Abstract: A round steel rod having a carbon content between 0.30 and 0.60% is processed by a cold working process to form a flat wire for forming a ring gear. The cold working process forms a semifinished flat wire by at least one cold rolling or cold roller drawing step and at least one two-way or four-way rolling step. The semifinished flat wire is processed by die drawing using a drawing die to obtain a finished flat wire in a last stage of the cold working process. The cold working process reduces the round steel rod at a total area reduction of 65% or below.

Abstract: The present invention provides a production method for fuel cell separator, including: preparing a material plate made of stainless steel; press forming the material plate, so that the material plate has a cross section having a concavo-convex shape; and plating only convex of the concavo-convex shape of the material plate with a conductive metal, wherein in the plating, a plating solution holding member, having a plating solution including an ion of the conductive metal, is prepared, the plating solution holding member contacts only the convex, and current is supplied between the solution holding member and the material plate, and in the plating, hydrogen is generated on a surface of the material plate, a passivation film formed on the surface of the material plate is reduced by the hydrogen, and the material plate is plated with the conductive metal.

Abstract: By a press-formed starting member (11) being immersed in a process liquid (12) at 40 to 60° C. and of pH 9 to 12, a passive film (26) is formed at the surface of the press-formed starting member. There is no solving out of metal ions from the press-formed starting member, and the passivation treatment can be carried out by just immersion in a single solution, so that costs including waste processing can be reduced. In another aspect, degreasing, cleaning and passivation treatment are carried out by spraying the press-formed starting member. By the use of spraying, the degreasing, cleaning and passivation treatment can be made rapid, and the amounts of process liquid needed for degreasing, cleaning and passivation treatment can be reduced.

Abstract: A round steel rod having a carbon content between 0.30 and 0.60% is processed by a cold working process to form a flat wire for forming a ring gear. The cold working process forms a semifinished flat wire by at least one cold rolling or cold roller drawing step and at least one two-way or four-way rolling step. The semifinished flat wire is processed by die drawing using a drawing die to obtain a finished flat wire in a last stage of the cold working process. The cold working process reduces the round steel rod at a total area reduction of 65% or below.

Abstract: A fuel cell separator manufacturing method including the steps of removing an abnormal layer (91) arising at the surface layer of a metal material for use as a separator (20) when it is rolled, exposing portions of conductors (92) included in a surface layer part of the metal material itself to project, and carrying out a passivation treatment on the surface layer part of the metal material itself. The steps of removing the abnormal layer and exposing portions of the conductors are possible in the same process, chemically or electro-chemically. Therefore, the number of steps can be cut and increased productivity and reduced cost of separators can be achieved.

Abstract: A composite nickel and copper alloy plating film (3) containing nickel and copper. Nickel is of high wear resistance and a nickel alloy improves the wear resistance of the film. Copper is of high corrosion resistance and a copper alloy improves the corrosion resistance of the film. The film may further contain self-lubricating particles and hard particles which ensure its wear resistance and lubricating property to a further extent.

Abstract: A composite nickel and copper alloy plating film (3) containing nickel and copper. Nickel is of high wear resistance and a nickel alloy improves the wear resistance of the film. Copper is of high resistance of the film. The film may further contain self-lubricating particles and hard particles which ensure its wear resistance and lubricating property to a further extent.

Abstract: By a press-formed starting member (11) being immersed in a process liquid (12) at 40 to 60° C. and of pH 9 to 12, a passive film (26) is formed at the surface of the press-formed starting member. There is no solving out of metal ions from the press-formed starting member, and the passivation treatment can be carried out by just immersion in a single solution, so that costs including waste processing can be reduced. In another aspect, degreasing, cleaning and passivation treatment are carried out by spraying the press-formed starting member. By the use of spraying, the degreasing, cleaning and passivation treatment can be made rapid, and the amounts of process liquid needed for degreasing, cleaning and passivation treatment can be reduced.

Abstract: A fuel cell separator manufacturing method including the steps of removing an abnormal layer (91) arising at the surface layer of a metal material for use as a separator (20) when it is rolled, a exposing portions of conductors (92) included in a surface layer part of the metal material itself to project, and carrying out a passivation treatment on the surface layer part of the metal material itself. The steps of removing the abnormal layer and exposing portions of the conductors are possible in the same process, chemically or electro-chemically. Therefore, the number of steps can be cut and increased productivity and reduced cost of separators can be achieved.

Abstract: A composite nickel and copper alloy plating film (3) containing nickel and copper. Nickel is of high wear resistance and a nickel alloy improves the wear resistance of the film. Copper is of high resistance of the film. The film may further contain self-lubricating particles and hard particles which ensure its wear resistance and lubricating property to a further extent.

Abstract: A composite plating apparatus includes a cylindrical electrode which is positioned in a hollow section of a workpiece with a surrounding gap left therebetween. A plurality of through-holes are formed across the thickness of an outer wall of the cylindrical electrode. Composite plating liquid is jetted out through the through-holes and impinge on the inner surface of the hollow section to thereby produce turbulence. The turbulent liquid provides a uniform distribution of ceramic particles in the liquid. As a result, the ceramic particles can be co-deposited uniformly in a metallic matrix, and hence a uniform abrasion-resistant characteristic is obtained all over a resultant composite plating film.

Abstract: In a disclosed composite plating method for a hollow member, an insertion electrode is loosely inserted with a space into a cylinder of a hollow member, a composite plating solution supplied from a solution supply pipe is circulated into the space of the cylinder, a base metal electrode is connected to the hollow member and composite plating is applied onto the inner peripheral surface of the hollow member. The current density between the insertion electrode and the inner peripheral surface of the hollow member is set at a low value at the beginning and is increased after a lapse of a predetermined time. More preferably, bubbles are produced by supplying gas into the composite plating solution almost simultaneously with the above-mentioned increase of the current density.

Abstract: An electrically conductive layer is formed on a surface of a model, and an organic solvent layer of an organic solvent which is inactive with respect to the conductive layer is formed on a surface of the conductive layer. Particles are then placed on the organic solvent layer to allow the particles to be partly melted by the organic solvent layer, and the organic solvent layer is removed to allow the particles to be adhered to the conductive layer. A metal layer is deposited on the model in an electroforming process to form an electroformed shell thinner than the diameter of the particles. The electroformed shell is separated from the model, and the particles are dissolved away from the electroformed shell with an organic solvent to produce an electroformed object having a number of vent apertures.

Abstract: A heat treating process for a rod by the use of a fluidized bed consisting of alumina, silicon sand, zircon sand, and the like, is disclosed for adjusting the strength of the rod due to its cooling within the fluidized bed. While prior art heat treatment processes of this type adopt an attempt to vary the temperature of the fluidized bed for varying the cooling rate of the rod, such results in the need to use costly heat-resisting apparatus for the fluidized bed and equipment associated therewith. In accordance with the heat treatment process of the present invention, a rod is introduced through means of an inlet opening into the fluidized bed, and subsequently, the rod passes through the fluidized bed in an upwardly inclined manner so as to exit from the surface of the bed. The fluidized bed in this case has a predetermined length and the rod is fed at a predetermined speed.