WO2021014452A1 - Reduced hexavalent chromium emission sts electrodes - Google Patents

Abstract

A composition comprising 25% to 45% (w/w) rutile, 4% to 45% (w/w) alkali metal silicates, and 5% to 50% (w/w) alkali metal carbonates, is provided. Further, articles comprising the composition are provided.

Description

REDUCED HEXA VALENT CHROMIUM EMISSION STS ELECTRODES

CROSS-REFERENCE TO RELATED APPLICATIONS

[001] This application claims the benefit of priority of U.S. Provisional Patent Application No. 62/878,165 filed July 24, 2019, entitled“Reduced Hexavalent Chromium Emission STS Electrodes”, the contents of which are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION [002] The present invention is in the field of welding electrodes.

BACKGROUND OF THE INVENTION

[003] Welding produces a number of hazards during operation, including physical agents such as extreme heat and ultraviolet radiation, as well as fumes and toxic gases. What is less well known is the composition of the fumes and the effects that welding conditions have on them. Among the elements that welding fumes contain, Cr (both hexavalent and total Cr) can be a significant portion of the fumes generated. Cr in the +6 oxidation state, Cr(VI), has been identified as a toxic air contaminant. Hexavalent chromium compounds are the most harmful substrates, which are emitted during welding of stainless steel and they are defined as carcinogen substances. There is a need for new welds with a low fume generation rate, especially low hexavalent chromium emission.

SUMMARY OF THE INVENTION

[004] According to one aspect, there is provided a composition comprising 25% to 45% (w/w) rutile, 4% to 45% (w/w) alkali metal silicates, and 5% to 50% (w/w) alkali metal carbonate. [005] In one embodiment, the alkali metal silicates comprise at least two silicates selected from sodium silicate, lithium silicate, potassium silicate, rubidium silicate, cesium silicate, francium silicate, or any combination thereof.

[006] In one embodiment, the alkali metal carbonate comprise calcium carbonate, barium carbonate, cesium carbonate, strontium carbonate, or any combination thereof.

[007] In one embodiment, the composition comprises 5% to 20% (w/w) low carbon ferro-alloy.

[008] In one embodiment, the low carbon ferro-alloy comprises low carbon ferro manganese, low carbon ferro-chromium, or both.

[009] In one embodiment, the composition comprises 5% to 50% (w/w) aluminum silicate.

[010] In one embodiment, the aluminum silicate comprise kyanite, silitin, calcinated kaolinite, petalite, spodumene, bentonite, china clay or any combination thereof.

[Oi l] In one embodiment, the composition comprises 1% to 8% (w/w) of titanium dioxide.

[012] In one embodiment, the composition comprises 1% to 7% (w/w) fluorspar.

[013] In one embodiment, the composition comprises 0.2% to 3% (w/w) of a slip agent.

[014] In one embodiment, the slip agent is selected from carboxymethylcellulose (CMC), hydroxyethyl cellulose, calcium alginate, guar gum, talc, clay, and any combination thereof.

[015] In one embodiment, the composition is in the form of a coating on a substrate.

[016] In one embodiment, the substrate comprises one or more metals.

[017] According to another aspect, there is provided an article comprising the composition of the present invention. [018] In one embodiment, the article comprises a metal wire and the composition being in the form of a coating on at least one surface of the article.

[019] In one embodiment, the article is a tubular welding wire.

[020] In one embodiment, the welding wire is characterized by a diameter of a core metal wire in the range of 1.6 mm to 6 mm.

[021] In one embodiment, the coating is in the form of a welding flux.

[022] In one embodiment, the article is a shielded arc welding electrode.

[023] In one embodiment, the shielded arc electrode is a welding consumable.

[024] In one embodiment, the article is characterized by weld metal ductility of 20% to 70% elongation as compared to the original material length.

[025] In one embodiment, the article is characterized by ultimate tensile strength (UTS) of 5 MPa to 1000 MPa.

[026] In one embodiment, the article is characterized by yield point of 400 MPa to 600 MPa.

[027] Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

[028] Further embodiments and the full scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[029] Figure 1 is a bar graph of the total fume emission rate of a standard electrode as reference and Electrode 1 ; and

[030] Figure 2 is a bar graph of the hexavalent chromium emission rate of a standard electrode as reference and Electrode 1.

DETAILED DESCRIPTION OF THE INVENTION

[031] According to some embodiments, the present invention provides a composition comprising rutile, alkali metal silicates, and alkali metal carbonates. In some embodiments, the present invention provides a composition comprising rutile, two or more alkali metal silicates. In some embodiments, the composition comprises a low sodium and potassium content. In some embodiments, the composition comprises strontium carbonate and barium carbonate. In some embodiments, the composition is in the form of a coating on a substrate. In some embodiments, the coating is a single uniform coating layer. In some embodiments, the coating is substantially homogenous.

[032] In some embodiments, the composition is substantially devoid of potassium feldspar. In some embodiments, the composition is devoid of sodium feldspar. As used herein, the phrases "potassium feldspar" and "sodium feldspar" refer to silicate minerals in which the silicate tetrahedral and aluminum tetrahedral are bound with potassium and sodium ions, correspondingly. In some embodiments, feldspar refers to aluminum phyllosilicate (Si2_xOs_x). In some embodiments, the composition is substantially devoid of lithium aluminosilicate. In some embodiments, the composition is substantially devoid of alkaline earth metal silicate. In some embodiments, the composition is substantially devoid of lithium carbonate. In some embodiments, the composition is substantially devoid of transition metal carbonate. In some embodiments, the composition is substantially devoid of zirconia.

[033] In some embodiments, the composition is substantially devoid of alginate (such as sodium alginate).

[034] In some embodiments, the composition comprises low manganese content. In some embodiments, the composition comprises low ferromanganese content. In some embodiments, the composition comprises nitrided ferrochromium. In some embodiments, the composition comprises nitrided chromium.

[035] According to some embodiments, the present invention provides an article comprising a composition described herein deposited on at least one surface of the article. In some embodiments, the article is an electrode. In some embodiments, the electrode comprises low sodium and potassium content, without causing any significant deterioration in its weldability properties.

[036] According to some embodiments, the electrode described herein is characterized by a reduction of the total fume emission rate during welding process when compared to the total fume emission rate of a standard electrode. According to some embodiments, the electrode described herein is characterized by a reduction of the rate emission of hexavalent chromium during welding process when compared to the rate emission of hexavalent chromium of a standard electrode. According to some embodiments, the electrode described herein is characterized by a reduction of the rate emission of manganese during welding process when compared to the rate emission of manganese of a standard electrode. The composition

[037] According to some embodiments, the present invention provides a composition comprising 30% to 45% (w/w) rutile, 4% to 45% (w/w) alkali metal silicates, and 5% to 50% (w/w) alkali metal carbonates.

