Method for producing an internal combustion engine valve and valve obtained in this manner

US9181824B2 · kind B2 · utility

Assignee

• AUBERT & DUVAL · FR

Inventor

• Jacques Montagnon · Clermont-Ferrand, FR

Key dates

• Filing date: Jan 22, 2007
• Grant date: Nov 10, 2015
• Expiry date: Apr 2, 2030

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P10/25
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The invention concerns a method for making a unitary spark ignition valve, characterized in that it consists in preparing and casting a steel made up in wt. % of: 0.45%≦C 0.55%; 12%≦Cr≦18%; 1%≦Si≦2.5%; traces≦Mn≦2%; 0.2%≦V≦0.5%; traces≦Mo≦0.5%; 0.05%≦N≦0.15%, with 0.55%≦C+N≦0.70%; traces≦Ni≦1%; traces≦Cu≦0.25%, or Cu≦0.5 Ni if Cu>0.25%; traces≦Co≦1%; traces≦W≦0.2%; traces≦Nb≦0.15%; traces≦AI≦0.025%; traces≦Ti≦0.010%; traces≦S≦0.030%; traces≦P≦0.040%; traces≦B≦0.0050%; the balance being iron and impurities resulting from the preparation; in transforming by hot thermomechanical process, for example, by rolling and/or forging between 1000 and 1200° C.; optionally soft annealing, between 650 and 900° C. for 2 to 8 hours followed by air or furnace cooling; and performing the final thermal or thermomechanical treatments which will impart to the valve its shape and its final properties, including hot-shaping by forging or extrusion, and in a final manufacturing step a localized surface quenching, such as a high-frequency quenching, a plasma or a laser shock quenching, performed on certain parts of the valve. The invention also concerns a unitary spark ignition engine valve obtained by sai…