Wire for refining molten metal

Abstract

A smelting wire (11) comprising a metal sheath (12) enclosing a core (14) containing a refining material (14), the refining material (14) comprising calcium carbide, the calcium carbide being located at or near the center of the core along at least a portion of the length of the core.

Description

[Technical Field]

[0001] The present invention relates to a wire for refining a molten metal with additives, such as metallic materials and / or minerals, and to an associated method for producing such a wire.

[0002] Prior to casting a molten metal, such as molten steel, a refining wire can be injected into a vessel holding the molten metal, such as a ladle, pot, or continuous casting tundish, to improve and / or modify the metal's properties. The purpose of the refining wire is to introduce refinement materials, such as metals and / or minerals, enclosed in the wire sheath and alloying additives into the molten metal in precise amounts and in a controlled manner. This is often contemplated when the refining material exhibits a higher affinity for oxygen, a lower melting point and / or vapor point, a higher vapor pressure, a lower solubility or density, or a combination of these factors, compared to the molten metal. In this regard, it is important to achieve a high recovery rate of the refining or alloying material. This recovery rate is defined as the ratio of the amount of injected material remaining in the molten metal divided by the total amount of injected material. In addition to recovery, the overall performance measures of the refining wire also take into account the repeatability of recovery, inclusion treatment taking into account inclusion composition (shape, size, and quantity), homogeneity of the molten steel throughout the ladle, overall processing time, the amount and nature of fume emissions, reactions that occur during introduction of the refining wire that can cause "splash" and increase the freeboard height (and therefore decrease the amount of steel per ladle), and the shelf life of the refining wire.

[0003] In a known method for producing refined wire, a steel strip is rolled to form a U-shaped section, which is filled with the refined material in powder form. Two longitudinal edges of this U-shaped strip section (pre-folded) are then crossed over each other. In this way, a refined wire is formed, with a steel sheath enclosing a core of refined material.

[0004] Another method of producing refined wire is the same as above, except that the refined material is introduced into the U-shaped section as a solid extruded wire.

[0005] Due to manufacturing and product constraints, refined wire produced by these known methods typically has a sheath thickness in the range of 0.2 mm to 0.6 mm. As a result, the wire is easily deformed by the high pressure of the feeder pinch rolls used to inject the wire through the guide tube into the molten metal vessel, which may require guide tubes with relatively large inner diameters, which may hinder accurate guiding of the refined wire into the vessel, or the guide tubes may need to be located close to the surface of the molten metal, which adds further complexity and may require ceramic linings and shielding from the molten metal.

[0006] Furthermore, the refining wire may not have sufficient rigidity and may not be able to penetrate the solidified surface of slag floating on the surface of molten metal such as molten steel in a vessel.

[0007] Furthermore, the hook-type closures for the steel sheath of the refined wires described above do not allow such wires to be deeply rolled or drawn to much smaller diameters, in which case the core may contain excessive and undesirable amounts of air that adversely affect the quality of the molten metal and the recovery of the core material during the refining process. Moreover, the refined material may interact with the components of the air, thus reducing the shelf life of the wire.

[0008] Some of these drawbacks are due in part to the fact that the steel sheath of the refining wire is too thin, and secondly to the fact that the enclosed refining material is not sealed fluid-tight within the sheath.

[0009] In our previous patent application published as WO2006 / 079832, we proposed a solution to the drawbacks faced by prior art wire refining, in which we proposed a refined wire with a sheath thickness greater than 0.6 mm and a core of refining material with a density of 95% or more of theoretical.

[0010] In the above-identified patent applications, the inventors disclose the use of calcium, aluminum, or nickel, or combinations thereof, or calcium-silicon alloys, ferro-titanium alloys, ferro-boron alloys, or combinations thereof, as the refining material. The preferred refining material is powdered calcium. Silicon may also be added to the refining material. In some refining wires, the inventors use a mixture of silicon powder and calcium powder.

[0011] While our refining wire is well suited to allowing the addition of refining material to molten metal held in a vessel (even when there is a slag layer on the surface of the melt), it can be difficult to contain the reactivity of calcium (or other refining material) when it is submerged below the surface of the melt. The refining wire can become reactive or interact with the surface of the molten metal (e.g., violent reactions or interactions known as "splash") and / or result in less than optimal recovery, as well as creating a suboptimal performance situation involving oxygen entrapment and a potentially unsafe working environment.

[0012] In our patent application published as CN106834601, we propose a solution to the drawbacks faced by known wire refining methods. In that application, we propose a refining wire that includes a metal sheath that encapsulates a core containing the refining material and ferrous metal. It has been shown that the inclusion of ferrous metal in the core inhibits the activity of the refining material.

[0013] The smelting material may not only react with components of the air, but may also interact with other materials such as moisture or oxidizing agents, reducing the shelf life of the wire.

[0014] It is an object of the present invention to provide a refined wire that overcomes, or at least substantially reduces, the disadvantages associated with known refined wires discussed above, while allowing for the use of new or different refined materials.