[038] In some embodiments, the composition comprises 31% to 45% (w/w), 32% to 45%

(w/w), 33% to 45% (w/w), 35% to 45% (w/w), 36% to 45% (w/w), 38% to 45% (w/w), 40% to 45% (w/w), 42% to 45% (w/w), 31% to 40% (w/w), 32% to 40% (w/w), 33% to 40% (w/w), 35% to 40% (w/w), 36% to 40% (w/w), 38% to 40% (w/w), 31% to 43% (w/w), 32% to 43% (w/w), 33% to 43% (w/w), 35% to 43% (w/w), 36% to 43% (w/w), 38% to 43% (w/w), or 40% to 43% (w/w), rutile, including any range therebetween.

[039] In some embodiments, the composition comprises 5% to 45% (w/w), 8% to 45% (w/w), 10% to 45% (w/w), 12% to 45% (w/w), 15% to 45% (w/w), 20% to 45% (w/w), 25% to 45% (w/w), 30% to 45% (w/w), 35% to 45% (w/w), 5% to 40% (w/w), 8% to 40% (w/w), 10% to 40% (w/w), 12% to 40% (w/w), 15% to 40% (w/w), 20% to 40% (w/w), 25% to 40% (w/w), 30% to 40% (w/w), 35% to 40% (w/w), 5% to 35% (w/w), 8% to 35%

(w/w), 10% to 35% (w/w), 12% to 35% (w/w), 15% to 35% (w/w), 5% to 20% (w/w), 8% to 20% (w/w), 10% to 20% (w/w), 12% to 20% (w/w), or 15% to 20% (w/w), of alkali metal silicates, including any range therebetween. In some embodiments, the composition of the invention comprises a single alkali metal silicate. In some embodiments, the composition comprises two or more alkali metal silicates. In some embodiments, the alkali metal silicates comprise sodium silicate, lithium silicate, potassium silicate, rubidium silicate, cesium silicate, francium silicate, or any combination thereof. In some embodiments, the alkali metal silicates of the composition are substantially devoid of any alkaline earth metal. In some embodiments, the alkali metal silicate is selected from the group consisting of sodium silicate, lithium silicate, potassium silicate, rubidium silicate, cesium silicate, francium silicate, or any combination thereof. In some embodiments, the alkali metal silicate comprises lithium silicate. In some embodiments, the combined sodium silicate and potassium silicate content of the composition of the invention is up to 50%, up to 45%, up to 40%, up to 35%, up to 30%, up to 35%, up to 30%, up to 25% by weight of the composition including any range or value therebetween.

[040] In some embodiments, the composition of the invention comprises a low sodium and potassium content, so that the combined sodium and potassium weight content within the composition is at most 50%, at most 40%, at most 45%, at most 40%, at most 35%, at most 30%, at most 25%, at most 20%, including any range or value therebetween.

[041] In some embodiments, low sodium and potassium content of the composition of invention, results in a substantial reduction of oxidation of chromium to hexavalent state (e.g. during welding process), wherein reduction is as described herein. In some embodiments, low sodium and potassium content of the composition of the invention results in a substantial reduction of hexavalent chromium emission (e.g. during welding process), wherein reduction is as described herein. In some embodiments, the composition of the invention comprises a low manganese content, e.g. less than 30%, less than 20%, less than 10%, less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, less than 1% by weight of the composition, including any range or value therebetween.

[042] In some embodiments, the composition of the invention comprises 1% to 50% (w/w), 3% to 50% (w/w), 5% to 50% (w/w), 7% to 50% (w/w), 10% to 50% (w/w), 12% to 50% (w/w), 15% to 50% (w/w), 20% to 50% (w/w), 25% to 50% (w/w), 28% to 50% (w/w), 30% to 50% (w/w), 32% to 50% (w/w), 35% to 50% (w/w), 40% to 50% (w/w), 1% to 45% (w/w), 3% to 45% (w/w), 5% to 45% (w/w), 7% to 45% (w/w), 10% to 45% (w/w),

12% to 45% (w/w), 15% to 45% (w/w), 20% to 45% (w/w), 25% to 45% (w/w), 28% to 45% (w/w), 30% to 45% (w/w), 32% to 45% (w/w), 35% to 45% (w/w), 40% to 45% (w/w), 1% to 35% (w/w), 3% to 35% (w/w), 5% to 35% (w/w), 7% to 35% (w/w), 10% to 35% (w/w), 12% to 35% (w/w), 15% to 35% (w/w), 20% to 35% (w/w), 25% to 35% (w/w), 28% to 35% (w/w), 30% to 35% (w/w), 1% to 10% (w/w), 3% to 10% (w/w), 5% to 10% (w/w), or 7% to 10% (w/w) of alkali metal carbonates, including any range therebetween.

[043] In some embodiments, the composition of the invention comprises 1% to 50% (w/w), 3% to 50% (w/w), 5% to 50% (w/w), 7% to 50% (w/w), 10% to 50% (w/w), 12% to 50% (w/w), 15% to 50% (w/w), 20% to 50% (w/w), 25% to 50% (w/w), 28% to 50% (w/w), 30% to 50% (w/w), 32% to 50% (w/w), 35% to 50% (w/w), 40% to 50% (w/w), 1% to 45% (w/w), 3% to 45% (w/w), 5% to 45% (w/w), 7% to 45% (w/w), 10% to 45% (w/w), 12% to 45% (w/w), 15% to 45% (w/w), 20% to 45% (w/w), 25% to 45% (w/w), 28% to 45% (w/w), 30% to 45% (w/w), 32% to 45% (w/w), 35% to 45% (w/w), 40% to 45% (w/w), 1% to 35% (w/w), 3% to 35% (w/w), 5% to 35% (w/w), 7% to 35% (w/w), 10% to 35% (w/w), 12% to 35% (w/w), 15% to 35% (w/w), 20% to 35% (w/w), 25% to 35% (w/w), 28% to 35% (w/w), 30% to 35% (w/w), 1% to 10% (w/w), 3% to 10% (w/w), 5% to 10%

(w/w), or 7% to 10% (w/w) of alkaline earth metal carbonates, including any range therebetween.

[044] In some embodiments, the composition of the invention comprises a single alkali metal carbonate. In some embodiments, the composition of the invention comprises two or more alkali metal carbonates. In some embodiments, the alkali metal carbonate of the invention comprises any of alkaline metals (e.g. lithium, sodium, potassium, rubidium, cesium, francium) or any of alkaline earth metals (e.g. calcium, strontium, beryllium, barium, etc.). In some embodiments, the alkali metal carbonate of the invention comprises a mixture of one or more alkaline metals (e.g. lithium, sodium, potassium, rubidium, cesium, francium) and one or more of alkaline earth metals (e.g. calcium, strontium, beryllium, barium, etc.).

