Alloy Steel Materials

Alloy steels contain deliberate additions of chromium, nickel, molybdenum, manganese, vanadium, or silicon beyond plain carbon steel levels—typically 1–5% total alloy content—to enhance hardenability, strength, toughness, and wear resistance. The AISI/SAE four-digit designation system (e.g., 4140, 4340, 8620) encodes the primary alloying elements: 41xx = Cr-Mo, 43xx = Ni-Cr-Mo, 86xx = Ni-Cr-Mo carburizing. Proper heat treatment is essential to achieve specified properties; the continuous cooling transformation (CCT) diagram governs the hardening response.

24 materials cross-referenced. Showing page 1 of 2.