Carburization heat treatment method and method of use
AssigneesHyundai Motor Company, Kia Motors Corporation
InventorsBong Lae Jo, Chang Won Kang
Life of this patent
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Abstract
Disclosed is a carburization heat treatment method including carburizing a workpiece at a relatively low temperature within a temperature range of A1˜A3 using a vacuum carburizing furnace and then performing quenching using a high-pressure gas, in which the workpiece is made of typical carburizing alloy steel having a carbon content of about 0.10˜0.35 wt %. This method can be applied to carburization heat treatment of a steel workpiece sensitive to heat deformation, such as an annulus gear, in lieu of a conventional gas carburization method using plug quenching.
Claims6
A carburization heat treatment method of a vehicle workpiece sensitive to heat deformation, comprising:
- heating the workpiece to a carburizing temperature within a temperature range of A1˜A3;
- carburizing a surface of the workpiece in presence of a carburizing gas;
- and
- quenching the workpiece using a high-pressure gas so that the surface of the workpiece is formed with martensite and a core thereof is formed with a mixture of martensite and initial ferrite which is not subjected to phase transformation;
- wherein the workpiece is made of carburizing alloy steel, including chromium alloy steel, chromium-molybdenum alloy steel, or chromium-nickel-molybdenum alloy steel, each of which has a carbon content of 0.10˜0.35 wt %, and the method is conducted in a vacuum atmosphere using a vacuum carburizing furnace.
Dependencies are inferred from the claim text.