Vacuum carburizing method and device, and carburized products
AssigneeJH Corporation
InventorKen Kubota
Life of this patent
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Abstract
In order to keep down soot production and to enable every part of the workpiece, including deep concavities to be uniformly carburized by vacuum carburizing, and to enable decreases in the quantities of gas and heat employed, carburizing treatment is performed in the heating chamber 2 of a vacuum carburizing furnace 1 with workpieces M being heated while acetylene gas is supplied from a carburizing gas source C inside the heating chamber 2, and the inside of the heating chamber 2 being evacuated by a vacuum evacuation source V to give a vacuum of .ltoreq.1 kPa.
Claims8
A vacuum carburizing method which is a vacuum carburizing method in which carburizing treatment is performed by vacuum heating workpieces from steel material in the heating chamber of a vacuum carburizing furnace, and supplying a carburizing gas to the heating chamber, comprising employing a gaseous unsaturated aliphatic hydrocarbon comprising an acetylenic gas as said carburizing gas, and performing said carburizing treatment with the heating chamber at a vacuum of not more than 1 kPa.
A vacuum carburizing device comprising a vacuum carburizing furnace provided with a heating chamber for heating workpieces comprising steel material, a carburizing gas source which supplies an acetylenic gas into said heating chamber, and a vacuum evacuation source which evacuates said heating chamber to a pressure of not more than 1 kPa, wherein said vacuum carburizing is performed at not more than 1 kPa.
A carburized steel product which is a steel product provided with closed concavities in which the inside walls of said concavities are carburized having an inner diameter D and a depth L of a region over which the carburized case depth in the inner walls of the aforementioned closed holes is almost uniform characterized in that a ratio of L/D is in the range of 12-50.
A vacuum carburizing method which is a vacuum carburizing method in which carburizing treatment is performed by vacuum heating workpieces from steel material in the heating chamber of a vacuum carburizing furnace, and supplying a carburizing gas to the heating chamber, comprising employing a gaseous unsaturated aliphatic hydrocarbon comprising an acetylenic gas as said carburizing gas, and performing said carburizing treatment with the heating chamber at a vacuum of not more than 0.5 kPa.
A vacuum carburizing device comprising a vacuum carburizing furnace provided with a heating chamber for heating workpieces comprising steel material, a a carburizing gas source which supplies an acetylenic gas into said heating chamber, and a vacuum evacuation source which evacuates said heating chamber to a pressure of not more than 0.5 kPa, wherein said vacuum carburizing is performed at not more than 0.5 kPa.
Dependencies are inferred from the claim text.