In China, you could find many types of cast iron fire grates, such as round fire grate, square fire grate, camping fire grate etc.
According to the application, the cast iron fire grates could be divided into gas fire grate, coal fire grate and wood stove fire grate.
The material of fire grate is usually grey iron, or called as gray iron. Normally, it is not necessary to produce the fire grate by nodular iron (ductile iron), since grey cast iron is cheaper. Some clients may require to add some Cr (chrome), Ni and Mo alloys to improve its anti-fire property. According to the experience of Dandong Foundry in China, the Cr is useful for the high temperature fire grate, but Ni and Mo are not necessary, but it will depends on the different applications.
As for the casting process for fire grates, for small grates, we suggest to use the green sand floor molding process, which is the most cheap and suitable for the fire grates, since this process can keep the liquid hot iron into the sand molds for one night, which could keep the good flatness for the fire grates.
For the large fire grates, which are very seldom, you could consider to use the resin sand casting process.
For the large quantity fire grates, such as over 30 thousands of pieces each year, you could try to use the automatic molding line because of its high production rate. However, not all grates could be produced by automatic molding lines since the short time cooling and drastic vibration cleaning may could the deformation to the fire grates.
As a buyer for the cast iron fire grate, what are the main issues for your purchasing process in China?
Firstly, of course, find a good iron foundry who has the experience in producing fire grates and can offer a reasonable price.
Secondly, checking the material to the sample and batch products. In order to reduce the material costs, some small foundries may use the large quantity of scarp iron as the main material, therefore, their grates could not meet the material requirements, mainly means the tensile strength requirement. Unqualified material will cause the fire grates very fragile.
Thirdly, check the dimensions, especially the flatness, and the surface quality. Since most of cast iron fire grates are anti-rust painted, therefore, the repairing by the cast iron repairing adhesive or welding, should be allowable. However, if the clients need further porcelain enamel coating treatment. Then, any types of repairing will be forbidden since the repairing may affect the failure of the porcelain treatment.
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