A286 Steel

┃ Material

UNS S66286, SAE HEV7, 1.4944, 1.4980, X5NiCrTi26-15, Incoloy^® alloy A-286, GH2132

Note that the designation “Incoloy^® Alloy A-286” is registered trademark of the Special Metals Corporation group of companies.

┃ Overview

Alloy A-286 (Fe-25Ni-15Cr) is an iron based austenitic precipitation reinforced iron-nickel-chromium high temperature alloy, which is integrated strengthening with molybdenum, titanium, aluminum, vanadium and trace boron. It has high yield strength and persistent and creep strength under 650℃, and it has good machining plasticity and satisfactory welding performance. Also Alloy A-286 is known for its good strength and oxidation resistance especially at temperatures up to 1300°F (704°C).

Alloy A-286 has high yield strength, persistent and creep strength under 650℃, and it has good machining plasticity and satisfactory welding performance.

┃ Characteristics

◇ Good machinability

◇ Excellent fabrication characteristics

◇ Good oxidation resistance up to 800°C

◇ Can be produced by AOD reefing or vacuum induction melting

◇ Good creep-rupture strength during extended high-temperature exposure

◇ Non-magnetic even after severe cold deformation

◇ High ductility in notched sections

◇ Very high corrosion resistance

◇ Good for moderate corrosion applications in aqueous solutions

◇ High mechanical properties due to age-hardenability

◇ Good creep-rupture strength during extended high-temperature exposure

◇ High strengths that are well retained up to 700°C

┃ Application

Alloy A-286 is widely used in the manufacture of components on aeroengines and industrial gas turbines,  and also widely used in automobile engines, also used as high-temperature bearing parts of aeroengines, which are under 650℃ for long-term operation.

Alloy A-286 is also very popular in offshore oil and gas industry where high levels of heat and stress are a factor.

┃ Chemical composition (wt% as per AMS 5731)

Material	C	Si	Mn	P	S	Cr	Ni	Mo
S66286	≤0.08	≤1.0	≤2.0	≤0.025	≤0.025	13.5~16.0	24.0~27.0	1.0~1.5
A-286	0.03~0.08	≤0.5	1.0~2.0	≤0.020	≤0.015	13.5~16.0	24.0~27.0	1.0~1.5
Material	Ti	B	V	Co	Al	Cu	Pb
S66286	1.90~2.35	0.003~0.010	0.10~0.50	≤1.0	≤0.35	≤0.50
A-286	1.90~2.30	0.003~0.010	0.10~0.50	≤1.0	≤0.35	≤0.50	≤0.005

┃ Mechanical property

Tensile strength ksi (MPa)	Yield strength at 0.2 offset ksi (MPa)	Elongation in 2” % min.	Reduction of area % min.
130 (896)	85 (586)	15	20

┃ Corrosion resistance

Alloy A-286 has corrosion resistance similar to austenitic stainless steels in many environments. It has superior corrosion resistance to nickel-base alloys when exposed to sulfur contaminated atmospheres at elevated temperatures.The corrosion resistance of this alloy is excellent up to 1300 °F(704 °C) against many atmospheres encountered in jet engine service. Up to 1800°F (982°C), the oxidation resistance of alloy A-286 is equivalent to that of 310 Stainless Steel.

┃ Oxidation resistance

Alloy A-286 has excellent oxidation resistance up to 1800°F (982°C). High temperature sustainability and high tensile strength is the key factor for superior Oxidation resistance property of Alloy A286.

┃ Heat treatment

Solution heat treatment

Heat to 1800 ± 25°F (982± 14°C), hold 1 hour at heat, then cool rapidly in oil, water, or other means.

Precipitation Heat Treatment as per AMS 5732

Heat to a temperature within the range 1300 to 1400 °F (704 to 760 °C), hold at temperature for a total of not less than 16 hours, and cool at a rate equivalent to cooling in air.

┃ Available Process

(1) Hot formed, solution annealed, descaled

(2) Cold worked and bright annealed

(3) Cold worked, annealed and descaled

(4) Cold worked, polished (MP, EP etc.)

(5) Cold worked, bright annealed, polished (MP, EP etc.)

┃ Common Tests

Chemical composition

Tension

Hardness

Flaring

Flange

Flattening

Micro structure

Hydrostatic

NDT

Intergranular Corrosion

Surface condition

Shape and dimension

Positive Material Identification