Spring steel

Spring steel is a steel having a higher strength as compared with other steels. There are many applications of spring steel, such as the springs in suspensions of motor vehicles are made from spring steel, but also the small spring, which compresses the pegs. Even modern battle-ready battle ready swords are made of spring steel.

Each component can be deformed up to a certain voltage by the material ( elastic limit ) to then return elastically to the original state without permanent deformation. The material property that enables this is the elasticity. In addition, continuous deformations lead to plastic deformation.

For example, the spring steel has a yield strength 38Si7 of at least 1150 N / mm ² ( at a tensile strength of 1300-1600 N / mm ²), as compared with 235 N / mm ² in the structural steel S235JR (tensile strength 360 N / mm ²). The key difference here is the yield ratio, ie the ratio of yield strength to tensile strength of the material, which is typically > 85% is in the range of spring steel.

Production

The elasticity of a spring steel excellent property is achieved by preparing an alloy with the corresponding properties. An alloying element, which favors this is (among others) silicon. It is also important to achieve a uniform distribution of the carbon content.

For a component made ​​of steel, which is resiliently loaded, it is important that the hardness of the material is distributed in a proper way through the cross section.

Industrial processes aim to achieve a uniform distribution of the alloying elements directly in the archetype process.

Examples of spring steels

Standardize

Below is a selection of ( retracted ) standards on the subject of spring steel and substitutes.

  • DIN 1570 Hot rolled ribbed steel spring; Weights, dimensions, tolerances, static values ​​; 1.2004 replaced by DIN EN 10092-2
  • DIN 4620 spring steel, hot-rolled, with rounded narrow sides of leaf springs; 1.2004 replaced by DIN EN 10092-1
  • DIN 17221 Hot rolled steels for quenched and tempered springs; 4.2003 replaces by DIN EN 10089
  • DIN 17222 Cold-rolled steel strip for springs; 5.2000 replaced by DIN EN 10132-1 and DIN EN 10132-4
  • DIN 17223-1 Round spring steel wire - Patented cold drawn spring wire made ​​of unalloyed steels; 12.2001 replaced by DIN EN 10270-1
  • DIN 17223-2 Round spring steel wire - Oil hardened and tempered spring steel wire of non-alloy and alloy steels; 12.2001 replaced by DIN EN 10270-2
  • DIN 17224 spring wire and spring strip of stainless steels; 2.2003 replaces by DIN EN 10151 and DIN EN 10270-3
  • DIN 59145 Spring steel, hot-rolled, semi-circular narrow sides; 1.2004 replaced by DIN EN 10092-1
  • DIN 59146 Spring steel, hot-rolled, with a rectangular cross section and rounded edges for leaf springs; 1.2004 replaced by DIN EN 10092-1
  • EURO NORM 89 Alloy steels for quenched and tempered springs thermoformed; Quality specifications; 12.2002 replaced by DIN EN 10089
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