Method for producing surface-hardened material
AssigneeNihon Parkerizing Co., Ltd.
InventorsRyu Nakajima, Taro Ito, Tatsuya Matsukawa, Masaaki Beppu
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Abstract
A method for producing a surface-hardened material, comprising: an immersion step of immersing an iron steel material having nitrogen attached in the form of a solid solution on the surface thereof in a melt containing a chloride at a temperature ranging from 650° C. to 900° C.; and a cooling step of cooling the immersed iron steel material to a temperature equal to or lower than a martensitic transformation start temperature at a cooling rate equal to or higher than a lower critical cooling rare at which martensitic transformation starts.
Claims5
A method for producing a surface-hardened material, comprising:
- an immersion step of immersing a steel material of which a surface is in a form of a solid solution of nitrogen in a molten material containing a chloride within a range of 650° C. to 900° C.;
- and
- a cooling step of cooling the immersed steel material to a martensitic transformation starting temperature or less at a cooling rate equal to or higher than a lower critical cooling rate at which martensitic transformation starts.
Dependencies are inferred from the claim text.