Cause of Edge Peeling Around the Nozzle Bore of an SN Plate and Its Prevention

摘要

A peculiar peeling happened around the nozzle bore of a sliding nozzle plate (hereafter called SN plate). The cause was investigated through analysis by the Finite Element Method (hereafter called FEM). The design of an SN plate with a rounded bore edge~(1)) was developed to prevent the edge peeling.The results obtained from the FEM analysis indicate that lower thermal expansion coefficient and modulus of elasticity lowers the tensile shearing force generated in a material around a bore. As a result this reduces the probability of edge peeling. Materials for SN plates have high strength and corrosion resistance. However, they also commonly have a high thermal expansion coefficient and modulus of elasticity and therefore also have a tendency to suffer the peculiar edge peeling. The SN plate with a rounded bore edge designed from the results of this FEM analysis suggests the possibility to enlarge the application range of those materials with a high strength and corrosion resistance.