| 摘要 |
There is disclosed a method of and apparatus for producing a wear-resistant coating on a thin metallic strip, for example for the manufacture of coating scrapers for paper webs. After preparatory surface treatment the strip is passed longitudinally through a coating zone in which coating material in a molten state is sprayed onto the strip by a coating unit as the strip passes. The wear-resistant coating is built up in steps by the application of several coating layers one on top of the other, each being applied during a respective pass of the strip through the coating zone. The strip speed and the capacity of the coating unit are adjusted in relation to each other so that the heat supplied to the carrier material by each coating layer applied will be so slight in relation to the thermal capacity of the carrier material that the temperature increase in the carrier material does not cause any change in the physical properties of the carrier material. After each pass of the strip, the strip is caused or allowed to cool so that the heat applied to the carrier material by the spraying on of each layer of coating is substantially removed therefrom before a new coating layer is applied. In a preferred method the strip is fed from one reel, over a roller to pass the coating unit, to be taken up on another reel and the apparatus is reversed after each pass so that the strip passes back and forth through the coating zone for successive coating steps. |