[0015] Therefore, it may be desirable to use scouring materials that are less stable than those described above. For example, certain desirable scouring materials may react with air or moisture (and moisture in air), which has limited or entirely prevented their use in known scouring materials.

[0016] A first aspect of the present invention provides a molten metal refining wire comprising a metal sheath enclosing a core comprising a refining material, the core being fluid-tight sealed within the sheath, the refining material comprising a refining material that readily reacts in the presence of heat, moisture, air and / or other atmospheric agents.

[0017] Correspondingly, another aspect of the present invention provides a smelting wire comprising a metal sheath enclosing a core comprising a refining material, the core being fluid-tight sealed within the sheath, the refining material comprising pure calcium carbide or a combination of calcium carbide and other refining materials, the calcium carbide comprising at least 10 wt% of the refining material and / or at least 10 wt% of the core.

[0018] A further aspect of the present invention provides a smelting wire comprising a metal sheath enclosing a core comprising a refining material, the refining material comprising calcium carbide, the calcium carbide being located at or near the center of the core along at least a portion of the length of the core.

[0019] Preferably, calcium carbide is at least at the center of the core (or at least near the center), making the calcium carbide (or at least a portion thereof) less likely to react with moisture or other atmospheric constituents. For example, the calcium carbide may be radially surrounded within the wire by another element and / or longitudinally bounded by another element.

[0020] The calcium carbide may extend along a majority of the length of the core, for example, greater than 55%, greater than 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%. The calcium carbide may extend along the entire length of the core.

[0021] Calcium carbide has been proposed for use as a deoxidizer in ladles and in the production of low carbon steels (e.g., Metallurgist 48, 557-561 (2004)), but not as a constituent of refining wire.

[0022] Calcium carbide (also known as calcium acetylenide) is known to undergo a violent, high-temperature, exothermic hydrolysis reaction with even traces of water or moisture to form calcium oxide and the highly flammable gas acetylene (Equation 1). Furthermore, if the amount of water is insufficient, the resulting acetylene can spontaneously ignite. CaC2(s)+2H2O(l)→C2H2(g)+Ca(OH)2(s) (Formula 1)

[0023] The inventors understand that calcium carbide has not previously been used as a refining material in refining wire because such refining wire typically has a long shelf life and may remain in stock within a mill or foundry for a period of time before use. As such, the chemical properties of calcium carbide limit its use in refining wire. Because the product degrades in traditional wire form, depending on the tightness of the seal and the storage period and conditions, it may no longer provide an effective treatment reagent and / or may provide unreliable treatment performance.

[0024] Additionally, its use is avoided on the basis that the ingress of air and / or moisture into refined wire containing calcium carbide will cause rapid deterioration of the product or, more dangerously, the production of acetylene in the steel mill or foundry. For safety reasons alone, the use of calcium carbide in conventional wire would be unacceptable.

[0025] The refining material may comprise 10-100 w / w% of the core, for example, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95 w / w% of the core, up to 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100 w / w% of the core.

[0026] The core may comprise a mixture of materials, ie, in addition to calcium carbide, one or more additional materials may be present.

[0027] The one or more additional materials may include or be materials suitable for refining molten metal, e.g., molten steel, including, inter alia, pure calcium or silicon, aluminum or nickel metal, or any combination thereof, calcium-silicon alloy (CaSi), ferro-titanium alloy (FeTi), ferro-niobium alloy (FeNb), ferro-boron alloy (FeB), iron powder, or any combination thereof, e.g., mixed or separate calcium and silicon powder.

[0028] Additionally or alternatively, the one or more additional materials may include or be materials that do not participate in the refining of the molten metal, for example, molten steel.

[0029] The one or more additional materials may include carbon powder, iron powder, sulfur, lead, selenium, and vanadium.

[0030] Advantageously, for example, in accordance with our earlier patent application CN106834601, one or more additional materials may be present in the core to suppress the activity of the refining material, for example, to allow the refining material to penetrate further into the molten metal.

[0031] Thus, in embodiments, the core may comprise a non-alloyed ferrous metal, which may be iron, e.g., powdered iron. The one or more additional materials, e.g., powdered iron, may have a particle size of 0-1 mm (i.e., a number average particle size of 0-1 mm and / or preferably more than 50% of the particles fall within the particle size range of 0-1 mm).

[0032] One or more additional materials, e.g., iron powder, must be 4 kg / dm 3 Less than, for example, 4 kg / dm 3 Less than 3kg / dm 3 Less than 2kg / dm 3 less than, and preferably 1.5 kg / dm 3 In one embodiment, the one or more additional materials, such as iron powder, may have a bulk density of less than about 1.4 kg / dm 3 The one or more additional materials, e.g., iron powder, have a bulk density of (e.g., the theoretical density of iron, i.e., 7.86 g / cm 3 Although the bulk density may be relatively low (compared to theoretical), it is easily compressible when mixed with the smelting material. Thus, a mixture of the smelting material with one or more additional materials, such as iron powder, can be compressed to a high relative density (compared to theoretical) when using the methods of the prior art (e.g., WO 2006 / 079832).

