DIN 17222 71Si7 1.5029 Cold Rolled Steel Strips for Springs

Cold rolled steel strip for springs is distinguished by high dimensional accuracy and good surface quality and, in the cold rolled + hardened + tempered condition (H + A) offers the possibility of achieving high values of hardness, tensile strength and elastic limit.

71Si7 1.5029 Introduce

71Si7 1.5029 steel is an unalloyed medium carbon engineering steel which has 0.68%-0.75% Carbon and 1.5%-1.8% Silicon. It will obtain high hardness and high strength after hardening due to the relatively high carbon content.

71Si7 1.5029 Dimensions and permissible deviations

Thickness: 0.1 to 4mm; Tolerances: +/- 0.008 to 0.11 mm

Width: 10 to 600mm; Tolerances: +/- 0.15 to 0.60mm

71Si7 1.5029 Chemical composition

71Si7 1.5029 Treatment condition on delivery

Cold rolled + soft annealed : G

Cold rolled + hardened + tempered : H + A

71Si7 1.5029 Mechanical properties in the cold rolled + soft annealed condition G

71Si7 1.5029 Tensile strength in the cold rolled + hardened + tempered condition (H + A)

71Si7 1.5029 Vickers hardness in the cold rolled + hardened + tempered condition (H + A)

71Si7 1.5029 Surface condition

Strip to be supplied in the

1 cold rolled + soft annealed G or

2 cold rolled + soft annealed + cold rolled (G + K) condition

must have a bright, metallically clean surface.

Cold rolled + hardened + tempered (H + A) strip is supplied, as agreed at the time of ordering, with

1 grey-blue (GR),

2 bright (8K),

3 polished (P) or

4 polished and colour-tempered (P & AF) surface.

71Si7 1.5029 Types of heat treatment

Approximate values for heat treatment and minimum hardness values in the hardened condition of cold rolled steel strips for springs

71Si7 1.5029 Acceptance testing and test certificates

EN 10204/3.1 with all relevant data reg. chem. composition, mech. properties and results of testing.