Patent ID: 8895106

Claim:
A batch process for coating an iron or steel article with a Zn—Fe intermetallic layer, comprising: providing a sealable furnace, comprising a process chamber equipped with a heating component, a component for introducing and extracting gasses, and access ports for the article to be coated; taking the article to be coated into the process chamber; contacting the article at a temperature of 200 to 650° C. with a reducing gas in the process chamber, thereby removing surface oxidation; extracting gasses from the process chamber to a residual pressure of less than 1000 Pa; contacting the article at a temperature of 225 to 650° C. with metallic Zn vapor in the process chamber, thereby coating the article with a Zn—Fe intermetallic layer; retrieving the coated article from the process chamber; wherein when contacting the article with metallic Zn vapor, the temperature of the article is equal to or higher than the dew point of the Zn vapor.