[0033] Preferably, the one or more additional materials, for example iron powder, are substantially pure, meaning that they may have less than 5% impurities, preferably less than 4, 3, 2, 1%.

[0034] While the inventors do not wish or intend to be bound by any theory, they believe that the inclusion of an inhibitor(s), such as iron powder, has two distinct effects. First, the inhibitor acts as a diluent for the smelting material. This means that as the wire is submerged in the melt, less smelting material comes into contact per unit length, resulting in a gentler reaction / interaction between the melt and the core. Second, the additional material(s), such as iron, acts as a heat sink, again ensuring a smooth reaction. In this regard, the inventors also consider calcium carbide to be an inhibitor, and indeed can be added as such to smelting wire containing pure Ca metal (or other smelting material).

[0035] The one or more additional materials may comprise from 0 to 90 w / w% of the core, for example, from 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, or 85 w / w% of the core, up to 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 w / w% of the core.

[0036] Although the amount of refined material may be reduced by the use of one or more inhibitors, such as ferrous metal, the present inventors believe that the presence of additional material(s), such as iron, improves the overall recovery of refined material.

[0037] The smelting material may contain 10-100 w / w% calcium carbide, i.e. the smelting material contains 90-0 w / w% of one or more of the additional materials listed above.

[0038] For example, the smelting material may contain from 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95 w / w% calcium carbide up to 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100 w / w% calcium (and / or other known additional smelting agents).

[0039] For example, the refined material may include from 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, or 85 w / w% of one or more additional materials to 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 w / w% of one or more additional materials.

[0040] The one or more additional materials may be mixed with the calcium carbide before the calcium carbide is introduced into the sheath. The encapsulated core of refined material may include a mixture of calcium carbide and one or more additional materials. The mixture may be a homogeneous, or at least substantially homogeneous, mixture.

[0041] For example, the core may comprise calcium carbide, one or more additional refining materials, and one or more additional inhibitors, e.g., the core may comprise 10-90 w / w% calcium carbide, 10-90 w / w% calcium or calcium / silicon (and / or another additional refining material), and 10-90 w / w% iron powder (and / or another additional inhibitor), totalling 100 w / w% of the core.

[0042] The refined wire typically has a first end and a second end.

[0043] The refining wire preferably includes protective means or protection, for example, to at least partially inhibit, e.g., inhibit, reaction of calcium carbide with air, moisture, or other atmospheric agents, or to otherwise limit the reduction of available calcium carbide.

[0044] Safeguards or protection can take many forms.

[0045] In one embodiment, at least one of the first and second ends of the refining wire may be closed. At least one of the first and second ends may be welded, crimped, or sealed to at least partially close at least one of the first and second ends to prevent contact of the calcium carbide with air, moisture, or other atmospheric agents. The above-mentioned protection or protective means may be applied to the ends of the refining wire, for example, a coating or sealant may be applied to the free end. Multiple protections or multiple protective means may be applied to the refining wire.

[0046] Additionally or alternatively, the calcium carbide may be located near the longitudinal center of the refined wire and may be absent from one or both of the first and second ends. For example, the one or more additional materials may be located at at least one of the first and second ends to at least partially prevent contact of the calcium carbide with air, moisture, or other atmospheric agents.

[0047] Additionally or alternatively, the calcium carbide may be surrounded by one or more of the additional materials described above, i.e., the core may include an elongated central region comprising calcium carbide bounded radially or circumferentially by one or more of the additional materials described above.

[0048] Advantageously, the protective means or protection can stop, reduce or prevent reaction with air or other materials, such as moisture or oxidizers, for example, by forming a barrier between the smelting material (e.g., calcium carbide and / or one or more additional smelting materials) and air or other materials, such as moisture or oxidizers. For example, one or more additional materials, such as non-smelting materials or inhibitors, can form a fluid-tight barrier or seal between the smelting material, e.g., calcium carbide and / or one or more additional smelting materials, and the air or other materials.

[0049] Advantageously, the provision of protection or means of protection will increase the shelf life of the refined wire and will also seek to ensure optimal delivery of calcium carbide to the molten metal.

[0050] And surprisingly, refined wire can be produced economically without compromising performance.

[0051] The additional material(s), such as a refining material, a non-refining material, or an inhibitor (e.g., ferrous metal), may be mixed with the calcium carbide before the calcium carbide is introduced into the sheath. The mixture so formed may be a homogeneous mixture, or at least a substantially homogeneous mixture.

[0052] The metal sheath may be formed from a metal strip, the longitudinal edges of which may be sealed together to enclose the refining material, e.g., calcium carbide, and / or one or more additional materials.

[0053] The sheath may be made of any suitable metallic material, but if the refining wire is to be used to refining molten steel, the sheath is preferably a low carbon, low silicon steel, but may also be any suitable grade of metal that can be welded by the above method.

[0054] The sheath thickness can be up to 2.0 mm, for example, 0.6 to 2.0 mm, or 0.6 to 1.5 mm, for example, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, or 1.5 mm. The sheath thickness can be greater than 1.0 mm, for example, greater than 1.0 to 2.0 mm, for example, greater than 1.0 mm to 1.5 mm.

