JP3210609U - Consumable electrode for special coated metal - Google Patents

Abstract

A consumable electrode for use in arc welding operations and a system for welding including the consumable electrode. A consumable electrode for use in arc welding on a workpiece having a zinc coating includes a metal sheath that surrounds a core and filler material is disposed within the core. The filler material includes a fluxing material 140, which facilitates the separation of the workpiece coating into at least partially formed slag. The fluxing material comprises 2-6% by weight of the electrode of deoxygenated material. The oxygen scavenging material includes aluminum and / or magnesium. In order to reduce fume formation, the concentration of the slag forming material in the core is separated from the weld / slag interface to create a weld that is slightly porous or has no porosity at all. Limited to the concentration required to separate enough zinc. [Selection] Figure 2

Description

  Particular embodiments relate to a consumable electrode used in arc welding operations. In particular, particular embodiments include gas-shield metal arc welding (GMAW) or gas-shield flux core arc welding (FCAW-G) on workpieces having metal coatings. The present invention relates to a low fume consumable electrode having porosity resistance used in the construction of the present invention. More particularly, the present invention relates to a consumable electrode for use in arc welding operations involving workpieces having a zinc coating, according to each of the consumable electrodes according to claim 1, 12 and 14, for welding including a consumable electrode. And the use of consumable electrodes.

  Metals such as iron or steel can be galvanized, such as coated with zinc. The zinc coating prevents corrosion of the underlying iron or steel by forming a physical barrier. In addition, zinc can act as a sacrificial anode to protect iron or steel even when obstacles are peeled off or damaged. Although galvanized steel can be welded, galvanization creates a number of problems. In addition to the generation of zinc oxide fume, the zinc coating can create volatile materials or oxides that adversely affect the quality of the weld. For example, zinc vapor can be trapped in the weld paddle, leading to high porosity in the final weld. This occurs when the weld paddle cools before steam leaks, when there is no path for steam leaks, and / or when high concentrations of zinc volatiles are present. In addition, zinc volatiles and zinc oxide interfere with the arc, produce high spatter, and cause unstable welding. Because of these problems, galvanized workpieces are periodically pretreated by removing the zinc coating, eg, by grinding, before performing the main welding operation. However, pre-processing workpieces prior to welding is time consuming and inefficient. Therefore, rather than removing the coating first, it is a recent trend to weld the coating. However, this method can cause significant spatter that can cause problems when the workpiece is later applied and / or cause internal porosity that can lead to poor mechanical properties (fatigue life). Will result in welding.

  Through comparison of such an approach with the embodiments of the invention specified herein below with reference to the drawings, further limitations and disadvantages of the conventional, typical and proposed approach are It will be apparent to those skilled in the art.

  Embodiments of the present invention are consumable electrodes for use in arc welding, such as gas shielded arc welding (GMAW) or gas shielded flux core arc welding (FCAW-G) applications on workpieces having metal coatings such as zinc coatings. including. Such application can include any brazing, cladding, building up, filling, curing, overlaying, joining and welding applications. The electrode includes a metal sheath that surrounds the core, and filler material is disposed within the core. The filler material can include, for example, iron in the range of 8% to 12% by weight of the electrode. Of course, in addition to the iron in the filler material, the metal sheath can also contain iron. For example, the metal sheath may be 100% iron. The filler material further includes fluxing materials, which facilitate partitioning of the workpiece coating to a slag that is at least partially formed by the fluxing material. The fluxing material includes a deoxygenating material in the range of 2% to 6% by weight of the electrode. The oxygen scavenging material can include aluminum and / or magnesium. In order to reduce fume formation, the concentration of the slag forming material in the core should be sufficient away from the weld / slag interface to create a weld that is slightly porous or not porous at all. The concentration required to separate the coated metal is limited. Further embodiments and advantages of the invention can be inferred from the description, drawings and claims.

  These and / or other features of the claimed invention will be more fully understood from the following description and drawings, as well as the details of the illustrated embodiments of the invention.

These and / or other features of the present invention will become more apparent from the detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings.
1 is a functional schematic block diagram of an exemplary system for GMAW or FCAW-G construction according to the present invention. FIG. 2 is an exemplary embodiment of a consumable electrode that may be used in the system of FIG. FIG. 3 is an exemplary cross-sectional view of a weld / slag interface created by the system of FIG. 1 using the consumable electrode of FIG.

  Exemplary embodiments of the present invention are described below with reference to the accompanying figures. The illustrative embodiments described are intended to assist in understanding the present invention and are not intended to limit the scope of the present invention in any way. Like reference numerals refer to like elements throughout.

