Incoloy A-286

Alloy A286 is a precipitation hardening that combines high strength and good corrosion resistance, austenitic stainless steel designed for use at temperatures up to 1300°F (704°C) , where high tensile strength, excellent creep strength and good corrosion resistance are required. LSS™ A286 is available in a wide range of ingot, billet, bar, and coil rod sizes. Bar is available as either rounds or flats.

A286 alloy provides high strength up to a temperature of 1300° F and corrosion resistance up to a constant temperature of 1500° F or an intermittent temperature of 1800° F. A286, which is a ductile, non-magnetic, iron-based alloy, can reach its highest strength level through solution heat treating and age hardening. Because it is a higher strength metal, greater pressureis required when forming. It is best to weld and form A286 in the solution treated condition. Before machining A286, it is best to solution treat and cold working the material first.

A286 alloy is a heat and corrosion resistant austenitic ironbase material which can be age hardened to a high strength level. The alloy is also used for low temperature applications requiring a ductile, non-magnetic high strength material at temperatures ranging from above room temperature down to at least -320°F (-196°C). The alloy may be used for moderatecorrosion applications in aqueous solutions. Type A286 alloy can be produced by AOD refining or vacuum induction melting. Vacuum arc or electroslag remelting procedures may be used to further refine the material. Type A286 alloy is available in plate, sheet and strip.

A286 is an iron-nickel-chromium alloy with additions of molybdenum and titanium. A 286 is one of the most popular high temperature alloys. As one of the austenitic alloys it maintains good strength and oxidation resistance at temperatures up to 1300ºF. Due to it’s high strength and excellent fabrication characteristics A286 is used in various components of aircraft and industrial gas turbines. A286 is also widely used in the offshore oil and gas industry where the components are subject to high levels of heat and stress.

Alloy A286 Chemical Composition

Incoloy A286 Specifications:

AMS 5731 AMS 5732 AMS 5734 AMS 5737 AMS 5895 ASTM A638 Elliott Turbine MS618 EN10204 DIN3.1B. AISI 660 AISI 662 AMS 5525 AMS 5726 AMS 5731 AMS 5732 AMS 5734 AMS 5737 AMS 5804 AMS 5805 AMS 5853 AMS 5858 AMS 5895 ASTM A453 Grade 660 ASTM A638 Grade 660 DIN 1.4943 DIN 1.4944 GE B50T1181 GE B50T12 GE B50T81 SPS M250 UNS S66286

Alloy A286 Corrosion Resistance

The following table is for reference only, many factors can affect the corrosive resistance, a corrosion test for each application should be applied.

Alloy A286 Typical Room Temperature Mechanical properties

Solution treated 1800f (982c) for one hour and oil quenched, aged 1325f (719c) 16 hours and air cooled.

Alloy A286 Physical properties:

A286 Solution Treated and Aged (1800ºF)

A286 Solution Treated and Aged is covered by specifications AMS 5732, BS HR51, ASTM A638 660 Type 2, ASTM A453 660 Class B

A286 Solution Treated and Aged (1650ºF)

A286 Solution Treated and Aged is covered by specifications AMS 5737, ASTM A638 660 Type 1, ASTM A453 660 Class A and EN-2303 (under 4″ Bar)

A286 Other

AMS 5853 – 15% cold reduced (160 ksi/ 1103 Mpa tensile strength)

AMS 5726 – 40-50% cold reduced (200 ksi/ 1379 Mpa tensile strength)

Machinability: A-286 will machine easier than other high temperature metals, such as 718. Using carbide inserts will help. Readily machined by standard methods. Similar in behavior to the machining of the austenitic stainless steel. Cemented carbide tools are best for high cutting rates as in turning operations. Turning: Surface speed of 300-325 fpm using carbide tooling at feed rate of 0.008 inches per revolution. Use water base coolant or lubricant. Drilling: High speed steel drills with a positive rake work well. Feed rates are 0.001″ to 0.006″ per revolution, with the smaller feed rate the smaller the hole diameter being drilled. Surface speed range 25-35 feet per minute. Milling: Rigid machines and fixtures are essential for a good milled finish. Cutting speeds of 30-40 surface feet per minute with a feed rate of 0.003″ to 0.005″ per mill cutter tooth should be used. Grinding behavior is very similar to that of steel. Wet grinding is best using aluminum oxide grinding wheels.

Welding: As with all nickel containing alloy cleanliness of the area to be welded is of paramount importance. Welding procedures and processes are the same as used for stainless steel. Preheating or post welding heat treatment is not required. Welds should always have a raised (convex) weld bead and matching filler metal should be used. The alloy should be in the solution annealed condition for optimum welding results. It is susceptible to hot cracking and that tendency is aggravated in the aged condition.

Heat Treatment: The alloy is solution annealed at 1800 F and oil quenched, followed by holding at 1325 F for 16 hours and air cool. This treatment develops high strength for the alloy.

Hardening: As with austenitic stainless steel hardening of this alloy is accomplished by cold working. However the alloy, as is common with many of the iron-nickel alloys containing titanium, may be age hardened. Refer to “Aging” listing.