Stainless steel coated with thin film of carbon containing specified amount in a state of diamond and having an adjustable black transparent color tone

摘要

A stainless steel with black transparent appearance suitable for use as a decorative architectural material. The stainless steel material has a stainless steel substrate and a thin graphite film formed on the substrate, the thin graphite film having a thickness not greater than 1 . mu.m and containing 10 to 75 wt % of carbon existing in a state of diamond. This stainless steel material is produced by chemical vapor deposition process making use of a capacitance-coupled type high- frequency plasma, having the steps of preparing a stainless steel material as a substrate; placing the substrate in an atmosphere of a mixture gas which contains both hydrogen gas and an inert gas together with a hydrocarbon gas; and causing a reaction by applying a D.C. voltage of 100 to 600 V using the substrate as a cathode; thereby forming, on the substrate, a thin graphite film having a thickness not greater than 1 &mgr; m and containing 10 to 75 wt % of carbon existing in a state of diamond.