Cast iron SCH25
Designation
| Name |
The value |
| Designation GOST Cyrillic |
СЧ25 |
| Designation GOST Latin |
CCh25 |
| Transliteration |
SCh25 |
| The chemical elements |
- |
Description
Cast iron SCH25 is used: for the manufacture of various castings for critical applications with the lowest allowable wall thickness 15 mm: blocks and cylinder heads, liners, flywheels in automotive and tractor industry; machine beds, machine beds drill rigs, surface plates, cylinders, valves, machine tools, blocks, drums, wheels, bushings, couplings bearings and other thelongitudinal; piston heads, bushings, cylinder covers and other parts operating on the abrasion at elevated temperatures in diesel technology; critical parts working in compression (Bashmakov, columns); boilers for melting caustic soda, pipes, elbows and other parts in chemical engineering, working in solutions and melts of alkalies; casting 2 groups for stationary steam turbines, turbine equipment, nuclear power plants, elements of steam boilers and pipelines, hydraulic turbines, hydraulic valves and other equipment power plant engineering, 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, RAM Foundation, RAM exhaust parts, nozzles, compressors, gear wheels, gear); casting parts of valves and actuators to it; cast connecting parts for pipes; casting parts mining and metallurgical equipment.
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 1-812-0072-94 |
Chemical composition
| Standard |
C |
S |
P |
Mn |
Cr |
Si |
Fe |
| GOST 1412-85 |
3.2-3.4 |
≤0.15 |
≤0.2 |
0.7-1 |
- |
1.4-2.2 |
The rest |
| KSt 81-033:2009 |
3.2-3.4 |
≤0.15 |
≤0.2 |
0.7-1 |
- |
1.4-2.2 |
The rest |
| STP М319-95 |
3-3.4 |
≤0.15 |
≤0.2 |
0.7-1 |
≤0.25 |
1.5-2 |
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.
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 |
≥250 |
≤245 |
| Castings in cast or heat treated condition for STP М319-95 |
| - |
≥250 |
180-250 |
| Approximate data on the time resistance to tensile and hardness in the walls of castings according to GOST 1412-85, STP М319-95 |
| 150 |
≥150 |
≤156 |
| 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 |
≥210 |
≤238 |
| 4 |
≥310 |
≤260 |
| 50 |
≥180 |
≤187 |
| 8 |
≥270 |
≤255 |
| 80 |
≥165 |
≤170 |
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 |
90-110 |
7200 |
50 |
500 |
A description of the physical symbols
| Name |
Description |
| Е |
The normal elasticity modulus |
| l |
Coefficient of thermal conductivity |
Technological properties
| Name |
The value |
| Microstructure |
Perlite or pearlitic-ferritic. Graphite plate, small and medium. |
