Welding flux additive, process for obtaining a welding flux, welding flux and welding process

Abstract

The present invention pertains to the field of metallurgy, materials engineering and nanotechnology. More specifically, the present invention provides a welding flux additive comprising a niobium species, and an improved welding flux, which provides welds with improved mechanical properties. One aspect of the invention consists in enabling the application of the flux onto wire or within tubular wires. The invention also discloses a process for obtaining the welding flux and a welding process.

Description

Welding flux additive, process for obtaining a welding flux, welding flux and welding process. Descriptive Report of Invention Patent Field of Invention

[0001] The present invention is situated in the area of ​​metallurgy, materials engineering and nanotechnology. More specifically, the present invention provides a welding flux additive comprising a niobium species and an improved welding flux, which provides welds with better mechanical properties. One aspect of the invention is to provide the application of the flux to wires or inside tubular wires. The invention also discloses: a process for obtaining the welding flux and a welding process. Background of the Invention

[0002] In the technical field of welding, there are several known techniques for welding different metallic substrates, such as gas-shielded arc welding (active gas or inert gas), submerged arc welding, laser welding, and hybrid laser-arc welding.

[0003] In this context, welding can be done with the aid of a welding flux to improve the properties of the weld. The flux used has a great influence on the properties of the final weld.

[0004] In the search for the state of the art in scientific and patent literature, the following documents were found that address the topic:

[0005] Document WO202284719 discloses the use of a soldering flux complex composed obligatorily of titanate structures (Na2TisO7, NaTiOs, K2TiO3, K2TiO2O5, MgTiOs, SrTiOs, BaTiOs, CaTiOs, FeTiOs and ZnTiO4) with particle sizes less than or equal to 325 mesh (44 micron), niobium nanoparticles and nanoparticles of various oxides that These include: TiO2, SiO2, ZrC, Y2O3, Al2O3, MoOs, CrOs, CeC, La2Os, Nb2Os, NbO, NbÜ2 and mixtures thereof. Additionally, the document discloses the use of complexing agents such as cerium oxide (CeO2), sodium oxide (Na2O), sodium peroxide (Na2O2), sodium bismuthate oxide (NaBiOs), sodium fluoride (NaF), calcium fluoride (CaF2) and sodium hexafluoroaluminum (NasAlFe). Furthermore, the document mentions at least one binder to improve adhesion of pre-coating steel, which is a sol, such as an organofunctional silane (amines, diamines, alkyls, amino-alkyls, epoxy, methacryls, etc.) with an addition of 40 to 400 g / L. The document in question does not disclose a flow as defined in the present invention, which exhibits improved performance when compared to known flows.

[0006] The document entitled “Effect of niobium addition on the flux of submerged arc welding of low carbon steels” published by Osorio et al. (2019), as the title itself reveals, focuses on submerged arc welding, unlike the present invention. Furthermore, it deals with monocrystalline microparticles. Thus, the aforementioned document does not disclose a flux as defined in the present invention, which exhibits improved performance when compared to known fluxes.

[0007] Thus, based on the literature reviewed, no documents were found that anticipated or suggested the teachings of the present invention, so the solution proposed here, in the eyes of the inventors, possesses novelty and inventive activity compared to the state of the art. Summary of the Invention

[0008] The present invention solves the problems of the prior art by incorporating niobium into a welding flux. Said niobium is in the form of particles with a specific granulometry and degree of damping, promoting an increase in the mechanical strength of the weld joint.

[0009] In a first aspect, the present invention presents an additive of Welding flux comprising a mass quantity of niobium species particles, wherein said particles comprise a degree of damping equal to or greater than 19%.

[0010] In one embodiment, the aforementioned mass quantity also exhibits a specific particle size distribution.

[0011] In a second aspect, the present invention provides a process for obtaining a welding flux comprising at least one step of incorporating a welding flux additive comprising niobium species particles into a welding flux, wherein said particles comprise a degree of damping equal to or greater than 19%.

