Usinor

Industeel Creusot

Industeel France

Dominique Viale

Jean Beguinot

Marc Burty

François Stouvenot

Pascal Gardin

Jean-François Domgin

Raymond Reitz

Frédéric Leclercq

Method for reducing the segregated seams of a steel which has high mechanical strength and high wear resistance and whose composition comprises by weight: 0.30%&#x2266;C&#x2266;1.42%; 0.05%&#x2266;Si&#x2266;1.5%; Mn&#x2266;1.95%; Ni&#x2266;2.9%; 1.1%&#x2266;Cr&#x2266;7.9%; 0.61%&#x2266;Mo&#x2266;4.4%; optionally V&#x2266;1.45%, Nb&#x2266;1.45%, Ta&#x2266;1.45% and V+Nb/2+Ta/4&#x2266;1.45%; less than 0.1% of boron, less than 0.19% of (S+Se/2+Te/4), less than 0.01% of calcium, less than 0.5% of rare earths, less than 1% of aluminum, less than 1% of copper; the balance being iron and impurities resulting from the production operation. The composition further complies with: 800&#x2266;D&#x2266;1150 with D=540(C)+245(Mo+3V+1.5Nb+0.75Ta)+125Cr+15.8Mn+7.4Ni+18Si. According to the method, the molybdenum is completely or partially replaced with double the proportion of tungsten so that W&#x3e;0.21%, and Ti, Zr, C are adjusted so that, after adjustment, Ti+Zr/2&#x2267;0.2W, (Ti+Zr/2)&#xd7;C&#x2267;0.07, Ti+Zr/2&#x2266;1.49% and D is unchanged at approximately 5%. Steel obtained and method for producing a steel workpiece.

Steel having high mechanical strength and wear resistance

Method for reducing the segregated seams of a steel which has high mechanical strength and high wear resistance and whose composition comprises by weight: 0.30%&#x2266;C&#x2266;1.42%; 0.05%&#x2266;Si&#x2266;1.5%; Mn&#x2266;1.95%; Ni&#x2266;2.9%; 1.1%&#x2266;Cr&#x2266;7.9%; 0.61%&#x2266;Mo&#x2266;4.4%; optionally V&#x2266;1.45%, Nb&#x2266;1.45%, Ta&#x2266;1.45% and V+Nb/2+Ta/4&#x2266;1.45% ; less than 0.1% of boron, less than 0.19% of (S+Se/2+Te/4), less than 0.01% of calcium, less than 0.5% of rare earths, less than 1% of aluminum, less than 1% of copper; the balance being iron and impurities resulting from the production operation. The composition further complies with: 800&#x2266;D&#x2266;1150 with D=540(C)+245 (Mo+3 V+1.5 Nb+0.75 Ta)+125 Cr+15.8 Mn+7.4 Ni+18 Si. According to the method, the molybdenum is completely or partially replaced with double the proportion of tungsten so that W&#x3e;0.21%, and Ti, Zr, C are adjusted so that, after adjustment, Ti+Zr/2&#x2267;0.2 W, (Ti+Zr/2)&#xd7;C&#x2267;0.07, Ti+Zr/2&#x2266;1.49% and D is unchanged at approximately 5%. Steel obtained and method for producing a steel workpiece.

The invention relates to a tool steel, the composition of which comprises (the percentages being expressed in % by weight): the balance of the composition consisting of iron and impurities resulting from the smelting, it being furthermore understood that: 2.5&#xd7;10%&#x2266;(Ti+&#xbd;Zr)&#xd7;N, to a process for manufacturing parts made in this steel and to the parts obtained.

Reinforced durable steel, method for the production thereof, method for producing parts made of steel, and parts thus obtained

A vacuum treatment of cast metal in liquid form employing the steps of: introducing the cast metal in liquid form into a metallurgic ladle; filling the ladle until a guard height ranging between 0.4 and 0.6 m is reached; and treating the metal while bringing the atmosphere above the ladle under vacuum, and simultaneously stirring the cast metal by injecting helium into the base of the ladle during part of or the whole treatment.

Growing community of inventors

Marmagne, France

Dominique Viale