[0055] The wire may have an outer diameter of 5 to 20 mm, or 9 to 15 mm, or 10 to 14 mm.

[0056] Advantageously, wires with an outer diameter of 10 to 14 mm (with a sheath thickness of 0.6 to 2 mm, preferably 0.6 to 1.5 mm) are particularly useful in terms of the balance between cost, strength, and material loading.

[0057] The edges of the sheath may be welded, for example butt welded, to one another and both longitudinal edges may be sealed to one another in a fluid-tight manner.

[0058] Where the edges of the sheath are welded together, it may be appropriate, as a protective measure or protection, to at least partially surround the calcium carbide with one or more of the additional materials described above to at least partially protect it from the heat of the welding operation.

[0059] The one or more additional materials and calcium carbonate may be staggered along the length of the refined wire. For example, the one or more additional materials may be located in a first zone and a third zone, and calcium carbonate may be located in a second zone located between the first and third zones (or vice versa). The first, second, and third zones define at least a portion of the core and are spaced longitudinally along the wire.

[0060] Furthermore, the first zone and the third zone may contain a majority of the one or more additional materials (e.g., 51 to 99 w / w%, for example, 90 to 99 w / w%) and a minor amount of calcium carbide (e.g., 1 to 49 w / w%, for example, 1 to 10 w / w%). On the other hand, the second zone may contain a majority of calcium carbide (e.g., 51 to 99 w / w%, for example, 90 to 99 w / w%) and a minor amount of the one or more additional materials (e.g., 1 to 49 w / w%, for example, 1 to 10 w / w%).

[0061] The zone (or zones) containing calcium carbide may comprise a major longitudinal proportion of the core, while the zone (or zones) not containing calcium carbide (or containing a small amount of calcium carbide) may comprise a very small longitudinal proportion of the core.

[0062] Preferably, the ends of the wire correspond to a part of the core that is free of calcium carbide (0 w / w%) or contains only small amounts (<50 w / w%, preferably less than 40, 30, 20, 10, 5 w / w%).

[0063] The metal sheath may include one or more marks or indicators on the outer surface of the refined wire to indicate the actual or approximate location of the calcium carbide and / or one or more additional materials.

[0064] Another aspect of the present invention provides a molten metal refining wire having a first end and a second end and including a metal sheath enclosing a core including a refining material, the core being fluid-tight sealed within the sheath, the metal sheath having an outer surface including one or more marks or indicators between the first end and the second end, the marks or indicators indicating the range of at least one component of the refining material.

[0065] For example, if the refining wire includes a length and the additional material is located at at least one of the first and second ends and at a location between the first and second ends, the metal sheath may include a mark or indicator indicating the endpoint of the additional material at at least one of the first and second ends and another mark or indicator indicating the location of the additional material at a location between the first and second ends. In this way, an operator is provided with a visual guide to recognize the limits of the calcium carbide range and can easily expose the calcium carbide at the end of the refining wire or cut the refining wire at the location of the additional material so as not to expose the calcium carbide to air, moisture, or other atmospheric agents.

[0066] A second aspect of the invention is a method of manufacturing a smelting wire comprising a metal sheath enclosing a core comprising a refining material, the core being fluid-tight sealed within the sheath, the refining material comprising calcium carbide.

[0067] A third aspect of the present invention resides in a method of manufacturing a smelted metal refined wire comprising a metal sheath enclosing a core comprising a refinement material, the method comprising forming a metal strip within the sheath, with the refinement material comprising calcium carbide enclosed within the sheath, and sealing the longitudinal edges of the sheath so formed to one another.

[0068] The method may include disposing calcium carbide on a metal strip and forming a sheath, wherein one or more of disposing the calcium carbide and / or forming the sheath is carried out under an inert atmosphere, for example under vacuum, or preferably using an inert and / or dry gas such as argon and / or nitrogen.

[0069] A fourth aspect of the invention comprises the use of a refining wire in refining steel or molten steel, the refining wire comprising a metal sheath enclosing a core comprising a refining material comprising calcium carbide, the use comprising providing calcium carbonate to an exposed end of the refining wire.

[0070] This use may involve feeding the exposed end of the refining wire into the melt of molten metal.

[0071] In the above method or use, the core may comprise one or more of any of the additional materials set out above in relation to the first embodiment.

[0072] The method may include, for example, providing a safeguard or protection to at least partially inhibit, e.g., inhibit, reaction of calcium carbide with air, moisture, or other atmospheric agents, or to otherwise limit the reduction of available calcium carbide.

[0073] In one embodiment, the method can include closing at least one of the first end and the second end, which can be welded, crimped, or sealed to at least partially close each of the first end and the second end to at least partially prevent contact of the calcium carbide with air, moisture, or other atmospheric agents.

