Steel Material, Process of Fabricating Steel Material, and Apparatus of Fabricating Steel Material
First Claim
1. A process of fabricating a steel material by performing a heat treatment to a steel material having high strength, in order to reduce hardness at one part of the steel material to less than hardness at other parts of the steel material,wherein the heat treatment comprises a heating step for rapidly heating a portion from a surface of the steel material to a certain depth by induction heating or direct energization heating, and a cooling step for rapidly cooling the steel material subjected to the heating step after a predetermined time from the heating step, anda heating temperature in the heating step is Ac1 transforming point or more.
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Accused Products
Abstract
According to one aspect of the present invention, there is provided a process of fabricating a steel material by performing a heat treatment to a steel material having high strength, in order to reduce hardness at one part of the steel material to less than hardness at other parts of the steel material, wherein the heat treatment comprises a heating step in which a portion having a certain depth from a surface of the steel material is rapidly heated by induction heating or direct energization heating, and a cooling step in which the steel material, which has been subject to the heating step, is rapidly cooled a predetermined time after the heating step, and a heating temperature in the heating step is Ac1 transforming point or more.
7 Citations
17 Claims
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1. A process of fabricating a steel material by performing a heat treatment to a steel material having high strength, in order to reduce hardness at one part of the steel material to less than hardness at other parts of the steel material,
wherein the heat treatment comprises a heating step for rapidly heating a portion from a surface of the steel material to a certain depth by induction heating or direct energization heating, and a cooling step for rapidly cooling the steel material subjected to the heating step after a predetermined time from the heating step, and a heating temperature in the heating step is Ac1 transforming point or more.
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16. An apparatus of fabricating a steel material that performs a heat treatment to a steel material having high strength, in order to reduce hardness at one part of the steel material to less than hardness at other parts of the steel material, the apparatus comprising:
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a heating unit configured to rapidly heat a portion from a surface of the steel material to a certain depth by induction heating or direct energization heating; and a cooling unit configured to rapidly cool the steel material subjected to the heating after a predetermined time from the heating, wherein a heating temperature of the steel material by the heating unit is Ac1 transforming point or more. - View Dependent Claims (17)
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Specification