Hard film and method for forming same, and die for use in hot forming of steel sheet

Patent metadata

Field	Value
Publication number	US-10233530-B2
Application number	US-201515120285-A
Country	US
Kind code	B2
Filing date	Feb 16, 2015
Priority date	Mar 3, 2014
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

Abstract

Disclosed is a hard film based on tungsten carbide excellent in wear resistance, wherein the composition of the film is defined by W1-x-yCxMy, where 0.01≤y≤0.2, 0.50≤x/(1−x−y)≤4.0, and M is one or more selected from Co, Ni, Fe and Cu.

First claim

The invention claimed is:

1. A hard film based on tungsten carbide having a composition defined by W 1-x-y C x M y , where 0.01≤y≤0.05, 0.50≤x/(1−x−y)≤4.0, and M is one or more metal elements selected from the group consisting of Co, Fe and Cu.

2. The hard film according to claim 1 , wherein the film is formed on an adhesion layer formed on a surface of a substrate and comprising an intermediate layer, which has a thickness of 1 μm or more and consists of a nitride, a carbonitride or a carbide of one or more elements selected from the group consisting of a Group 4 element, a Group 5 element, a Group 6 element, Al and Si.

3. The hard film according to claim 2 , wherein
the adhesion layer further comprises a multilayered film laminated on the intermediate layer, and
the multilayered film is formed by alternately laminating a film consisting of one or more elements selected from the group consisting of W, C, Co, Ni, Fe and Cu, and a film consisting of one or more elements selected from the group consisting of a Group 4 element, a Group 5 element, a Group 6 element, Al and Si.

4. The hard film according to claim 2 , wherein
the adhesion layer further comprises a metal layer formed on the intermediate layer,
the intermediate layer consists of CrN, and
the metal layer consists of Cr.

5. The hard film according to claim 2 , wherein
the adhesion layer further comprises a metal layer formed on the intermediate layer, and
the metal layer has a thickness of 50 nm or more and consists of one or more elements selected from the group consisting of a Group 4 element, a Group 5 element, a Group 6 element, Al and Si.

6. The hard film according to claim 1 , wherein
the film is formed on an adhesion layer comprising a metal layer, which has a thickness of 50 nm or more and consists of one or more elements selected from the group consisting of a Group 4 element, a Group 5 element, a Group 6 element, Al and Si.

7. The hard film according to claim 6 , wherein the adhesion layer further comprises a multilayered film laminated on the metal layer, and
the multilayered film is formed by alternately laminating a film consisting of one or more elements selected from the group consisting of W, C, Co, Ni, Fe and Cu, and a film consisting of one or more elements selected from the group consisting of a Group 4 element, a Group 5 element, a Group 6 element, Al and Si.

8. The hard film according to claim 7 , wherein
the adhesion layer further comprises an intermediate layer having a thickness of 1 μm or more and consisting of a nitride, a carbonitride or a carbide of one or more elements selected from the group consisting of a Group 4 element, a Group 5 element, a Group 6 element, Al and Si; and
the metal layer is formed on the intermediate layer.

9. A die for hot forming a steel sheet, wherein the hard film according to claim 1 is formed on a surface of the die.

10. A method for forming the hard film according to claim 1 , the method comprising:
forming the hard film by a cathode-type arc ion plating method using a target consisting of W, C and the one or more metal elements M.

Assignees

• Kobe Steel Ltd
• Kobe Steel Ltd

Inventors

• Yamamoto Kenji
• Takazawa Tomoyasu
• Miura Katsutomo

Classifications

• C23C28/34

  including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates · CPC title

• C23C28/321

  with at least one metal alloy layer · CPC title

• C23C28/36

  including layers graded in composition or physical properties · CPC title

• C23C28/3455

  with a refractory ceramic layer, e.g. refractory metal oxide, ZrO2, rare earth oxides or a thermal barrier system comprising at least one refractory oxide layer · CPC title

• C23C14/0688 Primary

  Cermets, e.g. mixtures of metal and one or more of carbides, nitrides, oxides or borides · CPC title