[0074] Additionally or alternatively, the method may include disposing calcium carbide near the longitudinal center of the refined wire, but not disposing calcium carbide at one or both of the first and second ends. For example, the one or more additional materials may be located at at least one of the first and second ends to at least partially prevent contact of the calcium carbide with air, moisture, or other atmospheric agents.

[0075] Additionally or alternatively, the method may include surrounding the calcium carbide with one or more additional materials as described above, i.e., the core may include an elongated central region comprising calcium carbide that is radially or circumferentially bounded at least partially (and preferably entirely) by one or more additional materials as described above.

[0076] Advantageously, the protective means or protection can stop, reduce or prevent reaction with air or other materials, such as moisture or oxidizers, for example, by forming a barrier between the smelting material (e.g., calcium carbide and / or one or more additional smelting materials) and air or other materials, such as moisture or oxidizers. For example, one or more additional materials, such as non-smelting materials or inhibitors, can form a fluid-tight barrier or seal between the smelting material, e.g., calcium carbide and / or one or more additional smelting materials, and the air or other materials.

[0077] For example, calcium carbide may be located near the center of the wire, and suppressor (and / or less reactive or non-reactive refining material) may be located near (or at) the ends of the refining wire. Additionally, the calcium carbide may be radially bounded by additional material (e.g., refining material and / or suppressor).

[0078] In a preferred embodiment, the calcium carbide is disposed at least along the central longitudinal axis of the core along at least a portion of the length of the core, and therefore, that portion of the core contains the highest amount (w / w) of calcium carbide.

[0079] The protection or protective means described above may be (and is usually) applied to the end of the refined wire, for example a coating or sealant may be applied to the free end. Multiple protections or multiple protective means may be applied to the refined wire.

[0080] In any aspect of the method or use defined in steam, the sheath may be made of any suitable metallic material, but where the refining wire is used to refining molten steel, the sheath may preferably be a low carbon, low silicon steel.

[0081] The edges of the sheath are preferably butt-welded together so that both longitudinal edges may be sealed together in a fluid-tight manner.

[0082] To reduce the amount of oxygen, air, or other harmful gases remaining in the sheath of the wire so formed, the wire can be deeply rolled or drawn to a smaller diameter, thereby allowing such gases to escape from the wire without compromising the integrity of the wire, while at the same time helping to more tightly close the sheath around the core. In this way, the refined core material can achieve an apparent density ratio of more than 80% of the theoretical solid core equivalent.

[0083] A further aspect of the present invention provides a method of refining molten metal, the method comprising feeding, e.g. injecting, into the molten metal a refining wire according to an aspect of the present invention or a wire produced according to the further aspect of the present invention defined above.

[0084] The method may, for example, include exposing at least one end of the refining wire prior to injecting the refining wire into the molten metal, which may, for example, include cutting a portion of the refining wire to expose the refining material.

[0085] A further aspect of the invention provides a method of storing and / or transporting calcium carbide, the method comprising: placing calcium carbide, which may be in powder or granular form, on an elongated length of metal having a first elongated side and a second elongated side; and bringing the first elongated side and the second elongated side together to form a hollow structure, whereby the calcium carbide is disposed within the hollow structure and is at least partially protected from atmospheric reactants.

[0086] The first and second sides may be welded together, thereby forming a sealed tube. The calcium carbide may be located within the metal sheath in a non-reactive atmosphere, e.g., a dry, inert atmosphere, e.g., nitrogen or argon gas. The ends of the tube may include protection that at least partially prevents reaction of the calcium carbide with air, moisture, and / or other atmospheric agents. For example, the ends of the tube may be crimped or welded closed. Additionally or alternatively, the calcium carbide may be preferentially located near the center of the tube, with another species (i.e., a species less reactive to air, moisture, and / or other atmospheric agents than the calcium carbide) located near or at the ends of the tube.

[0087] While the above has focused primarily on refining wire containing calcium carbide, the use of the protection (or protection means) is not limited to the use of calcium carbide and can be used with other desired refining materials (or reactive species) that have not previously been used due to their reactivity. Thus, the above references to calcium carbide can be substituted with the desired refining material, e.g., having a relatively high reactivity, in the refining wire with the additional protection (or protection means).

[0088] In each of the above aspects, the core preferably does not include a solid metal central core, e.g., a solid metal calcium, iron, or other metal core. Furthermore, the wire preferably provides the core with a single central compartment rather than multiple zones subdivided by concentric tubes. The sheath preferably is in the form of a single metal layer. One or more of these features allows for maximum loading of core material while minimizing the amount of sheath material (regardless of the preferred sheath dimensions described above).

