Ductile iron casting

To judge the quality of ductile iron, you can start from the following aspects:
1. Spheroidization rate: high spheroidization rate, uniform distribution of graphite balls, good sphericity, can improve the strength, toughness and wear resistance of castings. In general, nodular cast iron with a spheroidization rate of more than 80% is considered to be of better quality.
2. Mechanical properties: High strength, good toughness and impact resistance are important characteristics of high-quality ductile iron to ensure that it can withstand high loads and high stresses.
3. Microstructure: The internal structure of ductile iron should be based on ferrite and pearlite, and try to reduce or avoid impurities such as carbide and phosphorus eutectic, which will reduce the mechanical properties of the casting and make it brittle.
4. Surface quality: The surface should have no obvious defects, such as pores, sand holes, cracks, cold insulation, sand and so on. High precision and good surface quality are very important for subsequent machining and assembly.
5.Residual stress: Heat treatment such as annealing is usually required to reduce the stress and ensure the stability of the casting during use.
The quality of nodular cast iron is judged comprehensively by checking the nodular rate, mechanical properties, microstructure, dimensional accuracy, surface quality, etc.
Product composition is strictly controlled, there is an independent physical and chemical laboratory, each batch of raw materials are strictly tested, carburizer low sulfur, low nitrogen, low phosphorus.
The material of the casting is strictly controlled by experienced melting engineers, using wood mold resin sand molding process, adding copper alloy process, the casting has high rigidity, strong tensile resistance, deflection resistance and other high-quality characteristics.