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Super austenitic stainless steel

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Release time:2014-07-31

When the pitting resistance value of Cr-Ni austenitic stainless steel (Pren =[Cr]+3.3[Mo]+16[N]) ≥40%, it can be called super austenitic stainless steel. Super austenitic stainless steel is mainly developed to solve the problems of the original high molybdenum (>4%) chromium-nickel austenitic stainless steel in the harsh corrosion conditions containing Cl-, such as pitting corrosion resistance, crevice corrosion resistance and poor thermal stability of the structure. The emergence of super austenitic stainless steel has filled the gap between chromium-nickel austenitic stainless steel and high nickel corrosion resistant alloy without high pitting resistance and high crevice corrosion resistance stainless steel.

The biggest characteristic of super austenitic stainless steel performance is that in harsh corrosive environment, this kind of steel pitting corrosion resistance, crack corrosion resistance performance is excellent, not only far better than all the original austenitic stainless steel, but also with some well-known nickel-based corrosion alloy to be comparable.

Super austenitic stainless steels are divided into 6%Mo type and 7%Mo type, which were developed in the 1970s and 1990s respectively.

Due to the high content of chromium, molybdenum and nitrogen in super austenitic stainless steel, the difficulties in the production and use of this kind of steel in metallurgical plants are as follows: the control of high nitrogen during smelting; Poor thermoplasticity of steel, mastering the hot working process; In the process of hot working, heat treatment and welding, the brittleness phase such as χ (σ) is easy to prevent from precipitation. (From Introduction to Stainless Steel)