[045] In some embodiments, the alkali metal carbonate comprises calcium carbonate, barium carbonate, cesium carbonate, strontium carbonate, or any combination thereof. In some embodiments, the composition of the invention comprises one or more heavy alkaline metal carbonate and/or one or more heavy alkaline earth metal carbonate. In some embodiments, heavy alkaline metal carbonate comprises cesium carbonate, francium carbonate, or rubidium carbonate, or any combination thereof. In some embodiments, heavy alkaline earth metal carbonate comprises barium carbonate, strontium carbonate, or calcium carbonate or any combination thereof.

[046] In some embodiments, the composition comprises 5% to 30% (w/w), 6% to 30% (w/w), 7% to 30% (w/w), 8% to 30% (w/w), 10% to 30% (w/w), 12% to 30% (w/w), 15% to 30% (w/w), 18% to 30% (w/w), 20% to 30% (w/w), 25% to 30% (w/w), 5% to 20% (w/w), 6% to 20% (w/w), 7% to 20% (w/w), 8% to 20% (w/w), 10% to 20% (w/w), 12% to 20% (w/w), 15% to 20% (w/w), 5% to 18% (w/w), 6% to 18% (w/w), 7% to 18% (w/w), 8% to 18% (w/w), 10% to 18% (w/w), 12% to 18% (w/w), 15% to 18% (w/w), 5% to 15% (w/w), 6% to 15% (w/w), 7% to 15% (w/w), 8% to 15% (w/w), 10% to 15% (w/w), or 12% to 15% (w/w), calcium carbonate, including any range therebetween.

[047] In some embodiments, the composition comprises 0.5% to 5% (w/w), 0.9% to 5% (w/w), 1% to 5% (w/w), 1.5% to 5% (w/w), 2% to 5% (w/w), 2.5% to 5% (w/w), 3% to 5% (w/w), 3.5% to 5% (w/w), 4% to 5% (w/w), 4.5% to 5% (w/w), 0.5% to 4.2% (w/w), 0.9% to 4.2% (w/w), 1.5% to 4.2% (w/w), 2% to 4.2% (w/w), 2.5% to 4.2% (w/w), 3% to 4.2% (w/w), 3.5% to 4.2% (w/w), 0.5% to 3.5% (w/w), 0.9% to 3.5% (w/w), 1.5% to 3.5% (w/w), 2% to 3.5% (w/w), 2.5% to 3.5% (w/w), or 3% to 3.5% (w/w), barium carbonate, including any range therebetween. [048] In some embodiments, the composition comprises 0.5% to 5% (w/w), 0.9% to 5% (w/w), 1% to 5% (w/w), 1.5% to 5% (w/w), 2% to 5% (w/w), 2.5% to 5% (w/w), 3% to 5% (w/w), 3.5% to 5% (w/w), 4% to 5% (w/w), or 4.5% to 5% (w/w), 0.5% to 4.2% (w/w), 0.9% to 4.2% (w/w), 1.5% to 4.2% (w/w), 2% to 4.2% (w/w), 2.5% to 4.2% (w/w), 3% to 4.2% (w/w), 3.5% to 4.2% (w/w), 0.5% to 3.5% (w/w), 0.9% to 3.5% (w/w), 1.5% to 3.5%

(w/w), 2% to 3.5% (w/w), 2.5% to 3.5% (w/w), 3% to 3.5% (w/w), strontium carbonate, including any range therebetween.

[049] In some embodiments, the composition comprises 1% to 20% (w/w), 2% to 20% (w/w), 3% to 20% (w/w), 4% to 20% (w/w), 5% to 20% (w/w), 6% to 20% (w/w), 7% to 20% (w/w), 8% to 20% (w/w), 10% to 20% (w/w), 12% to 20% (w/w), 15% to 20% (w/w),

0.5% to 18% (w/w), 1% to 18% (w/w), 2% to 18% (w/w), 3% to 18% (w/w), 4% to 18% (w/w), 5% to 18% (w/w), 6% to 18% (w/w), 7% to 18% (w/w), 8% to 18% (w/w), 10% to 18% (w/w), 12% to 18% (w/w), 15% to 18% (w/w), 0.5% to 15% (w/w), 1% to 15% (w/w), 2% to 15% (w/w), 3% to 15% (w/w), 4% to 15% (w/w), 5% to 15% (w/w), 6% to 15% (w/w), 7% to 15% (w/w), 8% to 15% (w/w), 10% to 15% (w/w), or 12% to 15% (w/w), low carbon ferro-alloy, including any range therebetween. In some embodiments, the low carbon ferro-alloy comprises low carbon ferro-manganese, low carbon ferro -chromium, or both.

[050] In some embodiments, the medium carbon ferro-alloy comprises low carbon ferro- manganese, low carbon ferro-chromium, or both.

[051] In some embodiments, the low carbon ferro-alloy comprises low carbon ferro- chromium. In some embodiments, the composition comprises 5% to 15% (w/w), 7% to 15% (w/w), 9% to 15% (w/w), 10% to 15% (w/w), 5% to 12% (w/w), 7% to 12% (w/w), 9% to 12% (w/w), or 10% to 12% (w/w), low carbon ferro-chromium, including any range therebetween. [052] In some embodiments, the low carbon ferro-alloy comprises low carbon ferro manganese. In some embodiments, the composition comprises 0.1% to 3% (w/w), 0.2% to 3% (w/w), 0.3% to 3% (w/w), 0.5% to 3% (w/w), 0.7% to 3% (w/w), 0.9% to 3% (w/w), 1% to 3% (w/w), 1.5% to 3% (w/w), 2% to 3% (w/w), 0.1% to 2.5% (w/w), 0.2% to 2.5% (w/w), 0.3% to 2.5% (w/w), 0.5% to 2.5% (w/w), 0.7% to 2.5% (w/w), 0.9% to 2.5% (w/w),

1% to 2.5% (w/w), 1.5% to 2.5% (w/w), 0.1% to 1.9% (w/w), 0.2% to 1.9% (w/w), 0.3% to 1.9% (w/w), 0.5% to 1.9% (w/w), 0.7% to 1.9% (w/w), or 0.9% to 1.9% (w/w), low carbon ferro-manganese, including any range therebetween.

[053] The term "ferromanganese" refers to a ferroalloy with high content of manganese. Non-limiting examples for providing ferromanganese is by heating a mixture of the oxides MnC and FeiC , with carbon.

[054] In some embodiments, the manganese content is in the range of 1% to 7% (w/w), 1.5% to 7% (w/w), 1.5% to 6% (w/w), 2% to 5% (w/w), 2% to 4% (w/w), or 2.5% to 3% (w/w), including any range therebetween.

