Basic properties and composition characteristics of 254SMO/S31254 steel

254SMO (corresponding to UNS number S31254) is a typical 6Mo type super austenitic stainless steel, developed by Avesta of Sweden in 1978. It has extremely high corrosion resistance and is especially suitable for halide and acidic environments.

Carbon (C): The carbon content is very low (≤ 0.02%), which helps to improve the material's welding performance and intergranular corrosion resistance.

Manganese (Mn): The manganese content is controlled at ≤ 1.00%, which helps to improve the material's strength and toughness.

Silicon (Si): The silicon content is ≤ 0.80%, which helps to improve the material's oxidation resistance.

Phosphorus (P) and Sulfur (S): The phosphorus and sulfur contents are controlled at ≤ 0.03% and ≤ 0.01%, respectively, to reduce the material's brittleness and improve welding performance.

Chromium (Cr): Chromium content is 19.5-20.5%, which is a key element to improve the corrosion resistance of materials

Implementation standards:

ASTM A240/ASME SA-240, ASTM A276, ASTM A182/ASME SA-182, ASTM A312/ASMES A312

Physical properties:

254SMO density: 8.24g/cm3, melting point: 1320-1390 ℃, magnetism: none

Mechanical properties:

Tensile strength: σb≥655Mpa, yield strength σb≥310Mpa: elongation: δ≥35%, hardness: 182-223 (HB)

Corrosion resistance characteristics

Local corrosion resistance: High molybdenum content (6-6.5%) makes it have excellent resistance to pitting and crevice corrosion, especially in high concentration chloride ion environment (such as seawater, bleaching liquid).

Uniform corrosion resistance: In acid medium containing halides, the corrosion resistance is better than ordinary stainless steel such as 316L, and it can withstand non-oxidizing acids such as sulfuric acid and phosphoric acid.

Environmental adaptability: Good resistance to sulfides in seawater, flue gas desulfurization environment, and stress corrosion cracking (SCC) under high temperature and high humidity conditions.

Core application industries

1. Marine engineering: seawater desalination equipment, marine structures, seawater heat exchangers, and seawater aquaculture facilities.

2. Environmental protection and energy: thermal power generation flue gas desulfurization equipment, wastewater treatment systems, atomic power generation equipment, and tidal power generation components.

3. Petrochemicals: oil refining equipment, chemical reactors, pipelines, valves, flanges, and exhaust gas desulfurization scrubbers.

4. Food and papermaking: salt making equipment, soy sauce brewing equipment, pulp bleaching systems, and high-concentration chloride ion bleaching equipment.

5. Other fields: brine treatment, heat exchangers, water pumps, chokes, and food processing machinery parts.

Material form and supply

1. Spot form: plates (such as 1.0mm thick coils), bars, welding materials (matching ERNiCrMo-3 welding wire, ENiCrMo-3 welding rods), flanges, forgings, seamless pipes, fasteners, etc. can be customized.

2. Processing technology: It needs to be produced through cold rolling, cold drawing, solution annealing and other processes, with a tolerance control accuracy of up to 0.02mm and an inner and outer wall roughness of ≤0.4μm.