| 摘要 |
PURPOSE:To provide corrosion resistance, abrasion resistance, etc. to a steel pipe by melting the local part of the inside circumferential surface of the steel pipe by a laser and meltsticking an amorphous alloy thereby forming amorphous alloy layers successively in the longitudinal direction of the steel pipe. CONSTITUTION:The laser from a laser head 10 is changed of direction with a mirror 1, and is focused at the inside circumferential surface of a steel pipe 1 with a lens 12, thereby melting the local surface thereof. On the other hand, an inert gas is fed through a supply pipe 13 to suck the amorphous alloy powder in a hopper 14 and to eject the same through a nozzle 15, thereby spraying the powder on the inside circumferential surface of the pipe 1 melted by the laser. Since the pipe 1 and a revolving shaft 5 revolve at a high speed in opposite directions, the molten part moves quickly. The locally molten parts are moved relatively in an axial direction at every prescribed pitch at every one relative rotation by a feeder 9 and therefore the quickly cooled structure, that is, amorphous alloy layers are formed successively in part or the whole of the length of the inside circumferential surface of the steel pipe 1. |
