Iron-base-superalloy, Cr-Ni alloy, A-286, solution treated & aged

(High-Alloy Steel)

A 286 Designation

A-286
Condition: Solution treated & aged
UNS number	S66286
US name	AMS 5528, AMS 5726, AMS 5731, AMS 5732, AMS 5734, AMS 5737, AMS 5804, AMS 5805, ASTM A453 660
EN name	BS HR 650, 286S31
EN number	1.4944, 1.4943
JIS (Japanese) name	JIS G4311 SUH660

A 286 Typical uses

Aerospace components, turbine parts, petrochemical processing equipment, heat-treating systems, motor and transformer core laminations, toroids, magnetic shielding, electrical relays, and communications equipment.

A 286 Composition detail

Al (aluminum)	0	–	0.35	%
B (boron)	0.001	–	0.01	%
C (carbon)	0	–	0.08	%
Cr (chromium)	13.5	–	16	%
Fe (iron)	49.1	–	59.5	%
Mn (manganese)	0	–	2	%
Mo (molybdenum)	1	–	1.5	%
Ni (nickel)	24	–	27	%
P (phosphorus)	0	–	0.04	%
S (sulfur)	0	–	0.03	%
Si (silicon)	0	–	1	%
Ti (titanium)	1.9	–	2.35	%
V (vanadium)	0.1	–	0.5	%

A 286 Physical properties

Density

7.9

–

7.98

g/cm³

A 286 Mechanical properties

Young’s modulus	201	–	211	GPa
Specific stiffness	25.3	–	26.6	MN.m/kg
Yield strength (elastic limit)	586	–	655	MPa
Tensile strength	896	–	990	MPa
Specific strength	73.8	–	82.5	kN.m/kg
Elongation	12	–	15	% strain
Compressive strength	586	–	779	MPa
Flexural modulus	201	–	211	GPa
Flexural strength (modulus of rupture)	586	–	655	MPa
Shear modulus	77	–	80.9	GPa
Bulk modulus	176	–	185	GPa
Poisson’s ratio	0.31	–	0.323
Shape factor	39
Hardness – Vickers	287	–	330	HV
Hardness – Rockwell C	32	–	35	HRC
Elastic stored energy (springs)	834	–	1040	kJ/m³
Fatigue strength at 10^7 cycles	358	–	434	MPa
Fatigue strength model (stress range) Parameters: Stress Ratio = -1, Number of Cycles = 1e7cycles	344	–	451	MPa

A 286 Impact & fracture properties

Fracture toughness	132	–	150	MPa.m^0.5
Toughness (G)	84.7	–	109	kJ/m²

A 286 Thermal properties

Melting point	1370	–	1400	°C
Maximum service temperature	632	–	705	°C
Minimum service temperature	-73	–	-53	°C
Thermal conductivity	12.5	–	13.5	W/m.°C
Specific heat capacity	461	–	480	J/kg.°C
Thermal expansion coefficient	16.6	–	17.4	µstrain/°C
Thermal shock resistance	166	–	189	°C
Thermal distortion resistance	0.731	–	0.803	MW/m
Latent heat of fusion	222	–	310	kJ/kg

A 286 Electrical properties

Electrical resistivity	91	–	93	µohm.cm
Electrical conductivity	1.85	–	1.89	%IACS
Galvanic potential	-0.19	–	-0.11	V

A 286 Magnetic properties

Magnetic type

Non-magnetic

A 286 Optical, aesthetic and acoustic properties

Transparency	Opaque
Acoustic velocity	5030	–	5160	m/s
Mechanical loss coefficient (tan delta)	2e-4	–	5e-4

A 286 Processing properties

Metal casting	Limited use
Metal cold forming	Excellent
Metal hot forming	Excellent
Metal press forming	Acceptable
Metal deep drawing	Limited use
Machining speed	7.92 m/min
Weldability _{Notes: Preheating and post weld heat treatments may be required}	Poor
Carbon equivalency	0.932 – 1.36

A 286 Durability

Water (fresh)	Excellent
Water (salt)	Excellent
Weak acids	Excellent
Strong acids	Acceptable
Weak alkalis	Excellent
Strong alkalis	Excellent
Organic solvents	Excellent
Oxidation at 500C	Excellent
UV radiation (sunlight)	Excellent
Galling resistance (adhesive wear) _{Notes: Bronze or zinc alloy dies should be used to minimize galling.}	Limited use
Flammability	Non-flammable

A 286 Corrosion resistance

Pitting resistance equivalent number (PREN)	16.8 – 21
Pitting and crevice corrosion	Low (<20)
Stress corrosion cracking Note: Rated in chloride; May be susceptible in halide, ammonia, nitrogen, acidic, caustic, carbonate environments	Slightly susceptible

A 286 Other notes

The best known Ni/Fe Alloy is “INVAR” which has a thermal expansion coefficient that is close to zero at room temperature.

A 286 Standards with similar compositions

South Korea: STH 660-WSA to KS D 3697

USA: 660 Class D to ASTM A453/A453M, 660 to ASTM A453/A453M

Tradenames: AMANOX 3980, ARMCO A-286, EMVAC 286, INCO A-286, JESSOP-SAVILLE G 68, KRUPP WL 1.4943, KRUPP WL 1.4944, LESCALLOY A-286, UDIMET A-286, WITTEN DA 1525 LVA, WITTEN S 1525 LVA