[055] In some embodiments, the manganese comprises a ferromanganese compound. In some embodiments, ferromanganese compound weight content is in the range of 0.5% to 10% (w/w), 1% to 10% (w/w), 1% to 9% (w/w), 2% to 10% (w/w), 2% to 9% (w/w), 3% to 9% (w/w), 5% to 7% (w/w), including any range therebetween.

[056] In some embodiments, the composition comprises nitrogen as a substitute for manganese. In some embodiments, the composition comprises nitrided ferrochromium. In some embodiments, the composition comprises nitrided chromium. In some embodiments, least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 45%, at least 50%, at least 60%, or at least 70%, of the ferrochromium content is replaced by nitrided ferrochromium. Nitrided metals and nitrided alloys are well-known in the art. [057] In some embodiments, the composition comprises an alloying element (also referred to as: "alloying agent"). In some embodiments, the alloying element is selected from, without being limited thereto, iron, molybdenum, nickel, copper, chromium, manganese, ferromanganese, boric acid, nickel, ferrotitanium, titanium, ferro-niobium, niobium, cupper, nitrided ferrochromium, or any combination thereof. In some embodiments, the nickel is in the form of a nickel powder.

[058] In some embodiments, the composition comprises 5% to 50% (w/w), 9% to 50% (w/w), 10% to 50% (w/w), 15% to 50% (w/w), 20% to 50% (w/w), 22% to 50% (w/w), 25% to 50% (w/w), 28% to 50% (w/w), 30% to 50% (w/w), 32% to 50% (w/w), 35% to 50% (w/w), 40% to 50% (w/w), 5% to 45% (w/w), 9% to 45% (w/w), 10% to 45% (w/w), 15% to 45% (w/w), 20% to 45% (w/w), 22% to 45% (w/w), 25% to 45% (w/w), 28% to 45% (w/w), 30% to 45% (w/w), 32% to 45% (w/w), 35% to 45% (w/w), 40% to 45% (w/w), 5% to 30% (w/w), 9% to 30% (w/w), 10% to 30% (w/w), 15% to 30% (w/w), 20% to 30% (w/w), 22% to 30% (w/w), 25% to 30% (w/w), 28% to 30% (w/w), 20% to 38% (w/w), 22% to 38% (w/w), 25% to 38% (w/w), 28% to 38% (w/w), or 30% to 38% (w/w), aluminum silicates, including any range therebetween. In some embodiments, the aluminum silicates comprise kyanite, silitin, calcinated kaolinite, petalite, spodumene, bentonite, china clay or any combination thereof.

[059] In some embodiments, the composition comprises 1% to 8% (w/w), 2% to 8% (w/w), 2.5% to 8% (w/w), 3% to 8% (w/w), 3.5% to 8% (w/w), 4% to 8% (w/w), 4.5% to 8% (w/w), 5% to 8% (w/w), 6 to 8% (w/w), 1% to 7.5% (w/w), 2% to 7.5% (w/w), 2.5% to 7.5% (w/w), 3% to 7.5% (w/w), 3.5% to 7.5% (w/w), 4% to 7.5% (w/w), 4.5% to 7.5% (w/w), 5% to 7.5% (w/w), 6 to 7.5% (w/w), 1% to 5% (w/w), 2% to 5% (w/w), 2.5% to 5% (w/w), 3% to 5% (w/w), 3.5% to 5% (w/w), 4% to 5% (w/w), or 4.5% to 5% (w/w), titanium dioxide, including any range therebetween. [060] In some embodiments, the composition comprises 1% to 7% (w/w), 1% to 5% (w/w), 1.5% to 5% (w/w), 2% to 5% (w/w), 2.5% to 5% (w/w), 3% to 5% (w/w), 3.5% to 5% (w/w), 4% to 5% (w/w), or 4.5% to 5% (w/w), 1.5% to 4.2% (w/w), 2% to 4.2% (w/w), 2.5% to 4.2% (w/w), 3% to 4.2% (w/w), 3.5% to 4.2% (w/w), 1.5% to 3.5% (w/w), 2% to 3.5% (w/w), 2.5% to 3.5% (w/w), 3% to 3.5% (w/w), calcium fluoride, including any range therebetween. In some embodiments, the composition comprises 1% to 7% (w/w), 1% to 5% (w/w), 1.5% to 5% (w/w), 2% to 5% (w/w), 2.5% to 5% (w/w), 3% to 5% (w/w), 3.5% to 5% (w/w), 4% to 5% (w/w), or 4.5% to 5% (w/w), 1.5% to 4.2% (w/w), 2% to 4.2% (w/w), 2.5% to 4.2% (w/w), 3% to 4.2% (w/w), 3.5% to 4.2% (w/w), 1.5% to 3.5% (w/w), 2% to 3.5% (w/w), 2.5% to 3.5% (w/w), 3% to 3.5% (w/w), fluorspar, including any range therebetween.

[061] In some embodiments, the composition comprises 0.2% to 3% (w/w), 0.5% to 3% (w/w), 0.9% to 3% (w/w), 1% to 3% (w/w), 1.5% to 3% (w/w), 2% to 3% (w/w), 2.5% to 3% (w/w), 0.2% to 2.9% (w/w), 0.5% to 2.9% (w/w), 0.9% to 2.9% (w/w),l% to 2.9% (w/w), 1.5% to 2.9% (w/w), 2% to 2.9% (w/w), 0.2% to 2.5% (w/w), 0.5% to 2.5% (w/w), 0.9% to 2.5% (w/w),l% to 2.5% (w/w), 1.5% to 2.5% (w/w), or 2% to 2.5% (w/w), of a slip agent, including any range therebetween. In some embodiments, the slip agent is selected from carboxymethylcellulose (CMC), hydroxyethyl cellulose, calcium alginate, guar gum, talc, clay, and any combination thereof. As used herein, the term“slip agent” refers to an external lubricant. In some embodiments, the slip agent comprises an inorganic compound (such as talc, clay, china clay, calcium carbonate, silica, etc.), a polysaccharide (such as cellulose, modified cellulose, starch, modified starch, carboxymethylcellulose (CMC), hydroxyethyl cellulose, hydroxymethyl cellulose, hydroxypropyl cellulose, alkylated cellulose, a gum, tragacanth, carrageenan, guar gum, agar, etc.) or any combination thereof. In some embodiments, the slip agent is substantially devoid of a synthetic polymer or a synthetic resin such as polyvinylchloride, a polyolefine, a polyacrylate, a thermoset polymer (e.g. Bakelite, urea-formaldehyde, melamine, epoxy, etc.)

