Claims
- 1. A method of hot rolling for iron and iron alloy rods, which comprises hot rolling iron or iron alloy rods having a diameter of 5 to 50 mm at a rolling speed of 2 m/sec or more using as a hot rolling tool a sintered body consisting essentially of .beta.-Si.sub.3 N.sub.4 as the main component and at least one sintering aid selected from the group consisting of Al.sub.2 O.sub.3, AlN, MgO, Y.sub.2 O.sub.3 and ZrO.sub.2, and having a sintered density of 90% or more, Rockwell hardness of 88 or more and a mean particle size of 2.mu. or less.
- 2. The method according to claim 1, wherein the sintered density is 97% or more, and the Rockwell hardness is 90 or more.
- 3. The method according to claim 2, wherein the tool has a mean bending strength of 50 kg/mm.sup.2 or more.
- 4. The method according to claim 1, wherein the tool has a mean bending strength of 50 kg/mm.sup.2 or more.
CROSS-REFERENCE TO RELATED APPLICATION
The present application is a continuation-in-part of Ser. No. 648,279 filed Sept. 7, 1984, now abandoned.
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Country |
2536354 |
Mar 1976 |
DEX |
53-216 |
Jul 1978 |
JPX |
112135 |
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JPX |
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Non-Patent Literature Citations (1)
Entry |
The Making, Shaping and Treating of Steel, seventh edition, United States Steel, 1957, pp. 678-679. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
648279 |
Sep 1984 |
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