The Dimensional Reduction of Spheroidal Graphite Cast Iron Parts with Burr
Spheroidal graphite cast iron parts are widely used in mechanical engineering, which is a high-alloy material with good wear resistance, corrosion resistance, toughness and impact resistance. Its hardness and strength are higher than ordinary cast iron, and its strength is close to that of low alloy steel. In the production process of spheroidal graphite castings, burr defects often occur due to improper pouring or trimming. Burr often increases the overall size of the casting and affects product performance, so it is important to reduce the dimensional reduction of the casting with burr.
The burr of spheroidal graphite castings can be eliminated by grinding and polishing. During the grinding process, the contact area between the grinding wheel and the surface of the part needs to be increased to ensure that all burrs can be grinded away. When the burr is grinded away, the remaining surface needs to be ground until the surface is smooth. After grinding and polishing, it is necessary to re-measure the size of the part, compare the size before removing the burr, and check whether the burr removal is successful or not.
If the area of the part with burr is large, thermal treatment method can be used to reduce the dimensional reduction of the part with burr. The thermal treatment of spheroidal graphite cast iron parts with burr is to heat the part to a certain temperature, keep it at this temperature for a certain time, then cool the part to a proper temperature, shape it and then further process it. This method can change the mechanical properties of the spheroidal graphite castings, reduce the hardness and increase the plasticity. It can make the spheroidal graphite castings be cold worked and eventually achieve the target size.
Hot riveting and hot pressing method can also reduce the dimensional reduction of spheroidal graphite castings with burr. In the hot riveting process, rivets are first heated until they are red hot and then heated and pressed onto the casting. After cooling, the burr and excess metal will be pushed into the rivet hole, thus reducing the dimensional reduction of the Casting. In the hot pressing process, a suitable tool is heated until it is red hot and then pressed against the burr to deform it, thus reducing the dimensional reduction of the casting with burr.
In conclusion, by grinding, polishing, thermal treatment, hot riveting and hot pressing, the dimensional reduction of spheroidal graphite castings with burr can be effectively reduced, thus ensuring that the parts meet the requirements of product performance and quality.
