MATSUDOHONPURAINANOSEIZOHOHO

摘要

PURPOSE:To improve the reliability of a mud pump liner while decreasing the man- hour for working and to prevent the decrease in the wear resistance thereof by forming an inside cylinder by centrifugal casting of a wear resistant metal and heating the cylinder then installing the cylinder into a casting mold which is an outside cylinder and casting a tough metallic material into the mold at the point of the time when a limited temp. is attained to insert-cast the inside cylinder thereby forming an integral composite cylinder. CONSTITUTION:The inside cylinder 1 is made of a high-chromium cast iron by centrifugal casting. The outside surface of the inside cylinder is then roughly finished or is as cast and shot-blasted. After the cylinder 1 is heated to 700-900 deg.C, the cylinder is installed in the casting mold 10 which is the outside cylinder. The melt of a carbon steel or low alloy steel is poured into the spacing between the outside surface of the inside cylinder and the inside surface of the casting mold at the point of the time when the cylinde4 1 is at 400-600 deg.C to cast the cylinder 2. The casting consisting of the cylinder 1 embedded by casting in the cylinder 2 is taken out of the mold 10. The runner is removed and the inside surface of the cylinder 1, the outside surface of the cylinder 2 and both end faces are finished to prescribed sizes. The casting is subjected to a heat treatment if necessary.