Water cooled rolls for cooling steel sheets

摘要

A water-cooled roll for cooling steel sheets is spray-coated on the surface that comes in contact with the steel sheets with a cermet composed of a metal oxide having a higher hardness and lower thermal conductivity than metals and a metal matrix of Ni- or Co-base heat-resisting alloy. The metal oxide is chosen from among Al2O3, Cr2O3, SiO2, and ZrO2, and the metal matrix consists of an MCrAlY (M=Co or Ni). Preferably, the metal oxide is alumina and the metal matrix, CoCrAlYTa.