A method for providing a surface finish to a metal part includes both diffusion hardening a metal surface to form a diffusion-hardened layer, and oxidizing the diffusion-hardened layer to create an oxide coating thereon. The diffusion-hardened layer can be harder than an internal region of the metal part and might be ceramic, and the oxide coating can have a color that is different from the metal or ceramic, the color being unachievable only by diffusion hardening or only by oxidizing. The metal can be titanium or titanium alloy, the diffusion hardening can include carburizing or nitriding, and the oxidizing can include electrochemical oxidization. The oxide layer thickness can be controlled via the amount of voltage applied during oxidation, with the oxide coating color being a function of thickness. An enhanced hardness profile can extend to a depth of at least 20 microns below the top of the oxide coating.

The present invention discloses a metal sulfurization device using a single furnace, comprising an internal quartz tube unit; an external quartz tube unit that is located outside the internal quartz tube unit; a single furnace that is outside the external quartz tube unit and is movable along the outside of the external quartz tube unit; and a single furnace location control unit that is capable of controlling a position of the single furnace, wherein the internal quartz tube part includes: a sulfur source part that supplies sulfur powder; a substrate part on which metal is deposited; a distance control part that is capable of controlling a distance between the sulfur source part and the substrate part; and a gas supply part that injects gas from the sulfur source part toward the substrate part.

The present invention discloses a metal sulfurization device using a single furnace, comprising an internal quartz tube unit; an external quartz tube unit that is located outside the internal quartz tube unit; a single furnace that is outside the external quartz tube unit and is movable along the outside of the external quartz tube unit; and a single furnace location control unit that is capable of controlling a position of the single furnace, wherein the internal quartz tube part includes: a sulfur source part that supplies sulfur powder; a substrate part on which metal is deposited; a distance control part that is capable of controlling a distance between the sulfur source part and the substrate part; and a gas supply part that injects gas from the sulfur source part toward the substrate part.

A process comprising: placing a boronizing powder composition in the interior of a metal pipe comprising a first end, a second end, an inside surface and an outside surface; heating the pipe in a vessel having an interior, to a temperature from 1400 F. to 1900 F., thereby forming spent boronizing reaction gases and a borided layer on the inside surface, wherein the vessel interior has an atmosphere that surrounds the outside surface of the metal pipe; and flowing the spent boronizing reaction gases into the atmosphere surrounding the outside surface of the pipe, thereby forming an oxygen-depleted atmosphere.

Provided are an adhesion removal method capable of removing sulfur-containing adhesions that adhere onto the inner surface of a chamber or the inner surface of a pipe connected to the chamber without disassembly of the chamber and a film-forming method. Sulfur-containing adhesions adhering onto at least one of the inner surface of a chamber (10) and the inner surface of a discharge pipe (15) connected to the chamber (10) are removed by reaction with a cleaning gas containing an oxygen-containing compound gas.

Provided are an adhesion removal method capable of removing sulfur-containing adhesions that adhere onto the inner surface of a chamber or the inner surface of a pipe connected to the chamber without disassembly of the chamber and a film-forming method. Sulfur-containing adhesions adhering onto at least one of the inner surface of a chamber (10) and the inner surface of a discharge pipe (15) connected to the chamber (10) are removed by reaction with a cleaning gas containing an oxygen-containing compound gas.

A catalytic chemical vapor deposition apparatus comprising a catalyst wire including a tantalum wire and a boride layer formed on a surface of the tantalum wire is used. The boride of the metal tantalum (tantalum boride) is harder than the metal tantalum. Therefore, by using the tantalum wire having the boride layer formed on the surface thereof as a catalyst wire, it is possible to reduce thermal expansion of the catalyst wire, improve mechanical strength, and prolong the service life. Further, by performing energization heating of the catalyst wire by continuous energization, it is further possible to prolong the service life of the catalyst wire.

A catalytic chemical vapor deposition apparatus comprising a catalyst wire including a tantalum wire and a boride layer formed on a surface of the tantalum wire is used. The boride of the metal tantalum (tantalum boride) is harder than the metal tantalum. Therefore, by using the tantalum wire having the boride layer formed on the surface thereof as a catalyst wire, it is possible to reduce thermal expansion of the catalyst wire, improve mechanical strength, and prolong the service life. Further, by performing energization heating of the catalyst wire by continuous energization, it is further possible to prolong the service life of the catalyst wire.

An aluminum alloy member forms a fluoride film thereon, which does not form a black dot-shaped bulged portion and, therefore, has excellent smoothness and excellent corrosion resistance against a corrosive gas, plasma, and others. An aluminum alloy member for forming a fluoride film thereon, consists of: Si: 0.01 mass % to 0.3 mass %; Mg: 0.5 mass % to 5.0 mass %; Fe: 0.05 mass % to 0.5 mass %; Cu: 0.5 mass % or less; Mn: 0.30 mass % or less; Cr: 0.30 mass % or less, and the balance being Al and inevitable impurities, wherein when an average major diameter of Fe-based crystallized products in the aluminum alloy member is D (m), and an average crystalline particle diameter in the aluminum alloy member is Y (m), a relational expression: Log.sub.10 Y<0.320D+4.60 . . . (1) is satisfied. A fluoride film is formed on at least a part of a surface of the aluminum alloy.

A test piece preparation step of preparing a test piece (50) including a welding structure in which a welding material formed of an austenitic alloy is welded to a member formed of low-alloy steel or low-carbon steel, a hydrogen supply step of supplying hydrogen to the test piece (50), and a characteristic stress acquisition step of applying a load (F) to the test piece (50) to which hydrogen was supplied and acquiring a characteristic stress showing material mechanical properties of the test piece (50) are executed.