，最好是原创
Spherical gray cast iron is a kind of gray cast iron with high strength, high elasticity and good toughness. It is mainly cast of high quality raw iron. Spherical gray cast iron is mainly used in manufacturing all kinds of bearing, gears and other mechanical transmission parts, etc.
The chemical composition of spherical gray cast iron should meet the requirements of GB/T1412-1985 Spherical Cast Iron of Raw Iron. The advantages of spherical cast iron of raw iron include: 1) high strength, compared to other cast iron, the spherical cast iron of raw iron has a higher strength level; 2) high elasticity, the spherical cast iron of raw iron can bear high dynamic loads and has better fatigue resistance; 3) good wear resistance, the surface hardness of the spherical cast iron of raw iron can reach HRC50-54, which makes it have better wear resistance than other cast iron.
The mechanical properties of spherical cast iron of raw iron should meet the requirements of GB/T1412-1985 Spherical Cast Iron of Raw Iron. The tensile strength of the cast iron should be no less than 240MPa, the impact toughness of the cast iron should be no less than 40J/cm, the hardness of the cast iron should be no less than HRC50, the surface roughness of the cast iron should be Ra3.2, and the porosity of the cast iron should be no more than 3.0 mm.
The physical properties of spherical gray cast iron should meet the requirements of GB/T1412-1985 Spherical Cast Iron of Raw Iron. The relative density of the cast iron should be 7.0 to 7.3. The thermal conductivity of cast iron should be no less than 48.36W/(m.K). The coefficient of thermal expansion of cast iron should be no more than 11.5 x 10-6/K. The high temperature strength of cast iron should be no less than 310MPa at 500℃.
The specific production process of spherical cast iron of raw iron should meet the requirements of GB/T1412-1985 Spherical Cast Iron of Raw Iron. The production process includes: heat up the raw iron to the required temperature; add some carbon, silicon, manganese and other alloy elements to the molten iron in order to obtain the required chemical composition; use the centrifugal casting machine to cast the molten iron into the spherical shape; quenching and tempering the cast iron, in order to improve the strength, toughness and wear resistance of the cast iron.
In conclusion, the raw iron of spherical cast iron can provide high strength, high elasticity and good wear resistance. It is usually used to manufacture all kinds of bearing, gears and other mechanical transmission parts. GB/T1412-1985 Spherical Cast Iron of Raw Iron provides the requirements of its chemical composition, mechanical properties, physical properties and production process.
