MIL-C-24723

Abstract

This specification covers three nickel-copper alloys for static or centrifugal casting for corrosion resistant service. <br>Nickel-copper alloy castings shall be of the following compositions, as specified (see <a>6.2</a>): </span><pre> Composition M-30C (see <a>6.1.1</a>) M-30H (see <a>6.1.2</a>) M-25S (see <a>6.1.3</a>)</pre> <br> <br><b><u>Intended Use:</u></b> Nickel-copper alloy composition M-30C is a weldable alloy intended for use in parts requiring moderate strength, high ductility and high resistance to corrosion. Nickel-copper-silicon alloy, composition M-30H is intended for applications involving nongalling and antiseizing characteristics coupled with moderately high hardness, high strength and relative ease of machinability. Weldability is poor. Nickel-copper-silicon alloy, composition M-25S is intended for use where nongalling and antiseizing characteristics combined with high hardness, and good corrosion and abrasion resistance are desired. Weldability is poor. Nickel-copper-silicon alloy, composition M-25S, while machinable in the as-cast condition, is capable of being solution treated for improved machinability and, subsequently, age hardened to a minimum Brinell hardness of 300 and finish machined or ground. However, caution should be exercised in the quenching procedure to avoid the possibility of thermal cracking; pilot heat treatment of parts is recommended before attempting heat treatment. If cooling is fast enough from the pouring temperature to keep all alloys in solution, the castings may be directly aged without solution treating. Heat treatment procedure is described in the supplements to ASTM A 494. <br>