Mono Block Research Articles

Analysis of Reforming Process of Large Distorted Ring in Final Enlarging Forging.

In the construction of reactors or pressure vessels for oil chemical plants and nuclear power stations, mono block open-die forging rings are often utilized. Generally, a large forged ring is manufactured by means of enlarging forging with reductions of the wall thickness. During the enlarging process the circular ring is often distorted and becomes an ellipse in shape. However the shape control of the ring is a complicated work. This phenomenon makes the matter still worse in forging of larger rings. In order to make precision forging of large rings, we have developed the forging method using a v-shape anvil. The v-shape anvil is geometrically adjusted to fit the distorted ring in the final circle and reform automatically the shape of the ring during enlarging forging. This paper has analyzed the reforming process of distorted ring by computer program based on F.E.M. and examined the effect on the precision of ring forging.

HIP法による二層シリンダライナの開発

Increasing demand for higher output and better fuel efficiency forces maximum combustion pressure of the engine higher and higher, requesting the same or even more reliability to the engine.At present mono block castiron cylinder liners are widely used for marine slow speed diesel engines simply because of their tribological superior characteristics.This paper introduces a solution of double layer cylinder liner by HIP (Hot Isostatic Pressing) method. This liner consists of two different materials. Inside material is tribologicaly superior material, in this case castiron. On the other hand outside material is strong material. Inside and outside material are fixed together using HIP method. The successful test results using test engine and production engine were also explained here.