[0012] In a third aspect, the present invention defines a welding flux comprising halogenated inorganic salts and a mass quantity of niobium species particles, wherein said particles have a degree of damping equal to or greater than 19%.

[0013] In a fourth aspect, the present invention provides a welding process comprising at least one step of applying the welding flux, as defined above, to the base metal, wire, or combinations thereof.

[0014] In one embodiment, the base metal in question is steel.

[0015] In a fifth aspect, the present invention provides a material with a welded joint, the joint exhibiting improved mechanical strength.

[0016] These and other objects of the invention will be immediately appreciated by those skilled in the art and will be described in detail below. Brief Description of the Figures

[0017] The following figures are presented:

[0018] Figure 1 shows the welding of sample A done using only wire.

[0019] Figure 2 shows the welding of sample B made with wire and flux without Niobium.

[0020] Figure 3 shows the welding of sample C made with wire and flux with 1% Niobium.

[0021] Figure 4 shows the welding of sample D made with wire and flux containing 5% Niobium.

[0022] Figure 5 shows the welding of sample E made with wire and flux containing 10% niobium.

[0023] Figure 6 shows the welding of sample F made with wire and flux containing 20% ​​Niobium.

[0024] Figure 7 shows a micrograph of sample A made using only wire.

[0025] Figure 8 shows a micrograph of sample B made with wire and flux without Niobium.

[0026] Figure 9 shows a micrograph of sample E made with wire and flux containing 10% niobium nanoparticles.

[0027] Figure 10 shows a micrograph of sample F made with wire and flux containing 20% ​​niobium nanoparticles.

[0028] Figure 11 shows a micrograph of sample C, emphasizing the heat-affected zone (HAZ).

[0029] Figure 12 shows a micrograph of sample D, emphasizing the heat-affected zone (HAZ).

[0030] Figure 13 shows a micrograph of the boundary region of sample C.

[0031] Figure 14 shows a micrograph of the weld region of sample C.

[0032] Figure 15 shows a micrograph of sample D indicating its different phases.

[0033] Figure 16 shows a micrograph of the boundary region of samples C and D.

[0034] Figure 17 shows a micrograph of the white sample, where the highlighted line divides the base material from the welded material.

[0035] Figure 18 shows a micrograph of the flow sample, where the highlighted line divides the base material from the welded material.

[0036] Figure 19 shows a micrograph of the Flux + 1% Nb2Ü5 sample, in which The highlighted line marks the division between the base material and the welded material.

[0037] Figure 20 shows a micrograph of the Flux + 5% Nb2O5 sample, where the highlighted line divides the base material from the welded material.

[0038] Figure 21 shows a micrograph of the Flux + 10% Nb2O5 sample, where the highlighted line divides the base material from the welded material.

[0039] Figure 22 shows a micrograph of the Flux + 20% Nb20s sample, where the highlighted line divides the base material from the welded material.

[0040] Figure 23 shows a micrograph of the welding area of ​​the white sample.

[0041] Figure 24 shows a micrograph of the welding area of ​​the flux sample.

[0042] Figure 25 shows a micrograph of the welding area of ​​the Flux + 1% Nb2O5 sample.

[0043] Figure 26 shows a micrograph of the welding area of ​​the Flux + 5% Nb2O5 sample.

[0044] Figure 27 shows a micrograph of the welding area of ​​the Flux + 10% Nb2O5 sample.

[0045] Figure 28 shows a micrograph of the welding area of ​​the Flux + 20% Nb2O5 sample.

[0046]

[0047] Figure 29 shows a comparative graph of the results of the thermographic analysis of samples A, B, C, D, E, and F during the welding process.

[0048] Figure 30 shows a comparative graph of the results of the thermographic analysis of samples A, B, C, and D during the welding process.

