Hot working die steel and member comprising the same for high-temperature use

• US 6,117,388 A
• Filed: 03/05/1999
• Issued: 09/12/2000
• Est. Priority Date: 09/02/1998
• Status: Expired due to Term

• Current Assignee: Japan Steel Works Limited
• Original Assignee: Japan Steel Works Limited
• Inventors: Shibata, Takashi, Maeda, Eiji
• Primary Examiner(s): Yee, Deborah
• Application Number:
  US09/262,843
• Time in Patent Office: 557 Days
• Field of Search: 420/37, 420/38, 420/107, 420/69, 148/105, 148/325, 148/330, 148/333
• US Class Current: 420/37
• CPC Class Codes: C22C 38/44 with molybdenum or tungsten
• CPC Class Codes: C22C 38/46 with vanadium
• CPC Class Codes: C22C 38/48 with niobium or tantalum
• CPC Class Codes: C22C 38/52 with cobalt

Abstract

Alloy steel containing 0.10 to 0.50 wt % of C, 0.5 wt % or less of Si, 1.5 wt % or less of Mn, 1.5 wt % or less of Ni, 3.0 to 13.0 wt % of Cr, 0 to 3.0 wt % of Mo, 1.0 to 8.0 wt % of W, 0.01 to 1.0 wt % of V, 0.01 to 1.0 wt % of Nb, 1.0 to 10.0 wt % of Co, 0.003 to 0.04 wt % of B, and 0.005 to 0.05 wt % of N, the balance comprising Fe and unavoidable impurities.

Claims

1. Hot working die steel comprising:

0.10 to 0.50% by weight of C, 0.5% by weight or less of Si, 1.5% by weight or less of Mn, 1.5% by weight or less of Ni, 3.0 to 13.0% by weight of Cr, 0 to 3.0% by weight of Mo, 1.0 to 8.0% by weight of W, 0.01 to 1.0% by weight of V, 0.01 to 1.0% by weight of Nb, 1.0 to 10.0% by weight of Co, 0.003 to 0.04% by weight of B, and 0.005 to 0.05% by weight of N, the balance including Fe and unavoidable impurities.

2. Hot working die steel according to claim 1 further comprising:

one or more of 0.001 to 0.05% by weight of a rare earth metal, 0.001 to 0.05% by weight of Mg, and 0.001 to 0.05% by weight of Ca.

3. Hot working die steel according to claim 1, wherein the total content of Co and W is 5.0% by weight or more.

4. Hot working die steel according to claim 2, wherein the total content of Co and W is 5.0% by weight or more.

5. Hot working die steel according to claim 1, wherein the B to N ratio ranges from 0.2 to 1.0, and the total content of B and N is 0.05% by weight or less.

6. Hot working die steel according to claim 2, wherein the B to N ratio ranges from 0.2 to 1.0, and the total content of B and N is 0.05% by weight or less.

7. Hot working die steel according to claim 3, wherein the B to N ratio ranges from 0.2 to 1.0, and the total content of B and N is 0.05% by weight or less.

8. Hot working die steel according to claim 4, wherein the B to N ratio ranges from 0.2 to 1.0, and the total content of B and N is 0.05% by weight or less.

9. Hot working die steel according to claim 1, wherein the total amount of all alloying elements except Fe is 15.0% by weight or more.

10. Hot working die steel according to claim 2, wherein the total amount of all alloying elements except Fe is 15.0% by weight or more.

11. Hot working die steel according to claim 3, wherein the total amount of all alloying elements except Fe is 15.0% by weight or more.

12. Hot working die steel according to claim 4, wherein the total amount of all alloying elements except Fe is 15.0% by weight or more.

13. Hot working die steel according to claim 5, wherein the total amount of all alloying elements except Fe is 15.0% by weight or more.

14. Hot working die steel according to claim 6, wherein the total amount of all alloying elements except Fe is 15.0% by weight or more.

15. Hot working die steel according to claim 7, wherein the total amount of all alloying elements except Fe is 15.0% by weight or more.

16. Hot working die steel according to claim 8, wherein the total amount of all alloying elements except Fe is 15.0% by weight or more.

17. The member according to any one of claims 1 to 16 which is a casting die, a structural member for a casting machine, an injection die, a structural member for an injection molding machine, a hot forging die or an extrusion die.