摘要 |
The present invention provides conveying rolls and hearth rolls in a continuous annealing furnace for producing steel sheet having flame sprayed coatings on their surfaces wherein the flame sprayed coatings are comprised of cermet having a ceramic ingredient content of 80 vol % or less or a heat resistant alloy, the flame sprayed coatings have oxide layers comprised of one or more of a flame sprayed metal, Cr, Si, Zr, or Al, and a ratio R/R1 of the roughness parameter R of the surface of the oxide layer measured based on JIS B0633 setting the cutoff value at an initial value and a roughness parameter R′ measured setting the cutoff value at 1/10 of the initial value is 4 or more. |