Super-Austenitic Stainless Steels

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Super austenitic stainless steel consists of a Pitting Resistance Equivalent Number that is larger than 40, and is allocated to alloys with huge amounts of molybdenum. This stainless steel is the most extensively utilised in the realm of stainless steels in general engineering applications. In particular, the 3xx series is quite easy to fabricate and weld and boasts of tremendous strength across various temperatures and a decent amount of corrosion resistance. This is a stainless steel that also consists of soaring levels of nickel along with molybdenum and nitrogen, further showing up as different austenities coupled with greater strength than conventional 300 series stainless along with great levels of resistance to pitting, stress corrosion cracking and crevice corrosion.

With a significant rise in the amount of chromium and molybdenum present, resistance can be enhanced to pitting corrosion. In an attempt to preserve the good mechanical and physical properties of austenitic stainless steel, there needs to be a rise in the nickel content. This, in turn, results in increase in the prices, shifting most of the interest towards alternative grades. The most commonly used super austenitic stainless steel is Alloy 254.

In order to cope with austenitic intergranular corrosion sensitivity after welding, tantalum were added as carbide stabilizing elements. After the invention of AOD and VOD refining techniques in the 1960s, carbon content in austenitic stainless steel was reduced drastically. Steel purity got better with the new technique, while it also solved the problem of intergranular corrosion sensitivity after welding.

Features of Super-Austenitic Stainless Steel

1) It has one among the most demanding technical requirements.
2) It is hard to melt, easy to separate and crack.
3) Austenitic stainless steel is high in molybdenum and nickel.
4) It contains nitrogen and copper elements.
5) It features good cold and hot workability.


1) Pulp, paper bleaching equipment, such as bleaching equipment.
2) Off-shore systems or seawater treatment, such as thin-walled condensing pipes.
3) Heat exchangers, particularly those working under a chloride ion environment.
4) Power plant flue gas desulfurization device. The parts used: door panel and sprinkler system.


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