Pure titanium sheet excellent in balance between stamping formability and strength

Patent metadata

Field	Value
Publication number	US-9353432-B2
Application number	US-201213350057-A
Country	US
Kind code	B2
Filing date	Jan 13, 2012
Priority date	Jan 28, 2011
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

Disclosed is a pure titanium sheet having a strength corresponding to JIS Grade 2 level (215 MPa in terms of 0.2% yield strength) or more and having satisfactory stamping formability. The pure titanium sheet includes titanium and inevitable impurities, has a 0.2% yield strength of 215 MPa or more, has an average grain size d of its structure of 25 μm or more and 75 μm or less, and has a hexagonal crystal structure, in which respective grains in the hexagonal crystal structure have an average of Schmidt factors (SF) of (11-22) twins with a rolling direction as axes, and the average Schmidt factor (SF) and the average grain size d satisfy following Expression (1):

0.055≦[SF/√ d ]≦0.084  (1).

First claim

What is claimed is:

1. A pure titanium sheet comprising titanium and inevitable impurities, the pure titanium sheet having a 0.2% yield strength of 215 MPa or more, the pure titanium sheet having an average grain size d of its structure of 25 μm or more and 75 μm or less, and the pure titanium sheet having a hexagonal crystal structure, respective grains in the hexagonal crystal structure having an average of Schmidt factors (SF) of (11-22) twins with a rolling direction as axes, and the average Schmidt factor (SF) and the average grain size d satisfying following Expression (1):
0.055≦[SF/ √{square root over (d)}]≦ 0.084  (1).

2. A plate heat exchanger comprising the titanium sheet of claim 1 as a constituent.

3. The pure titanium sheet of claim 1 , which has an average grain size d of its structure of 30 μm to 65 μm.

4. A plate heat exchanger comprising the pure titanium sheet of claim 3 as a constituent.

5. The pure titanium sheet of claim 1 , which has an average grain size d of 35 μm to 55 μm.

6. A plate heat exchanger comprising the pure titanium sheet of claim 5 as a constituent.

7. The pure titanium sheet of claim 1 , the average Schmidt factor (SF) and the average grain size d satisfying following Expression (1):
0.058≦[SF/ √{square root over (d)}]≦ 0.081  (1).

8. A plate heat exchanger comprising the pure titanium sheet of claim 7 as a constituent.

9. The pure titanium sheet of claim 1 , the average Schmidt factor (SF) and the average grain size d satisfying following Expression (1):
0.061≦[SF/ √{square root over (d)}]≦ 0.078  (1).

10. A plate heat exchanger comprising the pure titanium sheet of claim 9 as a constituent.

11. The pure titanium sheet of claim 1 , where the inevitable impurities are N: 0.03 percent by mass or less, C: 0.08 percent by mass or less, H: 0.013 percent by mass or less, Fe: 0.25 percent by mass or less, and O: 0.20 percent by mass or less.

12. A plate heat exchanger comprising the pure titanium sheet of claim 11 as a constituent.

13. The pure titanium sheet of claim 1 , where the inevitable impurities are N: 0.05 percent by mass or less, C: 0.08 percent by mass or less, H: 0.013 percent by mass or less, Fe: 0.30 percent by mass or less, and O: 0.30 percent by mass or less.

14. A plate heat exchanger comprising the pure titanium sheet of claim 13 as a constituent.

15. The pure titanium sheet of claim 1 , where the inevitable impurities are N: 0.03 percent by mass or less, C: 0.08 percent by mass or less, H: 0.015 percent by mass or less, Fe: 0.20 percent by mass or less, and O: 0.18 percent by mass or less.

16. A plate heat exchanger comprising the pure titanium sheet of claim 15 as a constituent.

17. The pure titanium sheet of claim 1 , where the inevitable impurities are N: 0.03 percent by mass or less, C: 0.08 percent by mass or less, H: 0.015 percent by mass or less, Fe: 0.30 percent by mass or less, and O: 0.25 percent by mass or less.

18. A plate heat exchanger comprising the pure titanium sheet of claim 17 as a constituent.

Assignees

• Fujita Akihisa
• Itsumi Yoshio
• Oyama Hideto
• Kudo Takeshi
• Murakami Shogo
• Kobe Steel Ltd

Inventors

• Fujita Akihisa
• Itsumi Yoshio
• Oyama Hideto
• Kudo Takeshi
• Murakami Shogo

Classifications

• C22F1/183 Primary

  of titanium or alloys based thereon · CPC title

• C22C14/00

  Alloys based on titanium · CPC title

• F17D5/02

  Preventing, monitoring, or locating loss · CPC title

• F28F21/086

  from titanium or titanium alloys · CPC title

• G01M3/007 Primary

  Leak detector calibration, standard leaks (G01M3/207 takes precedence) · CPC title