Ductile iron is an important material in strong and tough cast iron. Its strength, plasticity and toughness are higher than other cast iron, and it has good vibration absorption and wear resistance. Based on the above characteristics of materials, ductile iron is widely used in construction machinery, energy machinery, defense and military industry and other heavy and large load-bearing structural parts.
(1) By establishing the pouring position of the split face up, and carrying out detailed analysis from the core structure, pouring system, chill iron design and other aspects, a reasonable casting process plan is obtained, and the simulation analysis is carried out with the MAGMA software. The results show that the quality requirements of the ductile iron castings can be met.
(2) Combined with the process plan, the key quality points in the production process of ductile iron castings are controlled. After the actual production verification, the metallographic structure, mechanical properties, NDT inspection and other aspects can meet the technical requirements, and qualified ductile iron castings that meet the customer’s use requirements are obtained.
(3) For this kind of ductile cast iron thermal power low pressure inner cylinder products, the enterprise has developed and trial-produced several products successfully, and formed batch and serial production, which proves that this kind of products can completely use ductile cast iron casting instead of the original steel plate welding, and has the advantages of short cycle and low cost.
The discussed large thermal power low-pressure inner cylinder product is the successful application of ductile cast iron material in the core components of thermal power generation units. Its stress situation is relatively complex, and it has been in the working environment of high temperature and pressure for a long time. It has high requirements for the strength, toughness and wear resistance of the material. The low-pressure inner cylinder components of the original operating unit are welded and formed by steel plates. With the rapid development of ductile iron materials and its application technology, the effective substitution of ductile iron materials for carbon steel materials has been successfully realized. The casting integrated forming method has been adopted to avoid common weld quality and heat treatment deformation problems, so that the unit has achieved higher flow efficiency and lower energy consumption loss, and the product manufacturing cycle is shorter and the cost is lower, It has a good competitive advantage.