  FIG. 1 illustrates a functional schematic block diagram of an exemplary system for GMAW or FCAW-G installation. While the present invention is described in terms of a consumable electrode for use in GMAW / FCAW-G construction, the present invention can be used in other types of processes. The system includes a welding power source 80. Although an alternating current (AC) or other type of power supply is possible, the power supply 80 is a pulsed direct current (DC) power supply. The configuration of the power supply 80 is well known in the art and will not be discussed further for the sake of brevity.

  The power source 80 is operatively connected to the contact tube 20 housed in the torch 10. The contact tube 20 makes contact with the consumable electrode 40. The power supply 80 can include an arc initiation circuit (not shown) to generate the arc 30 between the consumable electrode 40 and the workpiece 50. Once the arc 30 is formed, the power source 80 provides current through the contact tube 20, the consumable electrode 40, and the arc 30 to heat the workpiece 50 and form the weld paddle 45. During operation, the arc 30 melts the consumable electrode 40, which provides filler material for joining, welding, brazing, cladding, and the like. The wire supply system supplies the consumable electrode 40 toward the workpiece 50 when the electrode 40 is depleted. The workpiece 50 also has a zinc coating 52 that is melted or vaporized by the arc 30 during the heating process. The gas supply 60 provides a shielding gas to the torch 10 to help reduce porosity in the final weld layer due to nitrogen and oxygen in the air. The shield gas displaces air and forms a shield around the arc 30 and the weld paddle 45. As discussed further below, the interaction of filler material in consumable electrode 40 with coating 52 and workpiece 50 during the welding process creates weld / slag layer 54.

  As discussed above, the zinc coating 52 is problematic in that it creates porosity in the final weld. In order to solve this problem, the present invention provides a low-fume consumable electrode 100 having porosity, as illustrated in FIG. The consumable electrode 100 is designed for a coated metal such as, for example, a zinc-galvanized steel. In an exemplary embodiment of the present invention, the consumable electrode 100 may be a cored filler wire having a steel sheath 110. The sheath 110 surrounds the core 120 having the iron powder 130, the fluxing material 140 and the alloying agent 150. In some exemplary embodiments, the consumable electrode 100 may be a flux-cored filler wire. In another exemplary embodiment, electrode 100 is a metal cored filler wire. In an exemplary embodiment of the invention, the electrode 100 may be specially designed for use with a shielding gas when welding. In yet another embodiment, the consumable electrode 100 is designed to be used in a DC Current Electrode Negative (DCEN) mode configuration.

  In an exemplary embodiment of the present invention, the sheath 110 may be made of low carbon steel having 0.05 wt% to 0.1 wt% carbon of the sheath 110. With respect to the filler material in the core 120, the main component of the core is iron 130. The filling rate of the iron 130 in the core 120 is in the range of 49 wt% to 80 wt% of the core 120. The core also contains fluxing material 140. As will be discussed further below, fluxing material 140 is included to at least create slag, which may help remove zinc and / or prevent nitrogen from entering the weld paddle. The fluxing material 140 can include a metal fluoride (or acidic oxide) and a deoxygenated metal. In some exemplary embodiments of the present invention, the fluoride may be, for example, barium fluoride, calcium fluoride, and / or strontium fluoride. Of course, the present invention is not limited to these fluorides, but may include other fluorides as long as it promotes the formation of slag. In some embodiments, the oxygen scavenging material can be magnesium and / or aluminum. The present invention is not limited to these oxygen scavengers, but can include other oxygen scavengers as long as it promotes the separation of zinc in the slag as discussed below. Based on the welding process and desired welding characteristics, the electrode 100 may also contain an alloying agent 150 such as carbon, manganese, silicon, titanium, chromium, nickel, boron, molybdenum, zirconium, calcium and / or barium. Of course, the alloy agent 150 is not limited to the above-described elements and compounds, but may include other alloy agents based on desired welding characteristics.

  As discussed above, a significant concern when welding galvanized metal is porosity due to trapped zinc vapor. However, when the filler wire is moved to the weld paddle, the porosity can also be caused by nitrogen in the air trapped in the weld paddle. In this regard, the metal fluoride (or acid oxide) and deoxygenated metal discussed above can help prevent nitrogen and oxygen in the air from coming into contact with the weld paddle. During the welding process, fluoride and oxygen scavenger are released from the consumable electrode 100 to help form slag. Slag is rich in oxide and will form as aluminum, magnesium, and other materials that react with oxygen in the air. The slag cools and solidifies before the weld paddle and floats on top of the weld paddle. The slag then functions as an obstacle to help prevent nitrogen and oxygen in the air from entering the weld paddle 45.

