Cast iron SCH21

Designation

Name The value
Designation GOST Cyrillic СЧ21
Designation GOST Latin CCh21
Transliteration SCh21
By chemical elements -

Description

Cast iron SCH21 used: for the manufacture of castings of heads and cylinder blocks in car and tractor construction; machine beds, marking plates, cylinders, valves, machine tools; exhaust pipes, flywheels, fundamental frames, crankcases, covers, working cylinders, blocks, and other critical parts in diesel technology; gears, pulleys, and other machines are significantly loaded items in chemical engineering; casting parts of valves and actuators to it; cast connecting parts for pipelines.

Note

Ferritic-pearlitic cast iron.

Standards

Name Code Standards
Cast iron В11 GOST 1412-85
Pipes of ferrous metals and alloys, cast fittings to them В61 GOST 5525-88, GOST 9583-75
Cast iron castings (grey and malleable cast iron) В81 OST 24.207.01-90

Chemical composition

Standard C S P Mn Cr Si Ni Fe
GOST 1412-85 2.8-3.4 ≤0.12 ≤0.4 0.5-1.5 ≤0.4 1.3-2.4 ≤0.5 Rest
Fe is the basis.
The chemical composition is given on the basis of GOST 1412-54 data and reference literature based on obtaining the required time resistance at break and calculating the carbon equivalent, in GOST 1412-85 the chemical composition is not specified, while it is allowed to make castings from cast iron grade СЧ21 at the request of the consumer. Allowed low alloying of cast iron with various elements (chromium, nickel, copper, phosphorus, etc.).

Mechanical properties

σU, MPa HB, MPa
Castings in cast or heat treated condition for STP М319-95
≥210 -
Part of the connecting piping (sand casting) according to GOST 5525-88 (NV - in the center of a wall)
≥150 ≤250

Description mechanical marks

Name Description
σU Limit short-term strength
HB Brinell hardness number