Multi-coated electrode for welding stainless steel
AssigneeDuctil SA
InventorSorin Craciun
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Abstract
The invention relates to a coated electrode comprising a central metal core being surrounded at least in part by an outer coating containing rutile and at least one lithium-based compound and being free of sodium feldspar and potassium feldspar. According to the invention, the electrode comprises at least one inner coating arranged between the outer coating and the central metal core, said inner coating containing at least one sodium-based compound and/or at least one potassium based compound. Associated process for welding stainless steel.
Claims21
A coated electrode comprising:
- a central metal core comprising a stainless steel having chromium alloyed with iron;
- an outer coating at least partly surrounding the central metal core, the outer coating comprising rutile and at least one lithium-based compound, wherein the outer coating is essentially free of sodium (Na) feldspar and potassium (K) feldspar;
- and
- at least one inner coating arranged between the outer coating and the central metal core, the inner coating comprising:
- rutile,
- at least one lithium-based aluminosilicate having lithium (Li) in an amount of 0.1 to 1% by weight on the basis of a total weight of the inner coating,
- a lithium silicate, and
- one or both of a sodium-based aluminosilicate and a potassium-based aluminosilicate,
- wherein about 10 to 55% by weight of the total weight of the inner coating is in the form of ferroalloys or of individual elements,
- wherein the outer coating and the inner coating represent between 35% and 42% of the total weight of the electrode.
A method of manufacturing an electrode, the method comprising:
- providing a central metal core comprising a stainless steel having chromium alloyed with iron;
- carrying out a concentric extrusion of an inner coating around at least a part of the central metal core, the inner coating comprising rutile, at least one lithium-based aluminosilicate, a lithium silicate, and one or both of a sodium-based aluminosilicate and a potassium-based aluminosilicate;
- carrying out a concentric extrusion of an outer coating around at least a part of the at least one inner coating, the outer coating comprising rutile and at least one lithium-based compound and being free of sodium feldspar and potassium feldspar;
- and
- baking the central metal core coated with the inner coating and the outer coating in a furnace,
- wherein the outer coating and the inner coating represent between 35% and 42% of the total weight of the electrode, and
- wherein the inner coating comprises:
- lithium (Li) in the at least one lithium-based aluminosilicate present in an amount of 0.1 to 1% by weight on the basis of a total weight of the inner coating, and
- about 10 to 55% by weight of the inner coating is in the form of ferroalloys or of individual elements.
An assembly of a central metal core, an inner coating and an outer coating for an electrode, the central metal core comprising a stainless steel having chromium alloyed with iron, the outer coating covering at least a part of the inner coating, the outer coating comprising rutile and at least one lithium-based compound and being free of sodium feldspar and potassium feldspar, wherein the inner coating comprises rutile, at least one lithium-based aluminosilicate, a lithium silicate, and one or both of a sodium-based aluminosilicate and a potassium-based aluminosilicate, wherein the outer coating and the inner coating represent between 35% and 42% of the total weight of the electrode, and wherein the inner coating comprises:
- lithium (Li) in the at least one lithium-based aluminosilicate present in an amount of 0.1 to 1% by weight on the basis of a total weight of the inner coating;
- and
- about 10 to 55% by weight of the total weight of the inner coating is in the form of ferroalloys or of individual elements.
Dependencies are inferred from the claim text.