After QT800-2, QT900-2 and other brands of nodular cast iron crankshafts were produced, Guangxi Yuchai and others have been able to stably produce QT800-6 crankshafts after tackling key problems, laying a foundation for "replacing steel with iron" for crankshafts.
1. smelting
Obtaining high temperature and low sulfur pure molten iron is the key to produce high quality nodular cast iron. Domestic production equipment is mainly cupola, and molten iron has not been pre-desulphurized. Secondly, there is less high purity pig iron and poor coke quality.
At present, the melting method of duplex plus pre-desulfurization has been adopted. The molten iron is melted in cupola, desulfurized outside the furnace, and then heated in induction furnace and adjusted in composition. At present, the vacuum direct reading spectrometer has been widely used to detect the composition of molten iron in China.
2. Modeling
The air impact molding process is obviously superior to the clay sand molding process, and can obtain high-precision crankshaft castings. The sand mold produced by this process has the characteristics of no rebound deformation, which is especially important for multi-throw crankshafts.
At present, some domestic crankshaft manufacturers have introduced air impact molding technology from Germany, Italy, Spain and other countries. However, only a few manufacturers have introduced the entire production line, such as Wendeng Tianrun Crankshaft Co., Ltd. which has introduced German KW casting production line.
Xingchang Fan Company can produce all kinds of precision machined parts, especially crankshaft and pulley products.
Contact us to learn more: Cast iron Bushing.