An apparatus for removing paint from a metallic component. The apparatus includes an electrolytic cell in which the metallic component is an anode, and a DC power supply capable of producing a plasma causing the paint from the metallic component to disintegrate. A method of depainting a metallic component includes providing an electrolytic cell with the metallic component to be depainted acting as an anode. A DC power supply connected to the cathode and anode is activated to produce a plasma causing the paint from the metallic component to disintegrate. Another method of method of depainting a metallic component includes providing an aqueous solution of sodium hydrogen carbonate, sodium citrate, and potassium oxalate as an electrolyte, a cathode and a pained metallic component as an anode. A DC power supply connected to the cathode and anode produces a plasma causing the paint from the painted metallic component to disintegrate.

An apparatus for removing paint from a metallic component. The apparatus includes an electrolytic cell in which the metallic component is an anode, and a DC power supply capable of producing a plasma causing the paint from the metallic component to disintegrate. A method of depainting a metallic component includes providing an electrolytic cell with the metallic component to be depainted acting as an anode. A DC power supply connected to the cathode and anode is activated to produce a plasma causing the paint from the metallic component to disintegrate. Another method of method of depainting a metallic component includes providing an aqueous solution of sodium hydrogen carbonate, sodium citrate, and potassium oxalate as an electrolyte, a cathode and a pained metallic component as an anode. A DC power supply connected to the cathode and anode produces a plasma causing the paint from the painted metallic component to disintegrate.

The present invention is a method of metal polishing and oxidation film process applied on a metal workpiece. The process comprises (a) providing the metallic workpiece in an electrolysis polishing liquid; (b) a temperature control device controlling a liquid temperature of the electrolysis polishing liquid; (c) a voltage supply device to exercising an operating voltage between the metallic workpiece and the electrolysis polishing liquid; (d) polishing the surface of the metallic workpiece and forming an oxidation layer by regulating the temperature control device and the voltage supply device; and (e) determining a film thickness of the oxidation layer formed on the metallic workpiece according to an operation time, wherein the film thickness is related to a roughness and a color displayed on the metallic workpiece. The metallic workpiece may be dyed together during the polishing process without adding any dyes. The present invention further provides a system of alloy oxidation film process.

The present invention is a method of metal polishing and oxidation film process applied on a metal workpiece. The process comprises (a) providing the metallic workpiece in an electrolysis polishing liquid; (b) a temperature control device controlling a liquid temperature of the electrolysis polishing liquid; (c) a voltage supply device to exercising an operating voltage between the metallic workpiece and the electrolysis polishing liquid; (d) polishing the surface of the metallic workpiece and forming an oxidation layer by regulating the temperature control device and the voltage supply device; and (e) determining a film thickness of the oxidation layer formed on the metallic workpiece according to an operation time, wherein the film thickness is related to a roughness and a color displayed on the metallic workpiece. The metallic workpiece may be dyed together during the polishing process without adding any dyes. The present invention further provides a system of alloy oxidation film process.

Stainless steel for a fuel cell separator plate and a manufacturing method therefor are disclosed. The stainless steel for a fuel cell separator plate, according to one embodiment of the present invention, comprises: a stainless base material; and a passive film formed on the stainless base material, wherein a Cr/Fe atomic weight ratio in a 1 nm or less thickness region of the stainless base material, which is adjacent to an interface between the stainless and the passive film, is 0.45 or more. Therefore, by modifying the surface of the stainless steel for a fuel cell separator plate, a low interface contact resistance and a good corrosion resistance can be obtained, and a separate additional process such as precious metal coating can be removed, such that manufacturing costs are reduced and productivity can be improved.

Stainless steel for a fuel cell separator plate and a manufacturing method therefor are disclosed. The stainless steel for a fuel cell separator plate, according to one embodiment of the present invention, comprises: a stainless base material; and a passive film formed on the stainless base material, wherein a Cr/Fe atomic weight ratio in a 1 nm or less thickness region of the stainless base material, which is adjacent to an interface between the stainless and the passive film, is 0.45 or more. Therefore, by modifying the surface of the stainless steel for a fuel cell separator plate, a low interface contact resistance and a good corrosion resistance can be obtained, and a separate additional process such as precious metal coating can be removed, such that manufacturing costs are reduced and productivity can be improved.

A forming method includes: forming a formed article including a first part and a second part using a first metal for the first part and a second metal for the second part; and removing the second part from the formed article by immersing the formed article in an electrolyte solution and causing a current to flow in the second part.

A forming method includes: forming a formed article including a first part and a second part using a first metal for the first part and a second metal for the second part; and removing the second part from the formed article by immersing the formed article in an electrolyte solution and causing a current to flow in the second part.

A forming method includes: forming a formed article including a first part and a second part using a first metal for the first part and a second metal for the second part; and removing the second part from the formed article by immersing the formed article in an electrolyte solution and causing a current to flow in the second part.

An etching apparatus having a liquid bath storing an etching liquid, a substrate installation part capable of supporting the semiconductor substrate in vertical placement at a position at which a treatment surface of the semiconductor substrate is immersed in the etching liquid, a sample electrode provided at the substrate installation part and electrically connected to the semiconductor substrate, a counter electrode disposed at a position at which the counter electrode is immersed in the etching liquid in the liquid bath, a light source irradiating the treatment surface of the semiconductor substrate with light, and an irradiation window provided between the treatment surface of the semiconductor substrate and the light source and at a position separated from the semiconductor substrate in a horizontal direction.