[062] In some embodiments, the composition comprises 0.2% to 2% (w/w), 0.3% to 2% (w/w), 0.4% to 2% (w/w), 0.5% to 2% (w/w), 0.7% to 2% (w/w), 0.8% to 2% (w/w), 0.9% to 2% (w/w), 1% to 2% (w/w), 1.2% to 2% (w/w), 1.4% to 2% (w/w), 1.5% to 2% (w/w), 0.2% to 1.9% (w/w), 0.3% to 1.9% (w/w), 0.4% to 1.9% (w/w), 0.5% to 1.9% (w/w), 0.7% to 1.9% (w/w), 0.8% to 1.9% (w/w), 0.9% to 1.9% (w/w), 1% to 1.9% (w/w), 1.2% to 1.9% (w/w), 1.4% to 1.9% (w/w), 1.5% to 1.9% (w/w), 0.2% to 1.5% (w/w), 0.3% to 1.5% (w/w), 0.4% to 1.5% (w/w), 0.5% to 1.5% (w/w), 0.7% to 1.5% (w/w), 0.8% to 1.5% (w/w), 0.9% to 1.5% (w/w), 1% to 1.5% (w/w), 1.2% to 1.5% (w/w), 0.2% to 0.9% (w/w), 0.3% to 0.9% (w/w), 0.4% to 0.9% (w/w), 0.5% to 0.9% (w/w), 0.7% to 0.9% (w/w), 0.8% to 0.9% (w/w), CMC, including any range therebetween.

[063] In some embodiments, the composition comprises 0.2% to 2% (w/w), 0.3% to 2% (w/w), 0.4% to 2% (w/w), 0.5% to 2% (w/w), 0.7% to 2% (w/w), 0.8% to 2% (w/w), 0.9% to 2% (w/w), 1% to 2% (w/w), 1.2% to 2% (w/w), 1.4% to 2% (w/w), 1.5% to 2% (w/w), 0.2% to 1.9% (w/w), 0.3% to 1.9% (w/w), 0.4% to 1.9% (w/w), 0.5% to 1.9% (w/w), 0.7% to 1.9% (w/w), 0.8% to 1.9% (w/w), 0.9% to 1.9% (w/w), 1% to 1.9% (w/w), 1.2% to 1.9% (w/w), 1.4% to 1.9% (w/w), 1.5% to 1.9% (w/w), 0.2% to 1.5% (w/w), 0.3% to 1.5% (w/w), 0.4% to 1.5% (w/w), 0.5% to 1.5% (w/w), 0.7% to 1.5% (w/w), 0.8% to 1.5% (w/w), 0.9% to 1.5% (w/w), 1% to 1.5% (w/w), 1.2% to 1.5% (w/w), 0.2% to 0.9% (w/w), 0.3% to 0.9% (w/w), 0.4% to 0.9% (w/w), 0.5% to 0.9% (w/w), 0.7% to 0.9% (w/w), 0.8% to 0.9% (w/w), hydroxy ethyl cellulose, including any range therebetween.

[064] In some embodiments, the composition comprises 1% to 3% (w/w), 1.5% to 3% (w/w), 2% to 3% (w/w), 2.5% to 3% (w/w), 1% to 2.9% (w/w), 1.5% to 2.9% (w/w), 2% to 2.9% (w/w), 1% to 2.5% (w/w), 1.5% to 2.5% (w/w), or 2% to 2.5% (w/w), of china clay, including any range therebetween.

[065] In some embodiments, the composition comprises 0.1% to 1% (w/w), 0.2% to 1% (w/w), 0.3% to 1% (w/w), 0.5% to 1% (w/w), 0.7% to 1% (w/w), 0.9% to 1% (w/w), 0.1% to 0.9% (w/w), 0.2% to 0.9% (w/w), 0.3% to 0.9% (w/w), 0.5% to 0.9% (w/w), 0.7% to 0.9% (w/w), 0.1% to 0.5% (w/w), 0.2% to 0.5% (w/w), or 0.3% to 0.5% (w/w), calcium sulfate, including any range therebetween. In some embodiments, the composition comprises 0.1% to 1% (w/w), 0.2% to 1% (w/w), 0.3% to 1% (w/w), 0.5% to 1% (w/w), 0.7% to 1% (w/w), 0.9% to 1% (w/w), 0.1% to 0.9% (w/w), 0.2% to 0.9% (w/w), 0.3% to 0.9% (w/w), 0.5% to 0.9% (w/w), 0.7% to 0.9% (w/w), 0.1% to 0.5% (w/w), 0.2% to 0.5% (w/w), or 0.3% to 0.5% (w/w), gypsum, including any range therebetween.

[066] In some embodiments, the composition comprises 0.1% to 1% (w/w), 0.2% to 1% (w/w), 0.3% to 1% (w/w), 0.5% to 1% (w/w), 0.7% to 1% (w/w), 0.9% to 1% (w/w), 0.1% to 0.9% (w/w), 0.2% to 0.9% (w/w), 0.3% to 0.9% (w/w), 0.5% to 0.9% (w/w), 0.7% to 0.9% (w/w), 0.1% to 0.5% (w/w), 0.2% to 0.5% (w/w), or 0.3% to 0.5% (w/w), calcium silicate, including any range therebetween. In some embodiments, the composition comprises 0.1% to 1% (w/w), 0.2% to 1% (w/w), 0.3% to 1% (w/w), 0.5% to 1% (w/w), 0.7% to 1% (w/w), 0.9% to 1% (w/w), 0.1% to 0.9% (w/w), 0.2% to 0.9% (w/w), 0.3% to 0.9% (w/w), 0.5% to 0.9% (w/w), 0.7% to 0.9% (w/w), 0.1% to 0.5% (w/w), 0.2% to 0.5% (w/w), or 0.3% to 0.5% (w/w), cement, including any range therebetween.

[067] In some embodiments, the composition comprises or consist essentially of rutile, a plurality of alkali metal silicates (e.g. sodium silicate and lithium silicate), one or more of alkaline metal carbonate, and/or one or more of alkaline earth metal carbonate. In some embodiments, the composition comprises or consist essentially of rutile, a plurality of alkali metal silicates, and one or more alkali metal carbonate (e.g. lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate or any combination thereof). In some embodiments, the composition comprises or consist essentially of rutile, a plurality of alkali metal silicates, and one or more alkali earth metal carbonate (e.g. calcium carbonate, barium carbonate, strontium carbonate or any combination thereof). In some embodiments, the composition of the invention comprises or consist essentially of rutile, a plurality of alkali metal silicates, and one or more alkali metal carbonate, and/or one or more of alkaline earth metal carbonate, wherein the w/w concentrations of the components within the composition are as described herein. In some embodiments, the composition of the invention comprises a single alkali metal silicate. In some embodiments, the composition of the invention comprises a plurality of alkali metal silicates comprising at least two of sodium silicate, lithium silicate, potassium silicate, rubidium silicate, cesium silicate.

