature, and the heating temperature of wet stamping is between the suffocation temperature and the recrystallization temperature, but there is no uniform boundary. This is also the focus of research. The three stamping processes are composed of five stages and are roughly the same. The details of each stage are as follows:

　　(1) Material warehousing inspection: After the material enters the factory, the head factory will re-inspect the steel plate in accordance with GB24511-2009 and corresponding enterprise standards to determine its yield strength, tensile strength, elongation after fracture, chemical composition and hardness Whether the indicators meet the requirements.

　　(2) Blanking and cutting: The company cuts the sheet material through plasma cutting machine, circular shearing machine, etc. to obtain the circular sheet material required for stamping

　　(3) Press forming

　　(4) Groove forming

　　(5) Head quality inspection After cutting the bevel, the stamping head shall undergo non-destructive welding seam inspection, surface pickling and polishing.

　　Both cold and hot stamping processes have their shortcomings, and the warm stamping process heats the wool core between room temperature and recrystallization temperature. This method combines the advantages of cold and hot stamping Wang Yi: due to the higher deformation temperature, the martensitic transformation induced by the deformation is limited, so compared to the cold stamping head, the straight edge section of the warm stamping head The amount of martensite is low; compared to hot stamping heads, warm stamping heads require lower heating temperature and lower cost.