Overview

Haynes 230 alloy is a nickel-chromium-tungsten-molybdenum alloy that combines excellent high-temperature strength, outstanding resistance to oxidizing environments up to 2100°F (1149°C) for prolonged exposures, premier resistance to nitriding environments, and excellent long-term thermal stability. It is readily fabricated and formed, and is castable. Other attractive features include lower thermal expansion characteristics than most high-temperature alloys, and a pronounced resistance to grain coarsening with prolonged exposure to high temperatures.

Limiting Chemical Composition, %

Nickel..............................................................................................................................................Balance

Carbon............................................................................................................................................0.05-0.15

Copper............................................................................................................................................20.0-24.0

Tungsten.....................................................................................................................................13.00-15.00

Cobalt.............................................................................................................................................5.00 max.

Molybdenum.......................................................................................................................................1.0-3.0

Aluminium.......................................................................................................................................0.20-0.50

Titanium..........................................................................................................................................0.10 max.

Iron...................................................................................................................................................3.00 max.

Lanthanum....................................................................................................................................0.005-0.05

Boron.............................................................................................................................................0.015 max.

Silicon..............................................................................................................................................0.25-0.75

Manganese......................................................................................................................................0.30-1.00

Sulphur...........................................................................................................................................0.015 max.

Copper..............................................................................................................................................0.50 max.

Phosphorus.....................................................................................................................................0.03 max.

Physical Constants

Mechanical Properties

The mechanical properties of Haynes 230 alloy are excellent. It has a yield strength at a room temperature of 210 MPa and an ultimate tensile strength at a room temperature of 500 MPa. It also has good ductility with a strain hardening exponent of 0.15 and an elongation at a break of 20%.

Corrosion Resistance

Haynes 230 alloy is highly resistant to corrosion in both acidic and alkaline environments, making it ideal for harsh environments where other alloys may not be suitable. It also has good oxidation resistance at elevated temperatures up to 1200°C, which makes it suitable for use in high-temperature applications such as aircraft turbine engines or industrial furnaces where other alloys may not be able to handle the heat load without deteriorating quickly.

Thermal Treatments：

Haynes 230 is a cobalt-based superalloy, and in order to optimize its properties, the following heat treatment steps are usually required:

Solution treatment: Haynes 230 is heated to 1150°C (2102°F) and held for 2 hours to ensure that the alloying elements are fully dissolved in the matrix.

Rapid cooling: After the solution treatment is completed, the material should be immediately air-cooled or water-cooled to room temperature to prevent alloying elements from precipitation during the cooling process.

Aging: Haynes 230 is heated to 870°C (1600°F) for 16 hours, then cooled to 760°C (1400°F) with the furnace, and finally air-cooled to room temperature. This step aims to precipitate alloying elements in the matrix and enhance the properties of the material.