455

Melt Practice

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).

Typical Chemistry

	FWM Avg. Wt. %	AMS 5617G #1
Carbon	0.008	0.03
Manganese	0.05	0.5
Silicon	0.07	0.5
Phosphorus	0.006	0.015
Sulphur	0.003	0.015
Chromium	11.27	11.0-12.5
Nickel	8.22	7.5-9.5
Molybdenum	0.07	0.5
Copper	2.13	1.5-2.5
Titanium	1.14	0.9-1.4
Iron	Balance	Balance
Nitrogen	0.003	0.02

FWM chemistry is for reference only, and is not to be used for specification purposes.

Physical Properties

Density	0.280 lbs/in³
Modulus Of Elasticity	29.0 psi x 10⁶
Electrical Resistivity	758 µohms-mm
Thermal Conductivity	18.0 W/mK (100.25°C)

Thermal Treatment

A reducing atmosphere is preferred for thermal treatment, but inert gas can be used. Alloy 455 will fully anneal at 950-980.25°C in just a few minutes. Alloy 455 can minimally age harden with a loss in ductility, when held for prolonged periods at 370C-540.25°C. Original hardness can be restored by heating at 590.25°C.

Applications

Alloy 455 is a great material in that you can fabricate a part from material at a lower ultimate tensile strength and then heat treat it to a much higher 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.

Mechanical Properties

%CW	Y.S.(psi)	% Elongation (10" gauge length)
0%	145,000	6.3%
20%	153,000	5.7%
37%	161,000	3.8%
50%	165,000	3.5%
60%	173,000	4.6%
68%	185,000	2.4%
75%	190,000	2.5%
80%	193,000	2.6%
84%	199,000	2.6%
87%	210,000	2.2%
90%	220,000	2.5%
92%	230,000	2.4%

Values are typical and may not represent all diameters. Test method will affect results.

Surface Condition

Stainless steels develop a highly polished appearance as they are drawn to fine diameters. Surface roughness can be less than 5 RMS when processed using SCND* 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" will have an even rougher surface because they are drawn with carbide dies.

*SCND means single crystal natural diamond.

455