PURPOSE: To reduce cost of a wide clad product by superposing sheet metals to constitute clad material and heat resistant steel sheet metal as peeling material and winding up these sheet metals in a coil shape and then, subjecting the coil to vacuum annealing.
CONSTITUTION: Two or more kinds of sheet metals of materials such as Ni sheet metal and stainless steel sheet metal and the heat resistant steel sheet metal as the peel material are provided and the sheet metal as core material, the clad material and the heat resistant steel sheet metal are wound up in order. The formed coil is tightened by the last heat resistant sheet metal and then, the whole of the coil is charged in a vacuum furnace and heated up to the prescribed temperature and the clad sheet metals are joined together and cooled. By this method, the need for a large-sized rolling mill, etc., to join the dissimilar materials is eliminated and the sheet metals are clad by the vacuum annealing treatment. Accordingly, cost of the wide clad product is reduced.
TAKEDA SEIICHI
SASAKI MASAHIRO
YOKOYAMA KAZUHISA