  Further, in the present invention, the slag also helps remove zinc volatiles and zinc oxide formed from the welding paddle 45 during the welding process. As illustrated in FIG. 3, when welding galvanized steel, a two-phase slag layer 310/320 is formed on top of the weld layer 300. At the weld / slag interface 305, aluminum oxide and / or magnesium oxide forms a relatively dense slag layer 310. A second slag layer 320 having a lower density and made mostly of zinc oxide is formed on top of the high density slag layer 310. That is, the zinc separates away from the weld / slag interface 305 and becomes a more porous portion of the slag. Zinc separation is similar to the desulfurization process in steelmaking. In that process, the fluxing additive increases the sulfur capacity of the slag and thus reduces the sulfur trapped in the steel. Similarly, aluminum and magnesium are used to reduce the zinc trapped within the weld paddle 45 by separating the zinc away from the weld / slag interface 305. In this case, the weld / slag interface 305 would be mostly oxides rich in aluminum and / or magnesium.

Oxides that are used to create slag, while acting as an obstacle to nitrogen and oxygen in the air and separating zinc from the weld, while the slag has a beneficial effect; Some of the fluorides and oxidants form fumes. For example, fluorides such as calcium fluoride, barium fluoride and strontium fluoride and oxygen scavengers such as magnesium create significant slag and produce fumes. In addition, since the slag must be removed from the final weld, too much slag can make the manufacturing process inefficient. Thus, in an exemplary embodiment of the present invention, the concentration of the material forming the slag in the core 120 may be slightly porous, or may not be completely porous, in order to reduce fume and slag formation. To create a weld 300 that does not have, it is limited to a concentration that requires separation of sufficient zinc away from the weld / slag interface 305. Such welds can achieve tensile strengths in the range of 450 MPa to 900 MPa. In an exemplary embodiment of the invention, the fluoride in the consumable electrode 100 may range from 0% to 2.2% by weight of the electrode 100. In some embodiments, the fluoride ranges from 0.43% to 0.52% by weight of electrode 100. In an exemplary embodiment of the invention, the oxygen scavenger may range from 2% to 6% by weight of electrode 100, and in some embodiments, the oxygen scavenger is 4.15% by weight of electrode 100. It may be in the range of -5.03 wt%. Further, in exemplary embodiments of the present invention, the carbon in the filler material may range from 0% to 0.5% by weight of the electrode 100, and in some embodiments, the carbon is about about 100% of the electrode 100. 0.003% by weight. In some exemplary embodiments, the consumable electrode 100 can have a fill material as shown in Table 1.

  The first column of Table 1 is an exemplary list of filler materials that can be used in electrodes consistent with the present invention. Of course, other materials may be used without departing from the spirit of the present invention. The next two columns show the minimum and maximum weight percentage of the wire (electrode) of each filler material. Not all listed materials need necessarily be present in all embodiments of the present invention, such as those represented by 0% by weight in the Minimum Weight% column. However, in some exemplary embodiments of the present invention, the filler material combination accounts for about 15.5% by weight of the electrode 100. In the exemplary embodiment disclosed in Table 1, the last two columns show the minimum and maximum weight percentage of each filler material as a percentage of the total filler material weight.

Table 2 shows chemicals for an exemplary embodiment of electrode 100. The column “Fill” indicates the weight percentage of the total fill material relative to the fill material that accounts for about 15.5 wt% of the electrode 100. The next two columns show the variation (ie, minimum weight percentage and maximum weight percentage) as the weight percentage of the wire (electrode) of each filler material in the exemplary embodiment of the present invention. Thus, the filler material in these embodiments may range from about 14% to about 17% by weight.

  In an exemplary embodiment of the invention, the consumable electrode 100 may be used in a GMAW system or an FCAW-G system, such as that illustrated in FIG. The classification of whether the electrode 100 is a metal cored electrode or a flux cored electrode is determined by the amount of the flux material 140 in the core 120.

  In the above embodiment, the electrode 100 is designed for reduced slag formation. Therefore, in some applications there is a greater risk that nitrogen in the air will be transferred to the weld paddle 45 and thus there may be a greater risk of weld bead porosity. Thus, consistent with the present invention, the consumable electrode 100 can be designed to be used with a shielding gas as illustrated in FIG. 1 to provide additional porous protection. The shielding gas replaces nitrogen and oxygen in the air by forming an envelope around the arc 30 and the weld paddle 45. The shielding gas may be argon, helium, carbon dioxide, or any other inert gas or any mixture thereof. For example, the shielding gas may be a combination of carbon dioxide and argon, in which the concentration range of carbon dioxide ranges from 10% to 25%.

