What are the surface treatment processes of Duplex Stainless Steel 2304?
What are the surface treatment processes of Duplex Stainless Steel 2304?
Duplex Stainless Steel 2304, also known as SAF 2304, is a duplex stainless steel with the characteristics of austenitic and ferritic stainless steels. Here are some possible surface treatments:
Solid solution treatment: This is a common heat treatment process for duplex stainless steel. It is heated to a certain temperature and then quickly cooled to obtain a balanced austenite and ferrite structure, thereby improving the overall performance of the material.
Aging treatment: Aging treatment is the process of changing the microstructure and properties of materials by keeping them at a certain temperature for a period of time. For SAF2304, studies have shown that aging treatment at different temperatures (such as 600 to 800 degrees Celsius) can affect its microstructure and corrosion resistance.
Pickling: This is a chemical treatment method that removes oxide layers and other contaminants from the surface of stainless steel, improving the surface finish and corrosion resistance.
Polishing: Mechanical or chemical polishing can be used to improve surface finish, reduce the possibility of corrosion, and give stainless steel surfaces a good appearance.
Coating: In some applications, to improve corrosion and wear resistance, SAF 2304 may be coated with a protective film, such as a ceramic coating or other high-performance coating.
Passivation treatment: This is a surface treatment method that improves corrosion resistance by forming a thin, dense oxide film on the metal surface.
In general, the selection and application of these treatment processes depends on the use environment and performance requirements of the final product. For example, real sea exposure experiments show that the surface of SAF 2304 can form a dense metal oxide film in the early stage of exposure. As time goes by, a relatively dense calcium magnesium deposition layer and SiO2 will be attached to the oxide film. These layers are combined with stainless steel. It is tight and has a certain protective effect, making the corrosion rate much lower than that of carbon steel, showing good corrosion resistance. Therefore, these characteristics as well as the specific requirements of the actual application should be taken into account when selecting a surface treatment process.
