angle-left

Web Content Display

Email a friend

Ultrahigh-Strength Steels

Author: Revised by Thoni V. Philip, TVP Inc.; and Thomas J. McCaffrey, Carpenter Steel Division of Carpenter Technology Corporation   |   Document Download   |   Product code: ZASMHBA0001027

File size: 1 MB

Classified as: Carbon and Alloy Steels

Price: $30.00 Member Price: $24.00

IN STOCK Information about shipping / delivery

Description Delivery Options Classifications
STRUCTURAL STEELS with very high strength levels are often referred to as ultrahigh-strength steels. The designation ultrahigh-strength is arbitrary because no universally accepted strength level for the term has been established. Also, as structural steels with greater and greater strength have been developed, the strength range for which the term is applied has gradually increased. This article describes those commercial structural steels capable of a minimum yield strength of 1380 MPa (200 ksi). In addition to the steels discussed in this article, many other proprietary and standard steels are used for essentially the same types of applications, but at strength levels slightly below the arbitrary, lower limit of 1380 MPa (200 ksi) established above for the ultrahigh-strength class of constructional steels. Medium-alloy steels such as 4330V and 4335V (vanadium-modified versions of the corresponding AISI standard steels) are among the more widely used steels for yield strengths of 1240 to 1380 MPa (180 to 200 ksi). Certain proprietary steels such as Hy Tuf (a silicon-modified steel similar to 300M) exhibit excellent toughness at strengths up to or slightly above 1380 MPa. The toughness of Hy Tuf is about the same as a maraging steel in this strength range. For properties and other information on steels and strength ranges not discussed here, the reader is referred to sources such as Aerospace Structural Metals Handbook (Ref) and to producer data sheets. The ultrahigh-strength class of constructional steels is quite broad and includes several distinctly different families of steels. This article covers only medium-carbon low-alloy steels, medium-alloy air-hardening steels, and high fracture toughness steels. It does not cover 18Ni maraging steels, which are described in the article "Maraging Steels" in this Volume. Ultrahigh-strength steels of the stainless type (martensitic, martensitic precipitation hardenable, semiaustenitic precipitation hardenable, and cold-rolled austenitic steels) are covered in the Section "Specialty Steels and Heat-Resistant Alloys" in this Volume. The effects of thermomechanical treatments such as ausforming and hot-cold working on the properties of many ultrahigh-strength steels have been investigated extensively. With adequate deformation while the steel is in a metastable condition, strength levels not attainable by standard quench and temper treatments have been obtained, quite often with higher ductility and fracture toughness than those normally expected at these very high strength levels. However, such thermomechanical treatments are not widely used commercially, presumably because of practical difficulties in adapting experimental techniques to actual production. Therefore, thermomechanical treatments and the properties that result from them are also excluded from this article.
  • From: ASM Handbook Volume 1, Properties and Selection: Irons, Steels, and High-Performance Alloys (ASM International)
  • Published: 1990
  • Pages: 19
  • Review Type: Peer reviewed