| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a cold-rolled steel sheet having a superior mold galling property even when used as a hard-to-mold material such as a steel sheet of high strength in which the surface pressure is increased during press molding. <P>SOLUTION: An inorganic coating that has an average thickness of 10 to 2,000 nm and contains a crystalline layered substance is formed on a surface layer of a steel sheet. The crystalline layered substance is preferably, for example, a layered double hydroxide represented by [M<SP POS="POST">2+</SP><SB POS="POST">1-X</SB>M<SP POS="POST">3+</SP><SB POS="POST">X</SB>(OH)<SB POS="POST">2</SB>][A<SP POS="POST">n-</SP>]<SB POS="POST">x/n</SB>.zH<SB POS="POST">2</SB>O, where M<SP POS="POST">2+</SP>represents one or two or more kinds of Mg<SP POS="POST">2+</SP>, Ca<SP POS="POST">2+</SP>, Fe<SP POS="POST">2+</SP>, Ni<SP POS="POST">2+</SP>, and Zn<SP POS="POST">2+</SP>; M<SP POS="POST">3+</SP>represents one or two or more kinds of Al<SP POS="POST">3+</SP>, Fe<SP POS="POST">3+</SP>, and Cr<SP POS="POST">3+</SP>; and A<SP POS="POST">n-</SP>represents one or two or more kinds of OH<SP POS="POST">-</SP>, CO<SB POS="POST">3</SB><SP POS="POST">2-</SP>, Cl<SP POS="POST">-</SP>, and (SO<SB POS="POST">4</SB>)<SP POS="POST">2-</SP>. <P>COPYRIGHT: (C)2012,JPO&INPIT |
