New Technology of Strengthening and Toughening Ductile Graphite Cast Pipe

Ductile iron pipes have excellent properties, such as good vibration absorption, good wear resistance, good corrosion resistance and so on. They have been widely used in industry. During the Osaka-Shenzhen earthquake in Japan, only ductile iron pipelines with flexible joints were basically intact. The pipelines of other materials were almost destroyed, showing excellent performance. However, nodular cast iron also has some common defects, such as low tensile strength, poor plastic deformation, and can not be processed under pressure.

The new technology of ductile iron strengthening and toughening studied in this project includes: (1) the tensile strength of ductile iron can reach 900 MPa and the elongation is 8-10%. It can greatly reduce the wall thickness and weight of castings, and can also make engine crankshaft, etc. (2) It can be processed under pressure, and the tensile strength of ductile iron can reach 1000 MPa after processing, and the elongation is 5-8%. The ball bearing made of ductile iron has good shock absorption and vibration reduction. Good wear resistance, hardness after quenching can reach HRC56-58. It can be applied in the field of mechanical manufacturing with a scale of about 200,000 yuan and investment.