Claims
- 1. A thermally treated Fe-based cast product which is produced by thermally treating an Fe-based cast product made by utilizing a thixocasting process using a Fe-based hypoeutectic casting material as a casting material, said thermally treated Fe-based cast product including a matrix and a large number of massive groups of fine α-grains dispersed in the matrix, said thermally treated Fe-based cast product having a thermally-treated texture where a large number of graphite phases are dispersed in said matrix and in each of said groups of fine α-grains, and said thermally treated Fe-based cast product having a free-cutting property such that a ratio B/A of an area rate B of the graphite phases in all said groups of fine α-grains to an area rate A of the graphite phases in the entire thermally-treated texture is in a range of B/A≧0.138.
- 2. A thermally treated Fe-based cast product having a free-cutting property according to claim 1, wherein said thermally treated Fe-based cast product comprises 1.8% by weight≦C≦2.5% by weight of carbon, 1.4% by weight≦Si≦3.0% by weight of silicon, 0.3% by weight≦Mn≦1.3% by weight of manganese and a balance of Fe including inevitable impurities.
- 3. A thermally treated Fe-based cast product which is produced by thermally treating a Fe-based cast product made from a thixocasting process using a Fe-based hypoeutectic casting material as a casting material, said thermally treated Fe-based cast product having a thermally treated microstructure comprising a matrix and a large number of groups of fine α-grains dispersed in the matrix, wherein said matrix and each of said groups of fine α-grains include graphite phases dispersed therein such that a ratio B/A of an area rate B of the graphite phases in all said groups of fine α-grains to an area rate A of the graphite phases in the entire thermally-treated microstructure is in a range of B/A≧0.138, said groups of fine α-grains are formed from the transformation of γ in portions of the Fe-based cast product that were formed from proeutectic γ, and said thermally treated Fe-based cast product having a Young's modulus greater than 180 GPa.
- 4. A thermally treated Fe-based cast product according to claim 3, wherein said thermally treated Fe-based cast product comprises carbon, silicon, manganese and a balance of Fe including inevitable impurities, and wherein the concentration of carbon, silicon, and manganese are set in the following ranges: 1.8% by weight≦C≦2.5% by weight, 1.4% by weight≦Si≦3.0% by weight, and 0.3% by weight≦Mn≦1.3% by weight.
Priority Claims (6)
Number |
Date |
Country |
Kind |
8-250953 |
Sep 1996 |
JP |
|
8-250954 |
Sep 1996 |
JP |
|
8-325957 |
Nov 1996 |
JP |
|
9-011993 |
Jan 1997 |
JP |
|
9-220704 |
Jan 1997 |
JP |
|
9-246233 |
Aug 1997 |
JP |
|
Parent Case Info
This application is a divisional application of Ser. No. 09/077,169 filed Nov. 9, 1998, now U.S. Pat. No. 6,136,101, which is a 371 of PCT/JP97/03058 filed Sep. 2, 1997.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
5858127 |
Ott et al. |
Jan 1999 |
A |
Foreign Referenced Citations (4)
Number |
Date |
Country |
1 564 275 |
Apr 1980 |
GB |
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Apr 1996 |
GB |
5-43978 |
Feb 1993 |
JP |
5-44010 |
Feb 1993 |
JP |
Non-Patent Literature Citations (3)
Entry |
Callister, William, “Materials Science and Engineering: an Introduction”, 3rd ed., (1994) pp 274, 275, 361.* |
JP 081 112661 Patent Abstract in English. |
Search Report. |