Vallourec

Affival

Michel Douchy

Edmond Vachiery

Jean-Louis Tranchant

Michel Jehan

The method concerns the desulphurization of cast iron produced by a blast furnace, before it is converted to steel. In a first phase of the process the cast iron is treated with a desulphurizing compound such as Na.sub.2 CO.sub.3. A very long composite product with a tubular skin is then added to the cast iron. The product comprises an axial zone containing magnesium in powdered or granular form, and an annular zone, separated from the axial zone by an intermediate wall and containing a powdered or granular material. An inert gas could then be injected and a clearing operation carried out.

Method of desulphurizing pig-iron

The invention concerns a composite article with a tubular metal sheath containing a compacted powdery or granular material. The article is of substantially circular cross section (153). Its sheath comprises at least one closed fold (154), the fold edge (156) of which is within the compacted material. The article is produced by forming an open fold along a generatrix of a circular metal sheath containing a non-consolidated powdery or granular material and then constricting the sheath so as to close the fold. The article is used for the treatment of meal baths, for example for the treatment of steel in a ladle.

Composite article having a tubular sheath containing a compacted

The invention relates to a composite product of substantial length for the treatment of metal baths which is formed by a tubular metal casing (2) within which are housed the treatment material or materials in powder form and which comprises an axial zone (4) containing a first material surrounded by a tubular metal intermediate wall (3) and an annular zone (6) between the casing and the intermediate wall and which also contains a second material. Such a composite product in which the axial zone contains at least one element selected from calcium and magnesium can be used in particular for the desulphurization of iron or steel baths.

Composite product with a tubular casing for treating molten metal baths

The invention concerns a composite article with a tubular metal sheath containing a compacted powdery or granular material. The article is of substantially circular cross section (153). Its sheath comprises at least one closed fold (154), the fold edge (156) of which is within the compacted material. The article is produced by forming an open fold along a generatrix of a circular metal sheath containing a non-consolidated powdery or granular material and then constricting the sheath so as to close the fold. The article is used for the treatment of metal baths, for example for the treatment of steel in a ladle.

The invention concerns a composite product, also referred to as cored wire, comprising a tubular metal casing having a welt-type seam, containing a core of compacted powder or granular material, which can be easily rolled up and then unrolled, without the risk of the seam coming undone. The composite product according to the invention comprises, on the outside wall of the casing and straddling the seam region, hollow impressed portions which are produced by cold deformation of the metal. These portions are in the form of grooves which are elongate transversely with respect to the axis of the composite product. The composite product according to the invention is used, in particular, for treating metal baths.

Composite product having a tubular metal casing with a welt-type seam,

For the purpose of introducing an additive into a molten metal bath, a reactive powder is enclosed in a tubular sleeve composed of a metal compatible with the bath. The cross-section of the sleeve is reduced after filling to compact the powder while leaving it porous. The filled sleeve can be formed by profiling a metal strip to a cup-shaped cross-section, metering the powder into the cup-shaped profile, closing the edges of the strip together to enclose the powder, forming the edges to hook together and crimping the hooked edges.

Growing community of inventors

Solesmes, France

Michel Douchy