AISI 444 Stainless Steel Material Data Sheet (Ferritic, Annealed)

AISI 444 Designation

AISI 444, wrought
Condition	Annealed
UNS number	S44400
US name	ASTM S44401, ASTM S-44400, ASTM 444
EN name	X2CrMoTi18-2
EN number	1.4521
GB (Chinese) name	00Cr18Mo2
JIS (Japanese) name	SUS444TP, SUS444

AISI 444 Typical uses

Cutting edges, marine applications

AISI 444 Composition detail

C (carbon)	0	–	0.025	%
Cr (chromium)	17.5	–	19.5	%
Fe (iron)	74.1	–	80.6	%
Mn (manganese)	0	–	1	%
Mo (molybdenum)	1.75	–	2.5	%
N (nitrogen)	0	–	0.035	%
Nb (niobium)	0.1	–	0.4	%
Ni (nickel)	0	–	1	%
P (phosphorus)	0	–	0.04	%
S (sulfur)	0	–	0.03	%
Si (silicon)	0	–	1	%
Ti (titanium)	0.1	–	0.4	%

AISI 444 Physical properties

Density

7.7

–

7.9

g/cm3

AISI 444 Mechanical properties

Young’s modulus	195	–	205	GPa
Specific stiffness	24.9	–	26.4	MN.m/kg
Yield strength (elastic limit)	275	–	350	MPa
Tensile strength	400	–	640	MPa
Specific strength	35.2	–	44.9	kN.m/kg
Elongation	20	–	40	% strain
Compressive strength	275	–	350	MPa
Flexural modulus	195	–	205	GPa
Flexural strength (modulus of rupture)	275	–	350	MPa
Shear modulus	75	–	81	GPa
Bulk modulus	144	–	159	GPa
Poisson’s ratio	0.275	–	0.285
Shape factor	59
Hardness – Vickers	190	–	225	HV
Hardness – Rockwell B	80	–	96	HRB
Hardness – Rockwell C	8	–	17	HRC
Hardness – Brinell	206	–	228	HB
Elastic stored energy (springs)	191	–	303	kJ/m3
Fatigue strength at 10^7 cycles	231	–	300	MPa
Fatigue strength model (stress range) Parameters: Stress Ratio = -1, Number of Cycles = 1e7cycles	169	–	411	MPa

AISI 444 Impact & fracture properties

Fracture toughness	62	–	119	MPa.m0.5
Toughness (G)	20.8	–	65.4	kJ/m2

AISI 444 Thermal properties

Melting point	1370	–	1480	°C
Maximum service temperature	693	–	758	°C
Minimum service temperature	-73	–	-43	°C
Thermal conductivity	25	–	29	W/m.°C
Specific heat capacity	400	–	440	J/kg.°C
Thermal expansion coefficient	9	–	11	µstrain/°C
Thermal shock resistance	134	–	182	°C
Thermal distortion resistance	2.39	–	3.06	MW/m
Latent heat of fusion	260	–	285	kJ/kg

AISI 444 Electrical properties

Electrical resistivity	57	–	67	µohm.cm
Electrical conductivity	2.57	–	3.02	%IACS
Galvanic potential	-0.16	–	-0.08	V

AISI 444 Magnetic properties

Magnetic type

Magnetic

AISI 444 Optical, aesthetic and acoustic properties

Transparency	Opaque
Acoustic velocity	4990	–	5140	m/s
Mechanical loss coefficient (tan delta)	9.1e-4	–	0.00125

AISI 444 Processing properties

Metal casting	Unsuitable
Metal cold forming	Limited use
Metal hot forming	Acceptable
Metal press forming	Limited use
Metal deep drawing	Limited use
Machining speed	24.7 m/min
Weldability Notes: Preheating and post weld heat treatment are not required	Poor
Weldability – MIG	Fair
Weldability – plasma	Fair
Weldability – SAW	Not recommended
Weldability – TIG	Fair
Brazeability	Fair
Carbon equivalency	0.7 – 0.925

AISI 444 Durability

Water (fresh)	Excellent
Water (salt)	Excellent
Weak acids	Excellent
Strong acids	Acceptable
Weak alkalis	Excellent
Strong alkalis	Limited use
Organic solvents	Excellent
Oxidation at 500C	Excellent
UV radiation (sunlight)	Excellent
Galling resistance (adhesive wear) Notes: Aluminum bronze is the most suitable mating material to minimize galling.	Limited use
Flammability	Non-flammable

AISI 444 Corrosion resistance

Pitting resistance equivalent number (PREN)	23.3 – 28.3
Pitting and crevice corrosion	Medium (20-30)
Stress corrosion cracking Note: Rated in chloride; Other susceptible environments: Hydrogen sulfide	Not susceptible
Intergranular (weld line) corrosion	Good
Inorganic acids	Restricted
Organic acids	Restricted
Alkalis	Moderate
Humidity / water	Excellent
Sea water	Good
Sour oil and gas	Restricted

AISI 444 Standards with similar compositions

Australia: 444 to AS 1449

Japan: SUS444 to JIS G4303

USA: S44400 to SAE J405, UNS S44400

Tradenames: J&L 444, UGINOX F 18 MT