Abstract: A system for descaling a strip of metal includes a nozzle assembly mounted within a spray box for spraying descaling product on the strip. The nozzle assembly includes a spray chamber; nozzles mounted directly to the spray chamber; and a heater for heating the chamber, the descaling product in the chamber, and the nozzles by conduction through the chamber. The nozzles are oriented to direct the descaling product in a spray against the upper and lower surfaces of the metal strip for an amount and a time sufficient to descale the metal strip. The nozzle assembly is attached to the spray box and can be easily removed therefrom for inspection.

Abstract: An improved salt and method of using such salt for conditioning scale on strip or sheet metal surfaces is provided. In more particular aspects, the invention provides an improved salt of alkali metal hydroxides and alkali metal nitrates which are used in their fused anhydrous form to condition scale on metal strip or sheet. The salt preferably contains from about 40% to about 70% potassium hydroxide, from about 20% to about 55% sodium hydroxide, and from about 2% to about 30% of an alkali metal nitrate. The salt is especially adapted to be sprayed onto a moving strip or sheet of metal as it passes a spray station, although it can also be used in conventional salt bath applications in which the salt is maintained in a fused condition in a tank, and the sheet, strip, bar, tubing or other form to be treated is immersed in the fused salt bath.

Abstract: A system for descaling a strip of metal includes a nozzle assembly mounted within a spray box for spraying descaling product on the strip. The nozzle assembly includes a spray chamber; nozzles mounted directly to the spray chamber; and a heater for heating the chamber, the descaling product in the chamber, and the nozzles by conduction through the chamber. The nozzles are oriented to direct the descaling product in a spray against the upper and lower surfaces of the metal strip for an amount and a time sufficient to descale the metal strip. The nozzle assembly is attached to the spray box and can be easily removed therefrom for inspection.

Abstract: A system for descaling a strip of metal includes a nozzle assembly mounted within a spray box for spraying descaling product on the strip. The nozzle assembly includes a spray chamber; nozzles mounted directly to the spray chamber; and a heater for heating the chamber, the descaling product in the chamber, and the nozzles by conduction through the chamber. The nozzles are oriented to direct the descaling product in a spray against the upper and lower surfaces of the metal strip for an amount and a time sufficient to descale the metal strip. The nozzle assembly is attached to the spray box and can be easily removed therefrom for inspection.

Abstract: A method and composition for stopping-off nitrogen and/or carbon diffusion into metal surfaces. The composition, which is a mixture of a refractory material selected from the group of zirconium and aluminosilicate, sodium silicofluoride and sodium silicate, is coated onto the metal surface where diffusion is to be prevented. The mixture is cured and the metal part is subjected to elevated temperatures for carburizing, nitriding, or carbonitriding. The coating prevents nitrogen and/or carbon diffusion at the coated area. After treatment the coating is removed.

Abstract: A method and composition for stopping-off nitrogen and/or carbon diffusion into metal surfaces. The composition, which is a mixture of a refractory material selected from the group of zirconium and aluminosilicate, sodium silicofluoride and sodium silicate, is coated onto the metal surface where diffusion is to be prevented. The mixture is cured and the metal part is subjected to elevated temperatures for carburizing, nitriding, or carbonitriding. The coating prevents nitrogen and/or carbon diffusion at the coated area. After treatment the coating is removed.