[0089] In order that the present invention may be more fully understood, refined wire in accordance with this specification will now be described, by way of example only, with reference to the accompanying examples and drawings. [Brief explanation of the drawings]

[0090] [Figure 1A] FIG. 1A is a cross-sectional view of a wire for refining molten steel, according to an embodiment of the present invention. [Figure 1B] FIG. 1B is a cross-sectional view of a wire for refining molten steel, according to an embodiment of the present invention. [Figure 2A] FIG. 2A shows a wire for refining molten steel according to the present invention. [Figure 2B] FIG. 2B shows a wire for refining molten steel according to the present invention. [Figure 2C] FIG. 2C shows a wire for refining molten steel according to the present invention. [Figure 3A]FIG. 3A is a schematic illustration of a further wire for refining molten steel according to a further embodiment of the present invention. [Figure 3B] FIG. 3B is a schematic illustration of a further wire for refining molten steel according to a further embodiment of the present invention. [Figure 4A] FIG. 4A is a schematic illustration of yet a further wire for refining molten steel, in accordance with a further embodiment of the present invention. [Figure 4B] FIG. 4B is a schematic illustration of yet a further wire for refining molten steel, in accordance with a further embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0091] Referring initially to a refined wire generally designated 1 in Figure 1A, the wire may include a steel sheath 2 formed from a strip of steel with each longitudinal edge bent into the shape of a hook 3. The steel sheath is formed from the strip of steel bent into a U-shape to receive therein a powdered refined material 4, the refined material 4 including calcium carbide. The two pre-folded edges 3 are then crossed together, enclosing the refined material 4 within the sheath 2 as a core.

[0092] The refining material 4 may comprise a mixture of materials, i.e., the refining material 4 may comprise one or more additional materials in addition to calcium carbide. The one or more additional materials may include or be a material suitable for refining a molten metal, such as molten steel, including, inter alia, pure calcium or silicon, aluminum or nickel metal, or any combination thereof, calcium-silicon alloy (CaSi), ferro-titanium alloy (FeTi), ferro-niobium alloy (FeNb), ferro-boron alloy (FeB), iron powder, or any combination thereof, which may be mixed or separate, such as calcium and silicon powder. In one embodiment, the one or more additional materials may be selected from nickel, calcium, silicon, or calcium-silicon alloy (CaSi), ferro-titanium alloy (FeTi), ferro-niobium alloy (FeNb), ferro-boron alloy (FeB), or combinations thereof.

[0093] Referring to FIG. 1B, refined wire 1′ of FIG. 1B is the same as refined wire 1 of FIG. 1A, except that refined material 4′ includes calcium carbide, and the calcium carbide is surrounded by one or more additional materials 5′, which may be, for example, one or more refining materials or inhibiting materials.

[0094] The one or more additional materials 5' may be or provide a protective means or protection, for example, to at least partially inhibit, e.g., inhibit, reaction of calcium carbide with air, moisture, or other atmospheric agents, or to otherwise limit reduction of available calcium carbide.

[0095] 2A, there is shown a schematic diagram of a refined wire 11 according to the present invention, in which a steel sheath 12 is formed from a strip of steel initially formed into a generally U-shape, which is supplied with a core refined material 14 comprising calcium carbide. Typically, the calcium carbide is located on the strip of metal under an inert atmosphere, for example an atmosphere provided by a blanket of an inert gas such as argon or nitrogen.

[0096] The refining material 14 may include a mixture of materials, i.e., the refining material 14 may include one or more additional materials in addition to calcium carbide. The one or more additional materials may include or be materials suitable for refining molten metal, such as molten steel, including, among others, additional refining materials such as pure calcium or silicon, aluminum or nickel metal, or any combination thereof, calcium-silicon alloy (CaSi), ferro-titanium alloy (FeTi), ferro-niobium alloy (FeNb), ferro-boron alloy (FeB), and / or additional inhibitors such as iron powder, or any combination thereof, whether mixed or separate, such as calcium and silicon powder and iron powder.

[0097] 1A and 1B, the facing or abutting longitudinal edges 15 of the sheath 12 are fluidly sealed to one another by welding (see FIG. 2B, which shows a cross section of the wire 11 along line AA in FIG. 2A). The weld seam 13 thus formed therefore encapsulates in a sealed, fluid-tight manner the refining material 14 in the core of the wire 11 within the sheath 12, thereby reducing, and preferably preventing, the ingress of undesirable oxygen or other gases or materials into the interior of the sheath 12 during the molten metal refining process.

[0098] Also, when the wire 11 is deep rolled or drawn to reduce its diameter, the air, oxygen, or other gases present within the sheath 12 are reduced by being expelled from the sheath interior. This also helps to close the sheath 12 more tightly around the refining material 14 within the core.

[0099] 1B, the calcium carbide-containing refining material 14 may be surrounded by one or more additional materials, which may be, for example, one or more additional refining materials and / or inhibitor materials. In this embodiment, such protection may help limit exposure of the calcium carbide to atmospheric agents and / or any heat generated in the butt welding process.

[0100] Referring to FIG. 2C, this embodiment differs from the embodiment of FIG. 2A in that at least one, and preferably both, of the first end 11 a and the second end 11 b of the wire 11 are closed, i.e., welded, crimped, or sealed, so that at least one of each of the first end 11 a and the second end 11 b is at least partially occluded, thereby at least partially preventing contact of the purified material 14 comprising calcium carbide with air, moisture, or other atmospheric agents.

[0101] Referring now to Figure 3A, there is shown a schematic diagram of a further refined wire 11'. Wire 11' is similar to wire 11 of Figures 2A-2C. Like features are indicated with like reference numerals except for the following prime and will not be described further.

