Aubert & Duval

Snecma Moteurs

Safran

Jacques Montagnon

Claude Marcel Mons

Philippe Heritier

Isabelle Peslerbe

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%&#x2266;C 0.55%; 12%&#x2266;Cr&#x2266;18%; 1%&#x2266;Si&#x2266;2.5%; traces&#x2266;Mn&#x2266;2%; 0.2%&#x2266;V&#x2266;0.5%; traces&#x2266;Mo&#x2266;0.5%; 0.05%&#x2266;N&#x2266;0.15%, with 0.55%&#x2266;C+N&#x2266;0.70%; traces&#x2266;Ni&#x2266;1%; traces&#x2266;Cu&#x2266;0.25%, or Cu&#x2266;0.5 Ni if Cu&#x3e;0.25%; traces&#x2266;Co&#x2266;1%; traces&#x2266;W&#x2266;0.2%; traces&#x2266;Nb&#x2266;0.15%; traces&#x2266;AI&#x2266;0.025%; traces&#x2266;Ti&#x2266;0.010%; traces&#x2266;S&#x2266;0.030%; traces&#x2266;P&#x2266;0.040%; traces&#x2266;B&#x2266;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&#xb0; C.; optionally soft annealing, between 650 and 900&#xb0; 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 said method.

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

Steel, characterized in that the composition thereof is, in percentages by weight: Method of producing a component from this steel and a component obtained in this manner.

Hardened martensitic steel having a low or zero content of cobalt, method for producing a component from this steel, and component obtained in this manner

The invention relates to steel which is characterized by the following composition as expressed in percentages by weight: &#x2014;C=0.18 0.30%, &#x2014;Co=5-7%, &#x2014;Cr=2-5%, &#x2014;Al=1-2%, &#x2014;Mo+W/2=1-4%, &#x2014;V=trace 0.3%, &#x2014;Nb=trace 0.1%, &#x2014;B=trace&#x2212;50 ppm, &#x2014;Ni=10.5-15% with Ni&#x2267;7+3.5 Al, &#x2014;Si=trace 0.4%, &#x2014;Mn=trace 0.4%, &#x2014;Ca=trace&#x2212;500 ppm, &#x2014;Rare earths=trace&#x2212;500 ppm, &#x2014;Ti=trace&#x2212;500 ppm, &#x2014;O=trace&#x2212;200 ppm if the steel is obtained by means of powder metallurgy or trace&#x2212;50 ppm if the steel is produced in air or under a vacuum from molten metal, &#x2014;N=trace&#x2212;100 ppm, &#x2014;S=trace&#x2212;50 ppm, &#x2014;Cu=trace&#x2212;1%, and &#x2014;P=trace&#x2212;200 ppm, the remainder including iron and the inevitable impurities resulting from production. The invention also relates to a method of producing a part from said steel and to the part thus obtained.

Hardened martensitic steel, method for producing a component from this steel and component obtained in this manner

The invention relates to steel which is characterized by the following composition as expressed in percentages by weight: &#x2014;C=0.18 0.30%, &#x2014;Co=5-7%, &#x2014;Cr=2-5%, &#x2014;Al=1-2%, &#x2014;Mo+W/2=1-4%, &#x2014;V=trace 0.3%, &#x2014;Nb=trace 0.1%, &#x2014;B=trace&#x2014;50 ppm, &#x2014;Ni=10.5-15% with Ni&#x2267;7+3.5 Al, &#x2014;Si=trace 0.4%, &#x2014;Mn=trace 0.4%, &#x2014;Ca=trace&#x2014;500 ppm, &#x2014;Rare earths=trace&#x2014;500 ppm, &#x2014;Ti=trace&#x2014;500 ppm, &#x2014;O=Trace&#x2014;200 ppm if the steel is obtained by means of powder metallurgy or trace&#x2014;50 ppm if the steel is produced in air or under a vacuum from molten metal, &#x2014;N=trace&#x2014;100 ppm, &#x2014;S=trace&#x2014;50 ppm, &#x2014;Cu=trace&#x2014;1%, and &#x2014;P=trace&#x2014;200 ppm, the remainder including iron and the inevitable impurities resulting from production. The invention also relates to a method of producing a part from said steel and to the part thus obtained.

The invention relates to steel which is characterized by the following composition as expressed in percentages by weight:&#x2014;C=0.18 0.30%, &#x2014;Co=5-7%, &#x2014;Cr=2-5%, &#x2014;Al=1-2%, &#x2014;Mo+W/2=1-4%, &#x2014;V=trace 0.3%, &#x2014;Nb=trace 0.1%, &#x2014;B=trace&#x2212;50 ppm, &#x2014;Ni=10.5-15% with Ni&#x2267;7+3.5 Al, &#x2014;Si=trace 0.4%, &#x2014;Mn=trace 0.4%, &#x2014;Ca=trace&#x2212;500 ppm, &#x2014;Rare earths=trace&#x2212;500 ppm, &#x2014;Ti=trace&#x2212;500 ppm, &#x2014;O=trace&#x2212;200 ppm if the steel is obtained by means of powder metallurgy or trace&#x2212;50 ppm if the steel is produced in air or under a vacuum from molten metal, &#x2014;N=trace&#x2212;100 ppm, &#x2014;S=trace&#x2212;50 ppm, &#x2014;Cu=trace&#x2212;1%, and &#x2014;P=trace&#x2212;200 ppm, the remainder comprising iron and the inevitable impurities resulting from production. The invention also relates to a method of producing a part from said steel and to the part thus obtained.

The invention concerns martensitic stainless steel, characterized in that its composition in weight percentages is as follows: 9%=Cr=13%; 1.5%=Mo=3%; 8%=Ni=14%; 1%=Al=2%; 0.5%=Ti=1.5% with AI+Ti=2.25%; traces=Co=2%; traces=W=1% with Mo+(W/2)=3%; traces=P=0.02%; traces=S=0.0050%; traces=N=0.0060%; traces=C=0.025%; traces=Cu=0.5%; traces=Mn=3%; traces=Si=0.25%; traces=O=0.0050%; and is such that: Ms (&#xb0; C.)=1302 42 Cr 63 Ni 30 Mo+20AI-15W-33Mn-28Si-30Cu-13Co+10 Ti=50Cr eq/Ni eq=1.05 with Cr eq (%)=Cr+2Si+Mo+1.5 Ti+5.5 AI+0.6W Ni eq (%)=2Ni+0.5 Mn+3O C+25 N+Co+0.3 Cu. The invention also concerns a method for making a mechanical part using said steel, and the resulting part.

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Rambouillet, France

Jacques Montagnon