Claims
- 1. A method for producing a diesel engine valve comprising the steps of:
- forging a raw material of the high corrosion resisting alloy into a valve shape of the diesel engine, wherein said high corrosion resisting alloy consists by weight percentage of not more than 0.1% of C, not more than 1.0% of Si, not more than 1.0% of Mn, more than 25% and not more than 32% of Cr, more than 2.0% and not more than 3.0% of Ti, 1.0 to 2.0% of Al, and the balance being Ni plus incidental impurities;
- subjecting the obtained valve shaped forging to aging treatment; and
- partially enhancing hardness of the valve by subjecting at least part of the aging treated forging to cold working.
- 2. A method for producing a diesel engine valve comprising the steps of:
- forging a raw material of the high corrosion resisting alloy into a valve shape of the diesel engine, wherein said high corrosion resisting alloy consists by weight percentage of not more than 0.1% of C, not more than 1.0% of Si, not more than 1.0% of Mn, more than 25% and not more than 32% of Cr, more than 2.0% and not more than 3.0% of Ti, 1.0 to 2.0% of Al, and the balance being Ni plus incidental impurities wherein Fe and Co as said impurities are controlled to not more than 3.0% and 2.0%, respectively;
- subjecting the obtained valve shaped forging to an optional solid solution treatment and to an aging treatment; and
- partially enhancing hardness of the valve by subjecting at least part of the aging treated forging to cold working.
- 3. A method for producing a diesel engine valve comprising the steps of:
- forging a raw material of the high corrosion resisting alloy according to claim 1 wherein said alloy further contains one or both of not more than 0.02% of B and not more than 0.15% of Zr, into a valve shape of the diesel engine;
- subjecting the obtained valve shaped forging to an optional solid solution treatment and to an aging treatment; and
- partially enhancing hardness of the valve by subjecting at least part of the aging treated forging to cold working.
- 4. A method for producing a diesel engine valve comprising the steps of:
- forging a raw material of the high corrosion resisting alloy according to claim 2 into a valve shape of the diesel engine;
- subjecting the obtained valve shaped forging to an optional solid solution treatment and to an aging treatment; and
- partially enhancing hardness of the valve by subjecting at least part of the aging treated forging to cold working.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9-39937 |
Jul 1997 |
JPX |
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Parent Case Info
This is a divisional of application Ser. No. 09/017,877 filed Feb. 3, 1998, now U.S. Pat. No. 6,039,919, the disclosure of which is incorporated herein by reference.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4741080 |
Larson et al. |
May 1988 |
|
Foreign Referenced Citations (1)
Number |
Date |
Country |
273532 |
Oct 1984 |
AUX |
Divisions (1)
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Number |
Date |
Country |
Parent |
017877 |
Feb 1998 |
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