[0102] 2A-2C in that the wire 11' includes additional materials 16a', 16b' located on at least one, but preferably both, of the ends (11a', 11b') of the refined wire 11'. The additional materials 16a', 16b' can be refined materials, non-refined materials, or inhibitors (but do not include calcium carbide).

[0103] Advantageously, for example, in accordance with the inventors' previous patent application CN106834601, one or more of the additional materials 16a', 16b' may be present in the core to suppress the activity of the refining material 14', for example, to allow the refining material 14' to penetrate further into the molten metal.

[0104] The additional materials 16a', 16b' may be the same as one another or may be different.

[0105] In this embodiment, the refining material 14' is located near the longitudinal center of the wire 11', and the additional materials 16a', 16b' are located at the first end 11a' and the second end 11b' of the wire 11' (where the dashed line represents the boundary between the refining material 14 and the additional materials 16a', 16b' (see FIG. 3A)). Advantageously, by placing the additional materials 16a', 16b' at the first end 11a' and the second end 11b' of the wire 11', reaction of the refining material 14', i.e., calcium carbide or a mixture of refined materials containing calcium carbide, with air or other materials, such as moisture or oxidizing agents, is stopped or at least reduced.

[0106] Advantageously, the provision of the additional materials 16a', 16b' further increases the shelf life of the wire 11' and seeks to ensure optimal delivery of the refining material 14', i.e., calcium carbide or a mixture of refining materials containing calcium carbide, to the molten metal.

[0107] 3B, the steel sheath 12' in this embodiment has markings 17a', 17b' that indicate the boundary between the refining material 14', i.e., calcium carbide or a mixture of refining materials including calcium carbide, and the additional materials 16a', 16b'. The markings 17a', 17b' in this embodiment are indentations in the sheath 12'. The markings 17a', 17b' may provide a convenient visual marker that allows an operator (or machine) to remove the additional materials 16a' or 16b' before use, if desired.

[0108] 4A and 4B, a further refined wire 11" is shown. The refined wire 11" is similar to the wire 11' of FIGS. 3A and 3B. Like features are designated with like reference numerals except for the following prime and will not be described further.

[0109] Wire 11" includes alternating sections of refined material 14" and additional components 16". In this embodiment, there are three segments of refined material 14a", 14b", and 14c". In this embodiment, there are four segments of additional components 16a", 16b", 16c", and 16d".

[0110] The smelting material 14" in each of sections 14a", 14b", and 14c" may be different or the same. The smelting material may comprise 100% calcium carbide or may comprise a mixture of calcium carbide and one or more additional components.

[0111] The additional components in each of sections 16a", 16b", 16c", and 16d" may be different or the same. It is understood that there may be fewer or more than shown.

[0112] In this embodiment, each section of refined material 14" is located between sections of additional component(s) 16".

[0113] Marks 17" indicate the location of refining material 14" and / or additional material 16". Marks 17" may be indentations in sheath 12" or marks applied to sheath 12".

[0114] As shown in FIG. 4A, marks 17a"-17f" indicate the boundary between refined material 14a"-14c", ie, calcium carbide or a mixture of refined materials containing calcium carbide, and additional material 16a"-16d".

[0115] As shown in FIG. 4B, mark 17a" indicates the boundary between refined material 14a" and additional material 16a", and mark 17d" indicates the boundary between refined material 14c" and additional material 16d". Meanwhile, marks 17b" and 17c" indicate the center points (not the boundaries / end points) of additional materials 16b" and 16c", respectively.

[0116] In this way, the worker is provided with a visual guide by which he can determine the extent of the refining material 14", i.e., calcium carbide or a mixture containing calcium carbide, and can easily expose the refining material 14", i.e., calcium carbide or a mixture containing calcium carbide, at the end of the refining wire 11", or cut the refining wire 11" at the location of the additional material 16", so that the calcium carbide is not exposed to, for example, air, moisture, or other atmospheric agents.

[0117] Additionally, the ends of the refined wire 11' or 11" may be welded or crimped as described in connection with the refined wire of Figure 2C.

[0118] Typically, depending on the operating conditions of the refining process, providing a smaller diameter wire requires deep rolling or drawing of the wire, which at the same time tends to close the sheath more tightly around the wire core.

[0119] It can therefore be seen that the present invention provides a refining wire that improves metal refining technology, particularly in terms of reducing impurities injected into the molten metal while maintaining its overall integrity during the process of feeding into the molten metal and penetrating the molten metal via the slag floating on the surface of the molten metal.

[0120] Additionally, because the sheath is sealed and has a uniform, continuous, and generally smooth outer periphery, it can be easily rolled or drawn to a smaller diameter without compromising the integrity of the sheath, while simultaneously allowing air, oxygen, or other undesirable gases to escape from within the sheath.

[0121] Additionally, the use of an inert atmosphere during manufacturing can help limit the loss of calcium carbide (or other reactive materials used). Providing various protective measures can increase shelf life or reactive materials.

