Development of wrought precipitation strengthened IN939 superalloy

Abstract

The potential of cast IN939 superalloy to be converted to wrought alloy has been explored in the present work. For this objective, bars of cast alloy were rolled under different conditions and then subjected to various heat treatment cycles. The results indicated that the yield strength, ultimate tensile strength and ductility of the wrought IN939 alloy are superior to the cast version. The stress rupture properties of wrought IN939 superalloy are better than those of the widely used superalloys, such as Nimonic 90 and Waspaloy, and approach the alloy Nimonic 105 properties. This is very notable because Nimonic 105 contains ∼45 vol.-% γ′ that is much greater than the volume fraction of those strengthening precipitates in the alloy IN939 (∼35%). On the whole, the wrought form of this alloy has a high potential for manufacturing hot components to be used safely under aggressive turbine environment.

Keywords:

• Nickel base superalloys
• IN939
• Cast
• Wrought
• Microstructure
• Mechanical properties