Super Stainless Steel and nickel-based alloys are special varieties of stainless steel. First, it differs chemically from ordinary stainless steel. It refers to high alloy stainless steel containing high nickel, high chromium, high molybdenum.
According to the microstructure characteristics of stainless steel materials, super stainless steel is divided into super ferritic stainless steel, super austenitic stainless steel, super martensitic stainless steel, super duplex stainless steel and other types.
Super austenitic stainless steel
On the basis of ordinary austenitic stainless steel, by improving the purity of alloy, increasing the number of beneficial elements, reducing the content of C, prevent the precipitation of Cr23C6 caused by intergranular corrosion, obtain good mechanical properties, process properties and local corrosion resistance, replace Ti stable stainless steel.
Super ferritic stainless steel
It inherits the characteristics of high strength, good oxidation resistance and excellent stress corrosion resistance of ordinary ferritic stainless steel. At the same time, it improves the limitations of ferrite stainless steel in the welding state of brittle transition, sensitive to intergranular corrosion and low toughness. Ultra-ferritic stainless steel with high Cr, Mo and ultra low C and N can be obtained by refining technology, reducing the content of C and N, adding stabilizing and welding metal toughening elements. The application of ferritic stainless steel in corrosion resistance and chloride corrosion resistance has entered a new stage.
Super duplex stainless steel
The steel was developed in the late 1980s. The main brands are SAF2507, UR52N, Zeron100, etc., which are characterized by low C content, high Mo content and high N content. The ferritic phase content in steel accounts for 40% ~ 45%. , with excellent corrosion resistance.
Super martensitic stainless steel
It is a hardenable stainless steel with high hardness, strength and wear resistance, but poor toughness and weldability. Ordinary martensitic stainless steel lacks enough ductility, is very sensitive to stress when deformed, and is difficult to form in cold working. By reducing the carbon content and increasing the nickel content, super martensitic stainless steel can be obtained. In recent years, countries have invested a lot of money in the development of low carbon and low nitrogen super martensitic steel, and developed a batch of super martensitic steel for different purposes. Super martensitic steel has been widely used in oil and gas exploitation, storage and transportation equipment, hydropower, chemical industry, high temperature pulp production equipment and other fields.
Functional stainless steel
With the change of market demand, a variety of stainless steel with special uses and special functions continue to emerge. Such as the new medical nickel free austenitic stainless steel material is mainly Cr-Ni austenitic stainless steel, has good biocompatibility, containing Ni 13% ~ 15%. Nickel is a kind of sensitizing factor, which is teratogenic and carcinogenic to organisms. Prolonged use of implanted nickel-containing stainless steel gradually destroys and releases Ni ions. When Ni ions are enriched in tissues near implantation, toxic effects can be induced and adverse reactions such as cell destruction and inflammation can occur. Cr-Mn-N medical nickel-free austenitic stainless steel developed by Institute of Metal Research, Chinese Academy of Sciences has been tested for biocompatibility, and its performance is better than that of Cr-Ni austenitic stainless steel in clinical use. Another example is antibacterial stainless steel. With the improvement of people’s living standard, people pay more and more attention to the environment and their own health, which promotes the research and development of antibacterial materials. Since 1980, developed countries represented by Japan began to study and apply antibacterial materials in household appliances, food packaging, daily necessities, bath equipment and other aspects. Nissin Steel and Kawasaki Steel developed antibacterial stainless steel containing cu and ag, respectively. Copper antibacterial stainless steel is added in stainless steel 0.5% ~ 1.0% copper, after special heat treatment, so that the stainless steel from the surface to the inside of the uniform. Dispersing ε-Cu precipitates play an antibacterial role. This copper containing antibacterial stainless steel is suitable for a range of products such as premium kitchenware, as well as other products with high requirements for processing properties and antibacterial properties.
Post time: Feb-16-2023