1.4547 material equivalent

What is 1.4547 material?

1.4547 material is a super austenitic stainless steel, also known by its UNS S31254 and 254 SMO designations, that is highly resistant to corrosion, particularly in chloride-rich environments like seawater. It features a high content of molybdenum, nickel, and chromium, giving it exceptional resistance to pitting and crevice corrosion, as well as good strength and resistance to stress corrosion cracking. Common applications include seawater handling systems, desalination plants, and chemical processing equipment.

 

What is the equivalent of stainless steel 1.4547?

Equivalents of 1.4547 stainless steel include UNS S31254, 254 SMO, and ASTM F44. Due to its high molybdenum content, it is also known as 6MO.

 

1.4547 Stainless Steel Chemical Properties

		C	Si	Mn	S	N	Cr	Cu	Mo	Ni	P
1.4547	Min %					0,18	19,50	0,50	6,00	17,50
	Max %	0,020	0,70	1,00	0,010	0,25	20,50	1,00	7,00	18,50
S 31254	Min %					0,18	19,50	0,50	6,00	17,50
	Max %	0,20	0,80	1,00	0,010	0,22	20,50	1,00	6,50	18,50	0,030
ASTM A 312 (S 31254)

1.4547 Stainless Steel 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 Stainless Steel 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	μohm/cm
Density	8.0	g/cm3

 

254 smo stainless steel Machinability

254 SMO stainless steel is quite tough to machine due to the extremely high work hardening rate and lack of sulfur content; however using sharp tools, overpowered machine tools, positive feeds, good amount of lubrication, and slow speeds tend to provide good machining results.

 

Annealing

Annealing of this material should be performed at 1149-1204°C (2100-2200°F), which should be followed by a water quench.

 

What is the difference between 1.4547 and 1.4410 stainless steel?

The main difference is that 1.4547 (Super Austenitic Stainless Steel 254 SMO) is a high-alloy austenitic stainless steel with higher molybdenum content and higher PREN, offering exceptional resistance to pitting and crevice corrosion, while 1.4410 (Super Duplex Stainless Steel 2507) is a super duplex steel with a two-phase (austenite and ferrite) structure, providing higher strength and good overall corrosion resistance.