1. Classification of cold formed spring steel wire
1) Cold drawn steel wire: JISG3522 piano wire (SWP-A, SWP-B, SWP-C,)
JISG3521 high carbon steel wire (SWA, SWB, SWC,)
JISG4314 stainless steel wire for spring (sus302-WPA, WPB, sus304-WPA, WPB, sus316-WPA, su3631J1-WPC)
2) Heat-treated steel wire: JISG3560 carbon oil quenched steel wire for spring SWD-A, SWD-B
JISG3561 Carbon oil quenched steel wire for valve spring SWD-V
JISG3565 Ming vanadium oil quenched steel wire for valve spring SWDCV-V
JISG3566 Silicon Ming oil quenched steel wire for valve spring SWDSC-V
JISG3567 Silico-manganese oil quenched steel wire for spring SWDSM-A, SWDSM-B, SWDSM-C
JSMA.NO.11 Silicon Ming quenched steel wire for spring SWDSC
2. Piano wire and high carbon steel wire
Piano wire is a high-quality spring material produced from wire with low content of impurity elements (P, S, Cu) and surface defects such as hairline decarburization. This wire is usually used to produce precision springs. Compared with piano wire, high-carbon steel wire does not require strict fatigue strength and spring characteristics, but it is not far behind piano wire.
Three, oil quenched steel wire
There are SWP-V, SWO-V, SWOCV and SWOSC-V spring steel wires for the production of automotive valves. In recent years, with the increase in engine revolutions and higher operating temperatures, higher requirements have been placed on the fatigue resistance and fire resistance of hardened steel wires. Suspension springs are developing towards high stress and light weight. At present, the traditional materials 50CWA, SUP12, SuP7, SAE9259 are difficult to handle the stress above 1100Mpa, and tend to be eliminated. Their substitutes SAE9254TV, SRS60, UHS1900 and UHS2000 tend to be widely used.
Four, stainless steel wire for spring
Spring production also has strict requirements on stainless steel wire. In addition to the characteristics of stainless steel and corrosion resistance, it is now required that stainless steel wires should have higher tensile strength, and the fatigue life should be comparable to piano steel wires. Precipitation hardening stainless spring wire has a broader prospect. With the development of auxiliary materials for drawing, all this is gradually being realized.
5. Surface treatment steel wire
1) Variety of coated steel wires: In general, the spring is formed and then layered again, which will affect the performance of the spring. The use of steel wires produced by first plating and then drawing can reduce this to a certain extent.
2) Types of existing coatings: zinc plating, nickel plating, tin plating, copper plating, or mixed plating, etc.
Six, other spring steel wire
Maraging steel wire
In engine valve springs, when the engine revolutions exceed 10,000 times/hour under high stress, the material is required to have high heat resistance. But when the oil quenched steel wire fails to meet such requirements, the maraging steel wire can be used. The low temperature nitriding treatment is very effective in improving the characteristics of the valve spring.