STAINLESS STEEL HAVING EXCELLENT ADHESION PROPERTY OF SURFACE FILM AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain a stainless steel sheet improved in the adhesion property of various kinds of films mainly formed by ceramic thermal spraying by etching the steel sheet with an aq. ferric chloride soln. of a specific concn. and specifying the surface roughness thereof and the relative sectional area in the specific depth position of a relative load curve by its sectional curve. ;SOLUTION: The surface roughness Ra of this stainless steel is 1.6 to 2.4μ, the Rmax is ≤20μ and the relative sectional area (Tp₅₀) in the depth 50% position of the relative load curve by its sectional curve is ≤70%. This surface condition is obtd. by subjecting the steel sheet to spray etching by using the aq. ferric chloride soln. kept at 33 to 37°Be' (Baume degree). As the surface roughness Ra is generally higher, the adhesion property of the films improves but ≥1.6μ is necessary in order for obtaining the effect of improving the adhesion property by the shape of the relative load curve. If, on the other hand, the aq. ferric chloride soln. is excessively higher, the film thickness partially exceedingly decreases and, therefore, the surface roughness is confined to ≤2.4μ and the Rmax to ≤20μ. If Tp₅₀ exceeds 70%, the sufficient adhesion property is not obtainable.;COPYRIGHT: (C)1998,JPO