Cast iron bushing 40-400 mm SCH20

Cast iron bushing 40-400 mm SCH20 is an alloy of iron with carbon, in which graphite is present in the form of flaky, lamellar or fibrous inclusions.

A separate type (group of grades) of gray cast iron is ductile cast iron with globular graphite, which is achieved by modifying it with magnesium (Mg), cerium (Ce) or other elements.

Gray cast iron is marked with the letters SCH, after which the guaranteed value of the tensile strength in kg / mm² is indicated, for example, SCh20. Ductile irons are marked with the letters VCh, after which the strength is indicated and, through a dash, relative elongation in%, for example, VCh60-2.

Gray cast iron is characterized by high casting properties (low crystallization temperature, fluidity in the liquid state, low shrinkage) and serves as the main casting material. It is widely used in mechanical engineering for casting machine and mechanism frames, pistons, and cylinders.

The main method for the manufacture of cast iron bushings is casting into molds based on cold-hardening mixtures (CTS). Thanks to it, high quality bushings are achieved with minimal machining allowances and without gas defects and blockages in the workpiece. In our factory, the minimum diameter is 30mm, and the maximum diameter is 1000mm, the wall thickness is preferably not less than 1 centimeter, the length is not more than 1 meter.

Casting in XTS is a method of manufacturing bushings using various sand, artificial resin is used as a binder. To harden the tooling, blowing with gas catalysts - amines (organic compounds that are derivatives of ammonia, in the molecule of which one, two or three hydrogen atoms are replaced by hydrocarbon radicals) is used. The exact dosage of the amine evaporated in the heating device and the purge of the sleeve with a cast-iron vapor-gas mixture (amine vapor in the carrier gas) under a pressure of 0.03 - 0.30 MPa is carried out using a pneumatic evaporation apparatus. Then the bushing is blown with dried air in order to remove the spent amine by supplying the latter to the neutralizer. The chemical reaction of the amine increases with an increase in its concentration in the gas mixture (amine + inert carrier). When dry air is used as a carrier (moisture in any form is contraindicated in this process), the amine concentrate is limited to 1.5-2% to suppress accidental explosion. The shape of the sleeve is made of wood. Special software controls robotic machines that allow you to make pattern equipment from wood of any configuration. Model equipment is manufactured in accordance with GOST 3212-92.

For the operation of bushings in friction units, anti-friction cast iron is used with the following operating modes:

Careful assembly that ensures precise mating of the mating surfaces and the absence of distortion.

Continuous lubrication that does not allow sparks or significant heating of the friction unit.

The increase in clearances compared to those established for bronze by 15 - 30%, in the presence of significant heating of the friction unit in operation - up to 50%.

Run-in at idle and gradual increase in workloads.

of the main qualities can be noted:

     excellent vibration absorption,

     wear resistance,

     antifriction,

     crack resistance,

     heat resistance,

     good impact strength.

With all the advantages of cast iron bushings, the brittleness of cast iron compared to steels should be taken into account; products made of gray cast iron should not be used in impact mechanisms.

Scope of cast iron bushings

Cast iron bushings are used for mounting or dismounting pulleys, couplings, sprockets. The main advantage of cast iron bushings is low cost and ease of processing. Cast iron bushings are used for the manufacture of durable and wear-resistant parts: pistons, cylinders, engine blocks. For example, cast iron bushings SCH20 and SCH25 are used for parts that are operated under severe loads, simpler bushings are relevant for the manufacture of less loaded parts.

Classification of cast iron bushings

Cast iron bushings are classified according to the method of production, shape and purpose.

According to the shape, bushings are divided into smooth bushings, bushings with a smooth hole and a stepped outer surface, bushings with a smooth outer surface and a stepped hole, and bushings with a stepped hole and outer surface.

According to the production method, cast and stamped cast iron bushings are distinguished. In the manufacture of cast iron bushings, centrifugal casting is used, followed by annealing. Annealed cast iron bushings are a hot commodity of the Ural Foundry and Metallurgical Plant. Recently, experts have noted a high demand for cast iron bushings SCH20 and SCH25. Such cast iron bushings can be bought inexpensively due to the low energy intensity of production.

  You can buy the Pig-iron bushing 40-400 mm SCH20 from us at the most favorable price in Ukraine. A wide range of products allows us to quickly and efficiently fulfill any order, helping to complete any construction work on time.