[068] In some embodiments, the composition of the invention comprises or consist essentially of rutile, a plurality of alkali metal silicates, one or more of alkaline metal carbonate and/or of alkaline earth metal carbonate, and a low carbon ferro-alloy. In some embodiments, the composition of the invention comprises or consist essentially of rutile, a plurality of alkali metal silicates, one or more of alkaline metal carbonate and/or of alkaline earth metal carbonate, and a low carbon ferro-alloy wherein the w/w concentrations of the components within the composition are as described herein.

[069] In some embodiments, the composition of the invention comprises or consist essentially of rutile, a plurality of alkali metal silicates, one or more of alkaline metal carbonate and/or of alkaline earth metal carbonate, a low carbon ferro-alloy, and aluminum silicate. In some embodiments, the composition of the invention comprises or consist essentially of rutile, a plurality of alkali metal silicates, one or more of alkaline metal carbonate and/or of alkaline earth metal carbonate, a low carbon ferro-alloy, and aluminum silicate wherein the w/w concentrations of the components within the composition are as described herein.

[070] In some embodiments, the composition of the invention comprises or consist essentially of rutile, an alkali metal silicate, one or more of alkaline metal carbonate and/or of alkaline earth metal carbonate, a low carbon ferro-alloy, aluminum silicate, and optionally at least one of titanium dioxide and the slip agent. In some embodiments, the composition of the invention comprises or consist essentially of rutile, a plurality of alkali metal silicates, one or more of alkaline metal carbonate and/or of alkaline earth metal carbonate, a low carbon ferro-alloy, aluminum silicate, and optionally at least one of titanium dioxide and the slip agent. In some embodiments, the composition of the invention comprises or consist essentially of rutile, a plurality of alkali metal silicates, one or more of alkaline metal carbonate and/or of alkaline earth metal carbonate, a low carbon ferro-alloy, aluminum silicate, and optionally at least one of titanium dioxide and the slip agent wherein the w/w concentrations of the components within the composition are as described herein.

[071] In some embodiments, the composition of the invention comprises or consist essentially of between 25 and 45% w/w rutile, between 4 and 45% w/w of a plurality of alkali metal silicates (optionally between 5 and 10%, between 10 and 15%, between 15 and 20%, between 20 and 25%, between 25 and 30% by weight of sodium silicate and optionally between 5 and 10%, between 10 and 15%, between 15 and 20%, between 20 and 25%, between 25 and 30% by weight of lithium silicate), between 5 and 50% w/w of one or more of alkaline metal carbonate and/or of alkaline earth metal carbonate, between 5 and 20% w/w of a low carbon ferro-alloy, between 5 and 50% w/w of aluminum silicate, and optionally between 0.2 and 8% w/w of at least one of titanium dioxide and the slip agent.

[072] In some embodiments, the composition of the invention comprises or consist essentially of between 25 and 45% w/w rutile, between 4 and 45% w/w of a plurality of alkali metal silicates (optionally between 5 and 10%, between 10 and 15%, between 15 and 20%, between 20 and 25%, between 25 and 30% by weight of sodium silicate and optionally between 5 and 10%, between 10 and 15%, between 15 and 20%, between 20 and 25%, between 25 and 30% by weight of lithium silicate), between 5 and 50% w/w of one or more of alkaline metal carbonate (e.g. cesium carbonate) and/or of alkaline earth metal carbonate (e.g. barium carbonate and/or strontium carbonate), between 5 and 20% w/w of a low carbon ferro-alloy (e.g. low carbon ferro-chromium, low carbon ferro-manganese or both, wherein the ferro alloy is optionally nitrided), between 5 and 50% w/w of aluminum silicate, and optionally between 0.2 and 8% w/w of at least one of titanium dioxide and the slip agent.

[073] In some embodiments, the composition is in the form of a coating on a substrate. In some embodiments, the substrate comprises one or more metals. In some embodiments, the metal is an iron based alloy. In some embodiments, the iron based alloy is selected from, without being limited thereto, cast iron, and ductile iron, steel alloy comprising e.g., carbon steel, low and high alloy steel, stainless steel, cast iron, or ductile iron. In some embodiments, the metal is a nonferrous material. In some embodiments, the nonferrous material is selected from, without being limited thereto, nickel and copper, and their alloys, and aluminum.

The article

[074] According to some embodiments of the present invention there is provided an article comprising the composition described herein in an embodiment thereof. In some embodiments, the article comprises a metal wire. In some embodiments, the composition described herein is in the form of a coating on at least one surface of the metal wire. In some embodiments, the coating is as described herein. [075] In some embodiments, the article is a tubular welding wire. In some embodiments, the tubular welding wire is characterized by a diameter core metal wire in the range of from

1 mm to 6 mm. In some embodiments, the tubular welding wire is characterized by a diameter core metal wire in the range of from 1.5 mm to 6 mm, 1.6 mm to 6 mm, 2 mm to 6 mm, 3 mm to 6 mm, 4 mm to 6 mm, 1 mm to 5 mm, 1.5 mm to 5 mm, 1.6 mm to 5 mm,

2 mm to 5 mm, 3 mm to 5 mm, 3 mm to 4 mm, 3 mm to 3.5 mm, or 4 mm to 6 mm, including any range therebetween.

[076] The phrase "welding wire" refers to a slim metallic rod that is ignited to generate a heated arc e.g., for the purpose of fusing metal pieces together (welding) by rendering the wire soft via hammering or compressing under an applied heat source. In arc welding, an electrode may be used to conduct current through a work piece to fuse two pieces together. Depending upon the process, the electrode may be either consumable, e.g., in the case of gas metal arc welding or shielded metal arc welding, or non-consumable, such as in gas tungsten arc welding.

[077] In some embodiments, the article comprises the coating described herein, is in the form of a welding flux.

[078] The phrase "welding flux" refers to the insulating covering of the metal core welding wire. The flux may give off gases as it decomposes to prevent weld contamination, introduce deoxidizers to purify the weld, cause weld-protecting slag to form, improve the arc stability, or may provide alloying elements to improve the weld quality.

[079] In some embodiments, the article is a shielded arc electrode.

[080] The phrase "shielded arc electrode" refers to a welding wire coated with welding flux that driven the shielded metal arc welding process, in which an electrical circuit may be established to strike an arc between the electrode and the metal substrates, providing heat source, whereas further the coated wire may be melted to fill spaces between parts. [081] In some embodiments, the shielded arc electrode is a welding consumable.

