PURPOSE: To improve the seizure-and-peel-resistant properties of a guide shoe and to extend its service life by using a guide shoe, for manufacturing a seamless pipe, having the surface provided with an undercut part on which ceramics are overlayed by spraying.
CONSTITUTION: A guide shoe 1 for manufacturing a seamless pipe is made of special high carbon Ni-Cr-Mo steel, etc. and; a part, liable to wear by the contact with a high temperature seamless pipe, is undercut at undercut angles θ1, θ2, θ3, θ4 respectively, and a metal excellent in oxydation-resistant properties, such as Ni-Cr alloy or Cr, is sprayed, as a substrate material, on the undercut part 3, which is heat treated at 900W1,300°C for 30minW1hr to diffuse the metal in the undercut part 3 and to adhere it tightly to the part 3. Next, ceramic powder of ZnO2, Al2O3, TiO2, Cr2O3, SiO2, MgO, Si3N4, etc. is sprayed independently or after compounding them to overlay it on the part 3, then the part 3 is prevented from being worn by the friction between it and the seamless pipe.
HIRAI MASAO
KAMATA AKIO