Alloy 254SMO WS 1.4547 UNS S31250 Stainless Steel

Alloy 254SMO WS 1.4547 UNS S31250 Stainless Steel

254SMO is a grade of stainless steel;
UNS S31254 is its international designation;
German standard designation: W.-Nr. 1.4547;
Forging grade: F44;
Commonly known as: 6Mo steel.

Product Description

The overall corrosion resistance of 254SMO falls between that of ordinary stainless steel and nickel-based alloys, making it a highly cost-effective metal material. Its domestic equivalent is 00Cr20Ni18Mo6CuN.

This Stainless Steel Grade 254 SMO highly corrosion-resistant super austenitic stainless steel was developed for environments involving halides and acids; it is widely used in demanding conditions such as media with high chloride ion concentrations and seawater. In various industrial applications involving acidic media—particularly acids containing halides— Alloy 254SMO WS 1.4547 UNS S31250 Stainless Steel significantly outperforms other stainless steels, and in some instances, its performance rivals that of Hastelloy and titanium alloys.

Performance Characteristics—-Alloy 254 Stainless Steel

Corrosion resistance

High levels of elements such as molybdenum, chromium, and nitrogen provide excellent resistance to pitting, crevice corrosion, and stress corrosion cracking in environments such as seawater, media with high chloride ion concentrations, and acidic solutions.

High strength

Possesses high strength and hardness, capable of withstanding significant mechanical loads.

Processability

Can be formed and processed by conventional metal processing techniques, such as forging, rolling, cutting, etc.

Weldability

It can be welded using various techniques and retains good properties after welding.

Chemical Composition—-STAINLESS STEEL 254SMo
C: ≤0.02;
Si: ≤0.7;
Mn: ≤1;
P: ≤0.03;
S: ≤0.01;
Cr: 19.5–20.5;
Ni: 17.5–18.5;
Cu: 0.5–1;
Mo: 6–7;
N: 0.18–0.25;

Physical Properties—-254SMO

Density: 8.24 g/cm³

Melting Point: 1320–1390°C

Coefficient of Thermal Expansion: 15.7 μm/m/°C (100°C to 300°C)

Thermal Conductivity: 14.5 W/m·°C (20°C)

Specific Heat Capacity: 500 J/kg·K

Mechanical Properties

Yield Strength: ≥310 MPa

Tensile Strength: ≥650 MPa

Elongation: ≥35%

Hardness: ≤210 HB

Study on Crevice Corrosion Behavior of 254 SMO Super Stainless Steel in a Simulated Flue Gas Desulfurization Environment.

Due to its high content of Cr, Mo, Ni, and N, 254SMo exhibits strong resistance to pitting and crevice corrosion, making it suitable for acidic, chloride-containing environments such as flue gas desulfurization units.