When selecting wire for mechanical applications there are four classifications from which to choose a specific material or alloy. The four classifications are nickel based lockwires, carbon steels, stainless steels and superalloys. A three-part evaluation procedure is recommended:
- Initial screening based on temperature and corrosion requirements
- Analysis of physical properties; and
- Final screening on the basis of specific properties, material, and forming costs
|Alloy#||Inconel* 600||Inconel* X-750||Monel 400||Music Spring|
|Carbon ( C ) max.||.15||.08||.3||1|
|Manganese ( Mn ) max.||1||1.2||2||.6|
|Silicon ( Si ) max.||.5||.5||.5||.3|
|Phosphorus ( P ) max.||--||--||--||--|
|Sulfur ( S ) max.||.015||.01||.024||.03|
|Chromium ( Cr )||14 - 17||14 - 17||--||--|
|Nickel ( Ni )||72 min.||70 min.||63 - 70||--|
|Iron ( Fe )||6 - 10||5 - 9||2.5 max.||Balance|
|Others||( Cu ).5 max.||( Cu ) .5 max.|
( Al ) .4 -1
( Ti ) 2.25 - 2.75
( Cb ) .7 - 1.2
|( Cu ) Balance||--|
|Nominal Tensile Strength (kpsi)|
(size range: .002"-.032")
|Inconel* 600||Inconel* X-750||Monel 400||Music Spring|
|Annealed||90 - 130||130 - 160||70 - 95||None Listed|
|Full Hard (Spring)||180 - 230||220 - 250||145 - 180||330 - 480|
Characteristics of Mechanical Alloys
Inconel* 600: Resists corrosion and oxidation to 2150°F. Provides springs with high resistance to corrosion and heat up to 750°F. Tough and ductile down to -310°F; is nonmagnetic, easily fabricated and welded. Used for structural parts, cathode ray tube spiders, thyratron grids, sheathing, tube supports, spark plug electrodes.
Inconel* X-750: Age hardenable, nonmagnetic, corrosion and oxidation resistant; high creep-rupture strength 10 1300°F. Heavy cold working develops tensile strengths of 290,000 psi. Stays tough and ductile to -423°F. Resists chloride-ion stress-corrosion cracking. For springs operating to 1200°F and tube structural parts.
Monel 400: This material is noted for its toughness over a considerable range of temperatures, and has excellent resistance to many corrosive environments. Monel 400 can be hardened only by cold-working. It is useful at temperatures up to 1050°F, and has very good mechanical properties at temperatures below zero. Melting point is 2370 – 2460°F.
Music Spring: Music spring wire is high carbon steel of uniform chemical analysis. This wire is drawn within rigid tensile, smoothness, and roundness requirements and although very high in tensile strength, must be capable of wrapping around itself without showing signs of cracking or unevenness.