Alloy 455 is an alloy melted by several sources. Custom 455 is a trademarked name of Carpenter Specialty Alloys. It is a martensitic age-hardenable stainless steel that offers a unique set of qualities. This alloy is double vacuum-melted using a Vacuum Induction Melt (VIM) followed by a Vacuum Arc Remelt (VAR).
A reducing atmosphere is preferred for thermal treatment, but inert gas can be used. Alloy 455 will fully anneal at 950-980°C in just a few minutes. Alloy 455 can minimally age harden with a loss in ductility when held for prolonged periods at 370-540°C. Original hardness can be restored by heating at 590°C.
Alloy 455 has the advantage of allowing parts fabrication in the more easily worked as-delivered state, after which heat treatment can develop a much higher ultimate
tensile strength. Unlike many other heat treatable alloys, Alloy 455 has good oxidation resistance at room temperature. Primary end applications are needles, stylets, pins and springs.
Stainless steels develop a highly polished appearance as they are drawn to fine diameters. Surface roughness can be less than 5 microinches RMS when processed using single crystal natural diamond dies and measured with a profilometer. Diameters over 0.040" are finished with polycrystalline dies and exhibit a rougher surface than natural diamond dies. Diameters over 0.100" have an even rougher surface because they are drawn with carbide dies. Additional finish reatments can enhance the surface of the wire.