On-Line Measurement System of Degree of Alloying for Galvannealed Steel Sheet

摘要

Galvannealed steel sheet is mainly used for the electronic panel and the body of a vehicle because it has good properties in welding, painting, press forming, and corrosiveness(1). All of these properties are strongly affected by the degree of alloying of zinc-coated layer on the steel sheet. In this sense, the control of the alloying is very important at teh continuous galvanizing line. The degree of alloying of a zinc-coated layer is defined as the amount of iron that is diffused into zinc layer. This parameter is determined by the heat treatment of steel strip after dipping into a zinc-pot.