1.4547 stainless steel chemical Composition

 

EN 1.4547 is a super austenitic stainless steel, also known as UNS S31254 or 254 SMO, containing high levels of chromium, nickel, and molybdenum. It exhibits excellent resistance to pitting corrosion, crevice corrosion, and stress corrosion cracking, especially in highly corrosive, chloride-rich environments such as seawater. Compared to standard stainless steels like 316L, it offers higher strength and superior corrosion resistance. It is suitable for use in marine, chemical, and pulp and paper industries.

 

 

1.4547 stainless steel (also known as 254 SMO, UNS S31254, F44, 6Mo, or X1CrNiMoN20-18-7) is a super austenitic stainless steel with high levels of chromium, nickel, and molybdenum, giving it excellent resistance to pitting, crevice corrosion, and stress corrosion cracking, especially in chloride-rich environments like seawater, making it a high-performance alternative to common grades like 316L in demanding conditions.

 

 

1.4547 Chemical Composition (% By Weight)

Title	UNS	Werkstoff	C	Si	Mn	P	S	Cr	Ni	Mo	Cu	N
6mo	S31254	1.4547	<0.02	0.7	1	0.03	0.01	20	18	6.1	0.75	0.2

 

1.4547  Physical Properties (Room Temperature)

Specific Heat (0-100°C)	500	J.kg-1.°K-1
Thermal Conductivity	14	W.m -1.°K-1
Thermal Expansion	16.5	μm/μm/°C
Modulus Elasticity	196	GPa
Electrical Resistivity	8.5	Ohm-cm
Density	8.0	g/cm3

 

1.4547 Mechanical Properties

Temper	Annealed
Tensile Rm	98	ksi (min)
Tensile Rm	675	MPa (min)
R.p. 0.2% Yield	45	ksi (min)
R.p. 0.2% Yield	310	MPa (min)
Elongation (2" or 4D gl)	35	% (min)

 

1.4547  Heat treatment:

Forging	1200 to 950 °C
Welding	weldable with all common welding processes
Annealing	Solution annealing at at least 1150 °C, followed by water quenching
Stress relieving annealing	at approx. 500°C
Hardening	no

 

1.4547 Stainless Steel – Corrosion Resistance
1.4547 stainless steel (commonly known as 254 SMO) offers exceptional corrosion resistance, especially in chloride-rich and seawater environments, with a very high PREN value of ~42–45 driven by its ~20% Cr, ~18% Ni, ~6% Mo, and nitrogen addition, delivering outstanding resistance to pitting, crevice corrosion, and stress corrosion cracking where standard 316L fails.

 

Is 1.4547 Stainless Steel Magnetic?
1.4547 is non-magnetic in the solution-annealed condition due to its fully austenitic microstructure; however, slight magnetism may develop after heavy cold working, which does not compromise its corrosion resistance.

 

1.4547 Stainless Steel – Machinability
1.4547 has lower machinability than 316L because of its high alloy content and strong work-hardening behavior, typically rated at ~30–35% of free-cutting steel, requiring rigid tooling, low cutting speeds, and effective cooling to achieve stable machining performance.

 

What is the difference between 1.4404 and 1.4547?

1.4404 (316L) is a general-purpose low-carbon austenitic stainless steel, while 1.4547 (254 SMO) is a high-alloy super austenitic stainless steel containing higher levels of molybdenum (Mo) and nitrogen (N), suitable for extreme chloride/acidic environments and offering superior resistance to pitting and crevice corrosion. However, 1.4404 is less expensive and easier to weld/form. In short, 1.4404 is a general-purpose material, while 1.4547 is a specialized material.

 

 

If you have project requirements for 1.4547 stainless steel, we welcome your order. GNEE has a large inventory of popular products for you to choose from. It can be processed into various practical product forms, including plates, coils, tubes, bars, wires, etc. For detailed chemical composition information and free samples, please contact our factory immediately. We offer competitive prices and excellent service.Email: info@gneestainless.com

Testing and Documentation: Factory test certificate, EN 10204 3.1, chemical report, mechanical report, destructive testing report, non-destructive testing report, PMI test report, visual inspection report, third-party inspection report, NABL certified laboratory report.
Packaging: Wooden crate packaging, bubble wrap packaging, steel strapping, or packaging according to customer requirements.