Cast iron SCH25

Designation

Name The value
Designation GOST Cyrillic СЧ25
Designation GOST Latin CCh25
Transliteration SCh25
By 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 (iron and steel) В83 KSt 81-033:2009
Cast iron В11 GOST 1412-85, STP М319-95
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 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 Rest
KSt 81-033:2009 3.2-3.4 ≤0.15 ≤0.2 0.7-1 - 1.4-2.2 Rest
STP М319-95 3-3.4 ≤0.15 ≤0.2 0.7-1 ≤0.25 1.5-2 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 properties

Section, mm σU, MPa HB, 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
σU Limit short-term strength
HB Brinell hardness number

Physical characteristics

Temperature Е, HPa r, kg/m3 l, W/(m · °C) С, J/(kg · °C)
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.