Ductile iron crankshaft blank casting technology
(1) Smelting
The acquisition of high-temperature, low-sulfur, pure molten iron is the key to producing high-quality ductile iron. The domestic production equipment is mainly based on cupola, and the molten iron is not pre-desulfurized; the second is high-purity pig iron and poor coke quality. At present, a double-external pre-desulfurization smelting method has been adopted, which uses a cupola to melt molten iron, desulfurizes it outside the furnace, and then heats up and adjusts the composition in an induction furnace. At present, the detection of domestic molten iron components has been generally carried out using a vacuum direct reading spectrometer.
 
(2) Modeling
The airflow impact molding process is obviously superior to the clay sand type process, and high-precision crankshaft castings can be obtained. The sand mold produced by the process has the characteristics of no rebound deformation, which is especially important for the multi-turn crankshaft. At present, some crankshaft manufacturers in China have introduced airflow impact molding processes from Germany, Italy, Spain and other countries. However, only a few manufacturers have introduced the entire production line. For example, Wendeng Tianrun Crankshaft Co., Ltd. has introduced the German KW casting production line.