Henning, H. J.
Metallurgist, The Ladish Co., Cudahy, Wis
Pages: 7 Published: Jan 1965
This paper describes the existing state-of-the-art for production forgings manufactured from steels treatable to strengths in excess of 200,000 psi. The need for increasing cleanliness with an increasing strength requirement is emphasized, particularly for those applications where design criteria require high transverse ductility. Economical vacuum arc melting has been largely responsible for bringing reliable, reproducible high-strength steel forgings to a production level of activity. Experience in forging a variety of alloys has highlighted relative levels of uniformity and reliability. Some of the more often selected high-strength steels are discussed from the standpoint of ease of forging, uniformity of strength response, and general quality. Data are given on cleanliness, transverse ductility, and other important properties for such alloys as Ladish D-6ac, AMS 6427, and AISI 4340. Methods for achieving high strengths vary from the standard quench and draw to the more complex thermal-mechanical treatments. The latter treatments, while readily applied to flat products, are difficult to impart to most forgings because complex shapes do not lend themselves to uniform levels of reduction. Mechanical property values obtainable in forgings produced from maraging steel are discussed. These steels represent a potential for the highest strengths obtainable in the steel family. The highest ductilities, however, are obtained by forging sequences that require added manufacturing steps. Since this represents added cost, data useful for specifying practical levels of properties are presented.
Paper ID: STP47120S