Inconel A286 Material Overview And Advantages And Disadvantages Analysis

Inconel A286 is a high-performance nickel-based alloy known for its outstanding strength, corrosion resistance, and mechanical properties at elevated temperatures. Here is a detailed introduction to Inconel A286 alloy:

Alloy A286 Overview

A286 is a precipitation-hardened iron-nickel-chromium alloy and one of the most popular high-temperature alloys. It maintains good strength and oxidation resistance at temperatures up to 1300°F (about 700°C). A286 is widely used to manufacture various components for aircraft and industrial gas turbines, favored for its high strength and excellent processing properties. In addition, A286 is also very popular in the offshore oil and gas industry due to the high levels of heat and stress.

Material Properties

• Work Hardening: A286 has a work hardening level comparable to 310S stainless steel and can be cold worked at the same level.

• Corrosion Resistance: A286 has excellent corrosion resistance that exceeds standard 304 and 304L stainless steels, and this property does not change after the aging process.

• Machinability: Although A286 is more difficult to machine than 316 and 310 stainless steels, positive results can still be obtained through cold working. A286 is easier to machine than other high-temperature alloys.

Chemical composition

The chemical composition of Inconel A286 mainly includes the following elements and their maximum percentage content:

• Iron (Fe): maximum 54%

• Nickel (Ni): maximum 25.5%

• Chromium (Cr): maximum 14.8%

• Titanium (Ti): maximum 2.13%

• Molybdenum (Mo): maximum 1.30%

• Manganese (Mn): maximum 1.0%

• Silicon (Si): maximum 0.50%

• Vanadium (V): maximum 0.30%

• Aluminum (Al): maximum 0.18%

• Carbon (C): maximum 0.040%

• Phosphorus (P): maximum 0.020%

• Sulfur (S): maximum 0.015%

• Boron (B): maximum 0.0060%

The combination of these elements gives Inconel A286 excellent high temperature performance and corrosion resistance.

Heat Treatment

• Solution Treatment: A286 solution treated in accordance with AMS 5731 (also in accordance with AMS 5732).

• Solution Heat Treatment: 1800°F (about 982°C) ±25°F for 1 hour followed by water/oil quenching (in accordance with AMS).

• Hardness: ≥ 217HB or 220 HB (BS), ≥201HB (AMS).

• Solution Treatment and Aging (1800°F): A286 after solution treatment and aging meets AMS 5732, BS HR51, ASTM A638 660 Type 2, ASTM A453 660 Class B, etc.

• Solution heat treatment: 980°C ± 10°C for more than 1 hour followed by air cooling (in accordance with BS standards) or 1800°F ± 25°F for 1 hour followed by water/oil quenching (in accordance with AMS standards).

• Precipitation heat treatment: 720°C ± 10°C for more than 16 hours followed by air cooling (in accordance with BS standards) or 1300-1400°F (approximately 704-760°C) for not less than 16 hours followed by air cooling (in accordance with AMS standards).

• Hardness: 248 - 341 HB or 260 - 360 HV (BS standards), 248-341 HB (AMS standards).

Performance characteristics

1.High strength: Exhibits excellent mechanical properties at high temperatures, such as improved high temperature strength.

2.Corrosion resistance: Provides enhanced oxidation and corrosion resistance to surfaces exposed under different conditions.

3.Heat Treatability: Can be heat treated to increase consistent mechanical properties consistent with its special application.

4.Wide Temperature Range: Easy to process, its mechanical properties remain satisfactory over a wide temperature range.

Specifications and Standards

• Unified Numbering System (UNS): S66286

• Japanese Industrial Standard (JIS): G4312

• European Standard (EN): 1.4980, 10204 3.1

• American Petroleum Institute (API): PSL 3

• Nondestructive Testing Association (NACE): MR0-175

• Other standards and specifications include AMS 5525, AMS 5726, AMS 5731, AMS 5732 (formerly AMS 5735), AMS 5734, AMS 5737, AMS 5804, AMS 5853, AMS 5895, etc.

Advantages and Disadvantages

Advantages:

• Provides very good mechanical properties at high temperatures.

• The surface has enhanced resistance to oxidation and corrosion.

• Its properties can be improved by heat treatment.

Disadvantages:

• Higher cost, generally more expensive than many other stainless steels and nickel alloys on the market.

• Limited weldability, requiring specialized skills to avoid cracks.

• Heat treatment is sensitive and requires precise control to obtain the desired properties.

Size and form selection may be limited compared to some common alloys.

Applications

• Engine components such as turbine wheels, blades, frames, casings, afterburner components, high temperature fasteners and springs.

• Non-magnetic cryogenic equipment.

• Aircraft gas turbines.

• Offshore oil and gas industry.

• Cryogenic applications.

• Disks, blades and shafts for gas turbines.

• Compressors.

• Fasteners.

• Springs.

• Superchargers.

• Manifold components.

• Moderate corrosion applications in aqueous solutions.

• Non-magnetic cryogenic equipment.

These properties of Alloy A286 make it an ideal choice for applications under extreme temperature and stress conditions.