Through the introduction of formulating standard and the use of external iron chill in cast steel, the paper pointed out a way for saving cost, simplifying working processes and improving quality.

Extermal cooling technology is one of the key technology to realize fast-cast-rolling pro cess of a-lu mini um,that is through compulsive cooling on the outside surface of rollers to improve the cooling abili-ty of system during cast-rolling,so the interface heat transfer coefficient is the important factor for the ex ternal cooling tech nology under varied external cooling conditions.