  In some exemplary embodiments, the GMAW or FCAW-G system may be set as a direct current electrode negative (DCEN) mode. In the direct current electrode positive (DCEP) mode, there is a high penetration of the workpiece that results in a “keyhole effect”. Thus, there is an increased interaction with the zinc coating at the root of the weld using the DCEP method. By using the DCEN method, there is minimal penetration, ie there is no keyhole effect, but the weld strength is not compromised. Since there is no keyhole effect, the interaction with the zinc coating is reduced and the risk of porosity is low.

  By limiting slag and fume as discussed above, exemplary embodiments of the present invention can provide stable welds on galvanized metal, for example, 40 in / min (in / It is possible to produce at a moving speed faster than minute). In addition, welds formed with consumable electrodes consistent with the present invention can achieve a tension greater than 700 MPa, which is comparable to a high strength automotive sheet metal.

  Although the present invention has been described with reference to particular embodiments, it will be understood by those skilled in the art that various modifications can be made and equivalents can be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope of the invention. Accordingly, it is intended that the invention be disclosed and not limited to specific embodiments, but include all embodiments falling within the scope of the appended claims.

10 Torch 20 Contact tube 30 Arc 40 Electrode 45 Weld paddle 50 Work piece 52 Zinc coating 54 Welding / slag layer 60 Gas supply 80 Power supply 100 Electrode 110 Steel sheath 120 Core 130 Iron powder 140 Fluxing material 150 Alloy agent 300 Weld layer 305 Weld / Slag interface 310 Slag layer 320 Slag layer

Claims (14)

A consumable electrode for use in arc welding construction involving a workpiece having a zinc coating,
A metal sheath surrounding the core;
A filler material disposed within the core and including a fluxing material;
Including
The fluxing material promotes the fluxing material to at least partially separate the zinc coating of the workpiece to form a slag;
The fluxing material comprises a deoxygenating material in the range of 2% to 6% by weight of the consumable electrode;
Consumable electrode.   2. The filler material of claim 1, further comprising: 2.2 wt% or less of fluoride, 0.5 wt% or less of carbon, and 0.1 wt% or less of barium of the consumable electrode. Consumable electrode.   The consumable electrode according to claim 2, wherein the fluoride includes 1.5 wt% or less of barium fluoride and 0.04 wt% or less of strontium fluoride of the consumable electrode.   The consumable electrode according to any one of claims 1 to 3, wherein the deoxidizing material includes aluminum in the range of 2 wt% to 5 wt% of the consumable electrode and magnesium of 1 wt% or less. .   The filler material may include up to 0.1 wt% calcium, up to 1.2 wt% manganese, silicon in the range of 0.1 wt% to 0.3 wt%, and up to 0. 5. The consumable electrode according to any one of claims 1-4, further comprising 03 wt% titanium, up to 0.04 wt% aluminum oxide, and up to about 0.01 wt% silicon oxide.   The consumable electrode according to claim 4, wherein the aluminum is in the range of 3.78 wt% to 4.59 wt%, and the magnesium is in the range of 0.37 wt% to 0.44 wt%.   The consumable electrode according to claim 2, wherein the barium is in the range of 0.04 wt% to 0.05 wt%, and the carbon is 0.003% wt.   The calcium is in the range of 0.05 wt% to 0.06 wt%, the manganese is in the range of 0.02 wt% to 0.03 wt%, and the silicon is 0.19 wt% to 0.23 wt%. The consumable electrode according to claim 5, wherein the consumable electrode is in the range of wt%, the titanium is 0.002 wt%, the aluminum oxide is 0.02 wt%, and the silicon oxide is 0.01 wt%. .   4. The consumable electrode according to claim 2, wherein the fluoride includes 1.5 wt% or less of barium fluoride and 0.3 wt% or less of calcium fluoride of the consumable electrode. The filler material further comprises iron in the range of 9.09% to 11.04% by weight of the consumable electrode;
The consumable electrode according to any one of claims 6 to 8, wherein the filler material is in a range of 14 wt% to 17 wt% of the consumable electrode.   The consumable electrode according to any one of the preceding claims, wherein the consumable electrode is designed for use in gas shield applications. A system for use in arc welding construction involving a workpiece having a zinc coating, the system comprising:
A welding power source operably connected to a consumable electrode to generate an arc between the consumable electrode and the workpiece;
A wire feeder system for supplying the consumable electrode to the workpiece;
Including
The consumable electrode is the consumable electrode according to any one of claims 1 to 11.
system. A shielding gas system for providing shielding gas to the consumable electrode and the arc;
The system of claim 12, wherein the welding power source is configured for direct current electrode negative mode configuration.   12. A method as claimed in any preceding claim used to facilitate separation of the workpiece coating into slag during workpiece welding and thus reduce the resulting weld porosity. Consumable electrode as described in.

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