ASME SA 240 S31254 Stainless Steel Plate Ultra SMO254 UNS S31254 Metal Plate

254 SMO Super Austenitic Stainless Steel  Plate 

UNS S31254

254 SMO stainless steel bar, also known as UNS S31254, was originally developed for use in seawater and other aggressive chloride-bearing environments. This grade is considered a very high end austenitic stainless steel; mainly comprised of between 19.5% and 20.5% chromium, 17.5% to 18.5% nickel, 6% to 6.5% molybdenum and .18% to .22% nitrogen. These specific levels of Cr, Ni, Mo, and N in this “super austenitic” chemical makeup allow 31254 to combine impact toughness resistance to corrosion cracking, with pitting and crevice corrosion resistance. The result is strength of nearly twice that of 300 series stainless steels.

UNS S31254 is often referred to as a “6% Moly” grade due to the molybdenum content; the 6% Moly family has the ability to withstand high temperatures and maintain strength under volatile conditions. This grade has surpassed its original intent and overlapped into many industries proving useful owing to its high level of molybdenum amount other elements, which allows 31254 to be used successfully in various applications such as Flue gas desulfurization and Chemical environments.

Industries that use 31254 include:

• Chemical
• Desalination
• Flue gas desulfurization
• Food processing
• Pharmaceutical
• Pulp and Paper

Products partially or completely constructed of 31254 include:

• Chemical processing equipment
• Desalination equipment
• Flue gas desulfurization scrubbers
• Food processing equipment
• Heat exchangers
• Hydrometallurgy
• Oil and gas production equipment
• Pulp mill bleach systems
• Seawater handling equipment
• Tall oil distillation columns and equipment

Common Applications for 254SMO

254SMO is used frequently in the following applications –

• Equipment in pulp bleaching plants
• Components in gas cleaning systems
• Equipment for handling seawater, such as heat exchangers, ballast water systems, firefighting systems
• and cooling water systems.

254SMO and other super austenitics have been specified for marine scrubbers, as their intermittent use can result in operating temperatures >250degC. However, super duplex stainless steels have been successfully used in flue gas desulphurization systems for power stations, as continuous operation results in lower temperatures. Super austenitics such as 254SMO have been substituted by super duplex stainless steels in water treatment systems, such as RO/desalination.