[0122] Additionally, deep rolling or drawing of refined wire to smaller diameters can provide core materials that maintain apparent densities or compression ratios greater than 80% of their theoretical solid core equivalents.

[0123] Additionally, the techniques described herein facilitate the use of additional smelting materials, such as calcium carbide, which may be susceptible to reaction with atmospheric agents. Additionally, the disclosed methods allow for the safe storage and / or transportation of reactive materials such as calcium carbide.

Claims

1. A molten refining wire comprising a metal sheath enclosing a core containing a refining material, wherein the refining material contains calcium carbide, and the calcium carbide is located at or near the center of the core along at least a portion of the length of the core.

2. The wire according to claim 1, wherein the refining material is contained in 10 to 100 w / w% of the core.

3. The wire according to claim 1, wherein the refining material contains 10 to 100 w / w% calcium carbide.

4. The wire according to any one of claims 1 to 3, wherein the core or the refining material further comprises one or more additional materials.

5. The wire according to claim 4, wherein the one or more additional materials include materials suitable for refining molten metal.

6. The wire according to claim 5, wherein the one or more additional materials are selected from pure calcium or silicon, aluminum or nickel metal, or any combination thereof, calcium-silicon alloy (CaSi), ferro-titanium alloy (FeTi), ferroniob alloy (FeNb), ferro-boron alloy (FeB), or a combination thereof, for example, a mixture or separate calcium and silicon powders.

7. The wire according to claim 4, wherein the one or more additional materials include carbon powder, iron powder, sulfur, lead, selenium, and vanadium.

8. The wire according to claim 4, wherein the one or more additional materials or further materials are contained in 0 to 90 w / w% of the core.

9. The wire according to claim 4, wherein the calcium carbide extends longitudinally along the core and is surrounded by the one or more additional materials.

10. The wire according to claim 4, wherein the wire has a first end and a second end.

11. The wire according to claim 10, wherein the one or more additional materials are located at least one of the first end and the second end.

12. The wire according to claim 10, wherein at least one of the first end and the second end is closed, for example, by welding, crimping or sealing to at least partially close at least one of the first end and the second end.

13. The wire according to claim 4, wherein the calcium carbide and the one or more additional materials are arranged alternately along the length of the wire.

14. The wire according to any one of claims 1 to 3, wherein the thickness of the metal sheath is 0.6 to 2.0 mm, and / or the outer diameter of the wire is 5 to 20 mm, preferably 9 to 15 mm, most preferably 10 to 14 mm.

15. The wire according to any one of claims 1 to 3, wherein the wire has an outer surface and one or more indicators on the outer surface, the indicators indicating the extent of the calcium carbide in the core.

16. A method for producing a molten refining wire comprising a metal sheath enclosing a core of refining material, the method comprising fluid-tightly enclosing the core within the metal sheath, wherein the refining material comprises calcium carbide.

17. The method according to claim 16, comprising arranging the calcium carbide near the center of the refining wire.

18. The method according to claim 16, comprising closing at least one of the first and second ends of the refining wire, for example, crimping, welding, or sealing at least one of the first and second ends.

19. The method according to any one of claims 16 to 18, comprising sealing the core by welding the opposing edges of the metal sheath.

20. The method according to any one of claims 16 to 18, comprising placing the calcium carbide on the metal sheath and / or encapsulating the calcium carbide within the metal sheath in a non-reactive atmosphere.

21. The use of a refining wire in the refining of molten steel, wherein the refining wire comprises a metal sheath enclosing a core containing a refining material, and the refining material contains calcium carbide.

22. The use of the refining wire according to claim 21, comprising providing calcium carbide to the exposed end of the refining wire and feeding the exposed end of the refining wire into the molten metal.

23. The method according to any one of claims 16 to 18, comprising providing one or more additional materials, for example, pure calcium or silicon, aluminum or nickel metal, or any combination thereof, calcium-silicon alloy (CaSi), ferro-titanium alloy (FeTi), ferroniob alloy (FeNb), ferro-boron alloy (FeB), or a combination thereof, for example, mixed or separate calcium and silicon powders, carbon powder, iron powder, sulfur, lead, selenium, and vanadium.

24. The method according to claim 23, comprising surrounding the calcium carbide with one or more additional materials.

25. The method according to any one of claims 16 to 18, comprising exposing at least one end of the refining wire before injecting the refining wire into the molten metal.

26. The use according to claim 21, comprising providing one or more additional materials, for example, pure calcium or silicon, aluminum or nickel metal, or any combination thereof, calcium-silicon alloy (CaSi), ferro-titanium alloy (FeTi), ferroniob alloy (FeNb), ferro-boron alloy (FeB), or a combination thereof, for example, mixed or separate calcium and silicon powders, carbon powder, iron powder, sulfur, lead, selenium, and vanadium.

27. ​​The use according to claim 26, comprising surrounding the calcium carbide with one or more additional materials.

28. The use according to claim 21, comprising exposing at least one end of the refining wire before injecting the refining wire into the molten metal.

Images