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How Is Stainless Steel 254 Smo Manufactured?

The stainless steel 254 SMO material is an austenitic high-alloy stainless steel for use in seawater, pulp and paper industries, brackish water, and other harsh chloride-bearing environments. With the specific amounts of Cr, Ni, Mo, and N in this chemical composition, 31254 has the ability to combine impact toughness resistance to corrosion cracking, pitting resistance, and crevice corrosion resistance to provide a chemical composition that is nearly twice as strong as stainless steels of the 300 series.

stainless steel SMO 254 pipes

It is common for UNS S31254 to be known as a "6% Moly" grade due to its high molybdenum content; in addition, it can maintain strength in volatile environments at high temperatures and keep its strength indefinitely. The grade has exceeded its original intent and has crossed over into many industries as a result of the high level of molybdenum and other elements, enabling it to be used successfully in a variety of applications such as flue gas desulfurization and chemical environments owing to its high molybdenum content, among other things. In some applications, it has even been found to be a more cost effective substitute for high nickel and titanium alloys because it possesses the same performance characteristics.

There are a number of Swiss and European standards for high quality stainless steels, but SMO 254 is a high end stainless steel that is designed specifically to offer increased strength, toughness, corrosion resistance, and an increased resistance to chloride corrosion.

As a stainless steel grade, SMO 254 products have highly desirable physical properties. These include a density of 8 g/cm3 metric, 0.289 lb/in3 imperial and a fluidity of 10 g/cm3.

254 SMO plate

A SMO 254 Round Bar has physical and chemical properties that make it suitable for use in extreme conditions such as seawater and chloride-based applications due to the fact that its chemical properties allow it to be used under such conditions. We offer SMO 254 Pipes for oil distillation columns, food processing equipment, bleaching equipment, and more, since they are all annealed, pickled, cold drawn, and polished according to requirements. These are the most commonly used pipes in the industry today. 

The SMO 254 grade content of all the products possesses outstanding welding properties, despite the fact that they require filler materials to be added to the material so that the strength is maintained. 

There is a danger that these products may scale when too much heat is applied over a temperature range of 982-1142 degrees Celsius, which in turn affects their workability. 

The materials which can be cold worked will exhibit a greater level of strength and toughness as a result of post-process annealing, which also helps preserve the maximum corrosion resistance provided by the material. Cold working these materials is challenging, but it is possible to do so in accordance with all the conventional methods.

The SMO 254 pipe fittings and flanges are an effective alternative to high nickel and titanium alloys used for a range of different applications. They are designed to offer great workability and increased connectivity to pipes, making them a cost effective alternative. Moreover, they have a longer service life in the refining industry, from low pressure applications to high pressure applications. As a result of the high molybdenum content combined with nickel and copper in SMO 254 Sheets & Plates, the corrosion resistance will be very high and they can resist setting and fissure erosion in situations with bromide, chloride, and fluoride solutions, for example. As a result, they have become a preferred option over the 300 series for sea water applications, marine systems, and closed circle water frameworks.

It is estimated that the thermal expansion coefficient for this grade between the temperatures of 20 C and 100 C or 68 C and 212 F is 16.5 m/m at 0 C, or 9.17 mm at 0 F in imperial. In addition, thermal conductivity for this grade is 14 W/mK at 0 F, or 97.2 BTU per hour. 0 F. In spite of this, hardening these materials can only be accomplished by cold reduction because they are not quite receptive to heat treatment.

Stainless Steel 254Smo Properties And Processing Characteristics

  • A high resistance to pitting and crevice corrosion, with a PRE of 42.5. (A PRE is defined as the weight-percentage based on the following formula: Pre = %Cr + 3.3x %Mo + 16x %N.)
  • The product is highly corrosion resistant on a general basis
  • Stress corrosion cracking resistance is very high with this product
  • In comparison to conventional austenitic stainless steels, this stainless steel has higher strength
  • Having good weldability is one of the most important factors

The Stainless Steel 254 Smo Plates, Pipes, Fasteners & Forgings Can Be Used In A Wide Range Of Applications

  • Handling saltwater in a marine environment
  • There are tall columns used for distilling oil
  • Sulfur dioxide scrubbers used in flue gas desulfurization
  • The components that are used in the production of petroleum
  • A food processing machine is an item used for processing foods
  • The chemical industry utilizes a variety of process equipment to do its job
  • There are a number of equipments used in the pulp and paper industry for bleaching
  • Cleaning of flue gases is one of the most important steps
  • Providing desalinated water
  • Exchangers of heat

Stainless Steel 254 Smo Fabrication Data & Other Properties

Totally avoid abrasion of copper/copper alloys and other similar metals which, if present in metallic form, can cause cracks when welded, heated, or subjected to heat treatment during additional steps of the process.

254 SMO sheets
  • Machinability

There is no sulfur content in stainless steel grade alloy 254 smo , so it is very hard to machine. However, sharp tools, well-powered machine tools, positive feeds, sufficient amount of lubrication, and slow speeds are all good ways to ensure that machining results are good, even with this high level of work hardening rate and low sulfur content.

  • Bending

190 Millimeters can successfully be forged from 254 SMO tube due to its excellent formability, which allows it to be cold forged to very fine bending radiuses. Annealing is typically not required after cold bending.

  • Welding

There is a requirement for filler material to be used when welding stainless steel grade 254 SMOTM because it results in poor strength properties without it. Filler metals such as AWS A5.14 ERNiCrMo-3, and alloy 625 are highly recommended. Electrodes must be select in accordance with AWS A5.11 ENiCrMo-12.

  • Annealing

A water quench should do follow the annealing of this material at a temperature of 1149-1204°C (2100-2200°F), after which the material should be quenched in water.

  • Hot Working

At 982 – 1149°C (1800 – 2100°F), this material can be forged, upended or other operations. The material is recommended not to be exposed to temperatures higher than this range, as this could result in scaling and a reduction in workability. It is recommended that post-process annealing be done to regain maximum corrosion resistance.

  • Cold Working

There is no need to use any specific method to cold work materials, but it will be a challenging procedure due to the high work hardening rate, which will boost the strength and toughness of the material.

  • Hardening

Cold reduction is the only way to harden stainless steel grade 254 SMOTM. Heat treatment cannot be used to harden the material.

  • Forging

Considering the high alloy content of the material, the recommended forging temperature range is 2370/1920oF (1300/1050oC), followed by a minimum solution anneal temperature of 2100oF (1150oC).

Properties Of Stainless Steel 254 Smo In Corrosion Resistance

  • The high chromium, molybdenum, and nitrogen content of the alloy makes it highly resistant to pitting and crevice corrosion.
  • Having a very low carbon content, there is very little chance of carbide precipitating when the item is heated, so it is ideal for heating food
  • In spite of the fact that it has good resistance to chlorides in water, it is, therefore, ideal for use in seawater since it can withstand prolonged exposure to it without suffering from crevice corrosion due to its high degree of resistance.