The production of nodular cast iron piston ring of Liyan company is the same as that of NPR, that is, the nodular cast iron piston ring adopts the double piece casting process introduced from German gerz company, and the short cylinder nodular cast iron piston ring is also produced by Guangyang sm-50v boxless vertical parting molding line.
According to the Japanese personnel, the slicing of double nodular cast iron piston ring blank is relatively simple. The slicing machine has small volume, low manufacturing cost and high slicing efficiency, while the slicing machine requirements and manufacturing cost of cylinder nodular cast iron piston ring blank are much higher.
In actual production, the number of double piece rings is much more than that of barrel rings. Barrel casting process is only used in some varieties of mass production, which is not suitable for rings with too large or too small cylinder diameter.
In addition, from the piston ring samples brought back from Japan, Russia and other countries for domestic analysis, the metallographic structure of the cylinder nodular cast iron piston ring is not as good as that of the two-piece casting process, which is affected by the chemical composition or cooling rate, which needs to be further studied.