Abstract: An improved layout of the hearth rolls in an annealing furnace comprises a plurality of ceramic coated rolls and a plated rolls. The ceramic coated rolls are arranged in a region in the annealing furnace, where the temperature is higher than 450.degree. C. On the other hand, the plated rolls are arranged in a region where the temperature is lower than or equal to 450.degree. C. The hearth roll is provided a wear resistant coating of chrome plate or sprayed on ceramic of a thickness greater than or equal to 1 .mu.m and less than or equal to 100 .mu.m. In addition, according to the invention, the hearth roll is provided a surface roughness Ra in the range of 4.5 .mu.m to 20 .mu.m.

Abstract: A process for preventing transverse displacement of metal strip comprises correcting a shape of metal strip into flat form prior to the travel of the metal strip into a continuous annealing furnace when continuously annealing the metal strip in the furnace under a condition of LSD.gtoreq.100 (representing a product of line speed and strip gauge).

Abstract: An apparatus for plating a metal strip in an electrolytic cell is provided with a supporting roll. The support roll is disposed apart from the deflector rolls by a predetermined distance and supports the metal strip in such a way that the catenary of the metal strip can be reduced. The distance is determined so that the catenary is 0.04 or less times of the distance between upper and lower electrodes in the electrolytic cell. When the metal strip is a steel plate having a density of 7.85.times.10.sup.-6 (kg/mm.sup.3), the predetermined distance l (mm) between the axis of the deflector roll and that of the supporting roll is subject to the following formula: ##EQU1## in which the distance between the upper and lower electrodes is .DELTA.D (mm), the thickness of the metal strip being t (mm), the width thereof being W (mm) and the tension applied to the metal strip being T (kg).

Abstract: One-side zinc hot dipped steel sheets are produced by coating one surface of a steel sheet with an aqueous slurry of an anti-plating agent based on MgO, alkali metal silicates, boric acid, MOH (M is an alkali metal) and the like and containing such additives as TiO.sub.2 and Al.sub.2 O.sub.3, heating the coated sheet for drying and baking, immersing the steel sheet with an anti-plating film in a molten zinc bath to zinc plate the other surface of the sheet, wetting the anti-plating film, and bending the steel sheet to cause the anti-plating film to peel off, thereby removing the anti-plating film from the steel sheet. This invention carries out the coating and baking of the anti-plating agent such that it is baked to a film having a thickness of 20 to 60 microns at a temperature of 750.degree. C. to about 930.degree. C.