[082] The phrase "welding consumable" may refer to a welding wire, or a flux coated wire, that consume during the arc welding process, providing the materials and atmospheric protection to the weld zone. In some embodiments, the article of the invention comprises a singe coating layer. In some embodiments, the article of the invention is substantially devoid of multiple coating layers. In some embodiments, the article of the invention comprises a metal wire core substantially in contact with the coating described herein. In some embodiments, the article of the invention comprises a metal wire core and the coating, wherein the core and the coating form substantially consecutive layers. In some embodiments, the coating as described herein faces the ambient (e.g. the coating is in a form of an outer layer and/or in a form of a shell). In some embodiments, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 85%, at least 90%, at least 95%, at least 92%, at least 97% of the surface of the core (e.g. metal wire core) is in contact with or bound to the coating, wherein the coating is as described herein.

[083] In some embodiments, the article is characterized by weld metal ductility of 20% to 70%, 20% to 68%, 20% to 65%, 20% to 55%, 20% to 50%, 22% to 50%, 25% to 50%, 28% to 50%, 30% to 50%, 32% to 50%, 35% to 50%, 40% to 50%, 20% to 48%, 22% to 48%, 25% to 48%, 28% to 48%, 30% to 48%, 32% to 48%, 35% to 48%, 40% to 48%, 20% to 45%, 22% to 45%, 25% to 45%, 28% to 45%, 30% to 45%, 32% to 45%, 35% to 45%, 35% to 70%, 35% to 68%, 35% to 65%, 35% to 55%, 40% to 45%, 40% to 70%, 40% to

68%, 40% to 65%, or 40% to 55%, elongation as compared to the original material length, including any range therebetween.

[084] As used herein, the term“ductility” refers to a physical property of a material associated with the ability to be hammered thin or stretched into wire without breaking. Ductility is a measure of a material's ability to withstand tensile stress— any force that pulls the two ends of an object away from each other.

[085] In some embodiments, the article is characterized by ultimate tensile strength (UTS) of 5 MPa to 1000 MPa, 10 MPa to 1000 MPa, 15 MPa to 1000 MPa, 25 MPa to 1000 MPa, 50 MPa to 1000 MPa, 80 MPa to 1000 MPa, 100 MPa to 1000 MPa, 250 MPa to 1000 MPa, 500 MPa to 1000 MPa, 700 MPa to 1000 MPa, 800 MPa to 1000 MPa, 5 MPa to 500 MPa, 10 MPa to 500 MPa, 15 MPa to 500 MPa, 25 MPa to 500 MPa, 50 MPa to 500 MPa, 80 MPa to 500 MPa, 100 MPa to 500 MPa, 250 MPa to 500 MPa, 5 MPa to 250 MPa, 10 MPa to 250 MPa, 15 MPa to 250 MPa, 25 MPa to 250 MPa, 50 MPa to 250 MPa, 80 MPa to 250 MPa, or 100 MPa to 250 MPa, including any range therebetween.

[086] In some embodiments, the article is characterized by yield point of 400 MPa to 600 MPa, 420 MPa to 600 MPa, 450 MPa to 600 MPa, 500 MPa to 600 MPa, 520 MPa to 600 MPa, 550 MPa to 600 MPa, 400 MPa to 580 MPa, 420 MPa to 580 MPa, 450 MPa to 580 MPa, 500 MPa to 580 MPa, 520 MPa to 580 MPa, 550 MPa to 580 MPa, 400 MPa to 500 MPa, 420 MPa to 500 MPa, or 450 MPa to 500 MPa, including any range therebetween.

[087] In some embodiments, the article is characterized by a fume emission rate in the range of 0.1 g/Kg to 6 g/Kg, 0.5 g/Kg to 6 g/Kg, 0.9 g/Kg to 6 g/Kg, 1 g/Kg to 6 g/Kg, 1.2 g/Kg to 6 g/Kg, 1.5 g/Kg to 6 g/Kg, 1.9 g/Kg to 6 g/Kg, 2 g/Kg to 6 g/Kg, 3 g/Kg to 6 g/Kg, 4 g/Kg to 6 g/Kg, 0.1 g/Kg to 5 g/Kg, 0.5 g/Kg to 5 g/Kg, 0.9 g/Kg to 5 g/Kg, 1 g/Kg to 5 g/Kg, 1.2 g/Kg to 5 g/Kg, 1.5 g/Kg to 5 g/Kg, 1.9 g/Kg to 5 g/Kg, 2 g/Kg to 5 g/Kg, 3 g/Kg to 5 g/Kg, 4 g/Kg to 5 g/Kg, 0.1 g/Kg to 2 g/Kg, 0.5 g/Kg to 2 g/Kg, 0.9 g/Kg to 2 g/Kg, 1 g/Kg to 2 g/Kg, 1.2 g/Kg to 2 g/Kg, 1.5 g/Kg to 2 g/Kg, for core wire diameter in the range of 3 mm to 3. 5 mm, including any range therebetween.

[088] In some embodiments, the article is characterized by a hexavalent chromium emission rate in the range of 0.01 g/Kg to 0.2 g/Kg, 0.02 g/Kg to 0.2 g/Kg, 0.03 g/Kg to 0.2 g/Kg, 0.05 g/Kg to 0.2 g/Kg, 0.09 g/Kg to 0.2 g/Kg, 0.1 g/Kg to 0.2 g/Kg, 0.01 g/Kg to 0.15 g/Kg, 0.02 g/Kg to 0.15 g/Kg, 0.03 g/Kg to 0.15 g/Kg, 0.05 g/Kg to 0.15 g/Kg, 0.09 g/Kg to 0.15 g/Kg, 0.1 g/Kg to 0.15 g/Kg, 0.01 g/Kg to 0.1 g/Kg, 0.02 g/Kg to 0.1 g/Kg, 0.03 g/Kg to 0.1 g/Kg, 0.05 g/Kg to 0.1 g/Kg, or 0.09 g/Kg to 0.1 g/Kg, for core wire diameter in the range of 3 mm to 3. 5 mm, including any range therebetween.

[089] In some embodiments, the article and/or the composition of the invention is characterized by reduced oxidation of chromium to hexavalent state. In some embodiments, the article and/or the composition of the invention is characterized by reduced oxidation of chromium to hexavalent state, compared to other commercially available articles (e.g. electrode and/or welding electrode). In some embodiments, the term“reduced” in any grammatical form thereof is referred to 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95%, reduction including any range or value therebetween.

[090] In some embodiments, the article is characterized by a reduction of the total fume emission rate during welding process when compared to the total fume emission rate of a standard electrode. In some embodiments, the article is characterized by a 5%, 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95%, reduction of the total fume emission rate during welding process when compared to the total fume emission rate of a standard electrode.

