Cast iron SCH20
Designation
| Name |
The value |
| Designation GOST Cyrillic |
СЧ20 |
| Designation GOST Latin |
CCh20 |
| Transliteration |
SCh20 |
| The chemical elements |
- |
Description
Cast iron SCH20 used: for the manufacture of castings with the lowest allowable wall thickness 10 mm: crankcases, covers, cylinder blocks, brake drums, heads and cylinder liners and other parts to automobile and tractor construction; machine beds, machine tools, surface plates, cylinders, valves, machine bases, rails, tables, in machine tools; exhaust pipes, flywheels, crankcases fundamental frames, covers, working cylinders, blocks, and other critical parts of the diesel engine; covers, gears, gears, gears, pulleys, flywheels (at a rate of not more than 3.5 m/s), frames, gearboxes, couplings, steam cylinders and other parts sredneshirotnykh chemical engineering; parts working in compression (Bashmakov, columns); various pipes and radiators; castings for stationary steam turbines, turbine equipment, nuclear power plants, elements of steam boilers and pipelines, hydraulic turbines, hydraulic locks, and other equipment engineering: casting 3 groups subjected to static loads and castings, working in conditions of water vapor and oil at temperatures up to 70 °C (Cabinet, bearing housings, caps-support volobouev, frames, bearings, frames, foundations, liners, bushings, racks, nozzles, covers); casts of group 2, operating at temperatures up to 250 °C, exposed to high static and dynamic loads and friction (pistons, housings, bearing housings, housings worm wheels, bushings, bearing caps, nozzles, compressors, diaphragms, frames, Foundation, frames, exhaust parts, compressor pipes, gear wheels, gear); casting parts of valves and actuators to it; casting parts mining and metallurgical equipment; cast connecting parts for pipelines.
Standards
| Name |
Code |
Standards |
| Castings with special properties (cast iron and steel) |
В83 |
KSt 81-033:2009 |
| Cast iron |
В11 |
GOST 1412-85, STP М319-95 |
| Pipes from ferrous metals and alloys cast and connecting parts to them |
В61 |
GOST 5525-88, GOST 9583-75 |
| Castings of cast iron (gray and malleable cast iron) |
В81 |
OST 108.962.01-85, OST 24.207.01-90, OST 23.4.258-86, OST 23.4.117-84, TU 14-3-964-80, TU 1-812-0072-94 |
Chemical composition
| Standard |
C |
S |
P |
Mn |
Cr |
Si |
Fe |
| GOST 1412-85 |
3.3-3.5 |
≤0.15 |
≤0.2 |
0.7-1 |
- |
1.4-2.4 |
The rest |
| KSt 81-033:2009 |
3.3-3.5 |
≤0.15 |
≤0.2 |
0.7-1 |
- |
1.4-2.4 |
The rest |
| STP М319-95 |
3.2-3.7 |
≤0.15 |
≤0.2 |
0.4-0.9 |
≤0.15 |
1.5-2.3 |
The rest |
Fe is the basis.
According to GOST 1412-85, low alloying of cast iron by various elements (chromium, nickel, copper, phosphorus, etc.) is allowed.
According to the STP M319-95 in cast iron, a chromium content of not more than 0.30% is allowed on medium and large non-castable castings with a wall thickness of 20 mm or more. Chill castings should be made of cast iron with an increased content of silicon, which should be 1.70-2.30%.
Mechanical characteristics
| Section, mm |
σB, MPa |
Brinell hardness number, MPa |
| Approximate data on the time resistance to tensile and hardness in the walls of castings according to GOST 1412-85, STP М319-95 |
| 15 |
≥200 |
≤230 |
| Castings in cast or heat treated condition for STP М319-95 |
| - |
≥200 |
170-241 |
| Approximate data on the time resistance to tensile and hardness in the walls of castings according to GOST 1412-85, STP М319-95 |
| 150 |
≥120 |
≤143 |
| Part of the connecting piping (sand casting) according to GOST 5525-88 (NV - in the center of a wall) |
| - |
≥150 |
≤250 |
| Approximate data on the time resistance to tensile and hardness in the walls of castings according to GOST 1412-85, STP М319-95 |
| 30 |
≥160 |
≤216 |
| 4 |
≥270 |
≤255 |
| 50 |
≥140 |
≤170 |
| 8 |
≥220 |
≤240 |
| 80 |
≥130 |
≤163 |
Description mechanical marks
| Name |
Description |
| Section |
Section |
| σB |
Limit short-term strength |
Physical characteristics
| Temperature |
Е, ГПа |
r, кг/м3 |
l, Вт/(м · °С) |
С, Дж/(кг · °С) |
| 20 |
85-110 |
7100 |
54 |
480 |
A description of the physical symbols
| Name |
Description |
| Е |
The normal elasticity modulus |
| l |
Coefficient of thermal conductivity |
Technological properties
| Name |
The value |
| Microstructure |
Pearlitic perlito-ferritic, ferrite-pearlitic. Graphite plate small, medium and large. |
