ABSTRACT
N. SRIDHAR and F. GALEN HODGE Haynes International, Inc. Kokomo, Indiana
INTRODUCTION
No class of alloys shows as wide a range of applications as the Ni-based alloys. These alloys are used as corrosion-resistant alloys, heating elements, controlled expansion alloys, creep-resistant alloys in turbines and jet engines, and high-temperature corrosion-resistant alloys. What makes this array of applications possible is not only the electrochemical properties of nickel but also its crystallographic characteristics that enable it to accommodate large amounts of alloying elements that, in turn, lend these alloys their unique properties. This chapter will be devoted to the alloys developed mainly for their corrosion resistance. These alloys are mainly solid-solutionstrengthened alloys supplied in the fully annealed condition. However, some precipitation hardenable Ni-based alloys will also be discussed where their corrosion properties are of importance. The purpose overall will be to present the strengths and weaknesses of these alloys and their areas of application. Discussion of corrosion mechanisms and physical metallurgy will be kept to a minimum. However, references, which elaborate the physical metallurgy and corrosion mechanisms, are cited under each alloy category.