[091] In some embodiments, the article is characterized by reduction of the rate emission of hexavalent chromium during welding process when compared to the rate emission of hexavalent chromium of a standard electrode. In some embodiments, the article is characterized by a 5%, 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95%, reduction of the rate emission of hexavalent chromium during welding process when compared to the rate emission of hexavalent chromium of a standard electrode. [092] In some embodiments, the article is characterized by a reduction of the rate emission of manganese during welding process when compared to the rate emission of manganese of a standard electrode. In some embodiments, the article is characterized by a 5%, 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95%, reduction of the rate emission of manganese during welding process when compared to the rate emission of manganese of a standard electrode.

General

[093] As used herein the term“about” refers to ± 10 %.

[094] The terms "comprises", "comprising", "includes", "including",“having” and their conjugates mean "including but not limited to".

[095] The term“consisting of means“including and limited to”.

[096] The term "consisting essentially of" means that the composition, method or structure may include additional ingredients, steps and/or parts, but only if the additional ingredients, steps and/or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure.

[097] The word“exemplary” is used herein to mean“serving as an example, instance or illustration”. Any embodiment described as“exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments and/or to exclude the incorporation of features from other embodiments.

[098] The word“optionally” is used herein to mean“is provided in some embodiments and not provided in other embodiments”. Any particular embodiment of the invention may include a plurality of“optional” features unless such features conflict.

[099] As used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" may include a plurality of compounds, including mixtures thereof. [0100] As used herein, the term“substantially” is at least 80%, at least 90%, at least 92%, at least 95%, at least 97%, at least 98%, at least 99% by weight of the composition including any range or value therebetween.

[0101] Throughout this application, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0102] Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases“ranging/ranges between” a first indicate number and a second indicate number and“ranging/ranges from” a first indicate number“to” a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween.

[0103] As used herein the term "method" refers to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the chemical, pharmacological, biological, biochemical and medical arts.

[0104] As used herein, the term“treating” includes abrogating, substantially inhibiting, slowing or reversing the progression of a condition, substantially ameliorating clinical or aesthetical symptoms of a condition or substantially preventing the appearance of clinical or aesthetical symptoms of a condition.

[0105] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

[0106] Various embodiments and aspects of the present invention as delineated hereinabove and as claimed in the claims section below find experimental support in the following examples. EXAMPLES

[0107] Reference is now made to the following examples, which together with the above descriptions illustrate some embodiments of the invention in a non-limiting fashion.

EXAMPLE 1

Low Hexa valent Chromium Emission Coated Welding Electrode

[0108] The most harmful substrates, which are emitted during welding of stainless steel, are hexavalent chromium compounds. They are defined as carcinogen substances. The electrode of the present invention, welding Electrode 1 (Table 1 and Table 2), has a significantly reduced emission of hexavalent chromium. Reduction of hexavalent chromium emission requires cutting down significantly the content of alkali metals in the flux. Strontium and barium can be alternative materials in some terms to sodium and potassium because of their relatively low ionization energy. Usage of this carbonate helps to reduce ionization energy of welding arc and by such a way to improve discharge

(glowing) stability.

Table 1.

Table 2.

[0109] The total fume rate emission of Electrode 1 is reduced up to 40% and the rate of hexavalent chromium emission is lowered up to 50% (Figure 1 and Figure 2).

[0110] Table 3 presents mechanical properties of welding Electrode 1. Table 3.

[0111] Tests for the characterization of welding profiles were carried out. As a reference, two other samples were selected and compared to welding Electrode 1: a standard electrode and standard electrode 1, which does not include potassium silicate and carbonate barium and strontium. The experiments were performed for electrodes with a diameter of 3.25 mm (Table 4).

Table 4.

*FER - Fume Emission Rate

[0112] In terms of welding performance, welding Electrode 1 has a significant advantage over the standard electrode 1 used as comparison reference. Overall, welding Electrode 1 allows reducing the emission of chromium 6+ by 53% and general smoke flux emissions by 41% compared to a standard electrode of reference.

[0113] Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. [0114] All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting.

Claims

CLAIMS What is claimed is:

1. A composition comprising 25% to 45% (w/w) rutile, 4% to 45% (w/w) alkali metal silicates, and 5% to 50% (w/w) alkali metal carbonate.

2. The composition of claim 1, wherein said alkali metal silicates comprise at least two silicates selected from sodium silicate, lithium silicate, potassium silicate, rubidium silicate, cesium silicate, and francium silicate.

3. The composition of claim 1, wherein said alkali metal carbonate comprise calcium carbonate, barium carbonate, cesium carbonate, strontium carbonate, or any combination thereof.

4. The composition of any one of claims 1 to 3, comprising 5% to 20% (w/w) low carbon ferro-alloy.

5. The composition of claim 4, wherein said low carbon ferro-alloy comprises low carbon ferro-manganese, low carbon ferro -chromium, or both.

6. The composition of any one of claims 1 to 5, comprising 5% to 50% (w/w) aluminum silicate.

7. The composition of claim 6, wherein said aluminum silicate comprise kyanite, silitin, calcinated kaolinite, petalite, spodumene, bentonite, china clay or any combination thereof.

8. The composition of any one of claims 1 to 7, comprising 1% to 8% (w/w) of titanium dioxide.

9. The composition of any one of claims 1 to 8, comprising 1% to 7% (w/w) fluorspar.

10. The composition of any one of claims 1 to 9, comprising 0.2% to 3% (w/w) of a slip agent.

11. The composition of claim 10, wherein said slip agent is selected from carboxymethylcellulose (CMC), hydroxyethyl cellulose, calcium alginate, guar gum, talc, clay, and any combination thereof.

12. The composition of any one of claims 1 to 11, being in the form of a coating on a substrate.

13. The composition of claim 12, wherein said substrate comprises one or more metals.

14. An article comprising the composition of any one of claims 1 to 13.

15. The article of claim 14, comprising a metal wire and said composition being in the form of a coating on at least one surface of said article.

16. The article of any one of claims 14 and 15, wherein said article is a tubular welding wire.

17. The article of claim 16, wherein the welding wire is characterized by a diameter of a core metal wire in the range of 1 mm to 6 mm.

18. The article of any one of claims 14 to 17, wherein said coating is in the form of a welding flux.

19. The article of any one of claims 14 to 18, wherein said article is a shielded arc welding electrode.

20. The article of claim 19, wherein said shielded arc electrode is a welding consumable.

21. The article of any one of claims 14 to 20, characterized by weld metal ductility of 20% to 70% elongation as compared to the original material length.

22. The article of any one of claims 14 to 21, characterized by ultimate tensile strength (UTS) of 5 MPa to 1000 MPa.

23. The article of any one of claims 14 to 22, characterized by yield point of 400 MPa to 600 MPa.