Casting Technology of Nodular Cast Iron Crankshaft Blank

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 producing 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 a cupola, desulfurized outside the furnace, and then heated in an 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 similar 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 the German KW casting production line.

Xingchang Fan Company can produce all kinds of precision machined parts, especially crankshaft and pulley products.