[0049] Figure 31 shows a comparative graph of the results of the thermographic analysis of samples A, B, E, and F during the welding process.

[0050] Figure 32 shows a comparative graph of the results of the thermographic analysis of samples C, D, E, and F.

[0051] Figure 33 shows a comparative graph of the results of the horizontal HV microhardness test for samples A, B, C, D, E, and F.

[0052] Figure 34 shows a comparative graph of the results of the horizontal HV microhardness test for samples C, D, E, and F.

[0053] Figure 35 shows a comparative graph of the results of the horizontal HV microhardness test for samples A, B, E, and F.

[0054] Figure 36 shows a comparative graph of the results of the vertical HV microhardness test for samples A, B, C, D, E, and F.

[0055] Figure 37 shows a comparative graph of the results of the vertical HV microhardness test for samples C, D, E, and F.

[0056] Figure 38 shows a comparative graph of the results of the vertical HV microhardness test for samples A, B, E, and F.

[0057] Figure 39 shows a comparative graph of the results of the vertical HV microhardness test of samples B and C.

[0058] Figure 40 shows the parameters used for preparing the plates subjected to the welding process.

[0059] Figure 41 shows electrodes surrounded by a welding flux.

[0060] Figure 42 shows the welding joint of samples I, II, and III. Sample I was made only with ER70S-3 wire, sample II was made only with wire and flux, and sample III was made only with wire and flux with niobium nanoparticles.

[0061] Figure 43 shows the direction of the indentations in sample I.

[0062] Figure 44 shows the direction of the indentations in samples II and III.

[0063] Figure 45 shows a micrograph of sample I.

[0064] Figure 46 shows a micrograph of sample II.

[0065] Figure 47 shows a micrograph of sample III.

[0066] Figure 48 shows a Vickers microhardness test graph performed on sample I.

[0067] Figure 49 shows a Vickers microhardness test graph performed on sample II.

[0068] Figure 50 shows a Vickers microhardness test graph performed on sample III.

[0069] Figure 51 shows a graph overlaying the results of Vickers microhardness tests performed on samples I, II, and III.

[0070] Figure 52 shows the procedures performed for carrying out the tensile tests on samples A, B, C, D, E and F.

[0071] Figure 53 shows the test specimens produced from samples A, B, C, D, E, and F.

[0072] Figure 54 shows a tensile test graph (stress vs. strain) of sample A (white sample, with wire only), showing strain on the x-axis and stress on the y-axis.

[0073] Figure 55 shows a tensile test graph (stress vs. strain) of samples B (sample with flow without Nb), with strain shown on the x-axis and stress on the y-axis.

[0074] Figure 56 shows a tensile test graph (stress versus strain) of samples C (flow sample containing 1% Nb), with strain shown on the x-axis and stress on the y-axis.

[0075] Figure 57 shows a tensile test graph (stress vs. strain) of samples D (flow sample containing 5% Nb), with strain shown on the x-axis and stress on the y-axis.

[0076] Figure 58 shows a tensile test graph (stress vs. strain) of samples E (flow sample containing 10% Nb), with strain shown on the x-axis and stress on the y-axis.

[0077] Figure 59 shows a tensile test graph (stress versus strain) of samples F (flow sample containing 20% ​​Nb), with strain shown on the x-axis and stress on the y-axis.

[0078] Figure 60 shows a graph comparing the tensile test results of specimens from samples A, B, C, D, E, and F.

[0079] Figure 61 illustrates the difference in the weld regions, the heat-affected zone (HAZ), and the base metal.

[0080] Figure 62 shows a micrograph of the Branca sample.

[0081] Figure 63 shows a micrograph of the sample with polyethylene glycol (PEG).

[0082] Figure 64 shows a micrograph of the sample with PEG and 1% Nb2Ü5.

[0083] Figure 65 shows a micrograph of the sample with PEG and 5% Nb2O5.

[0084] Figure 66 shows a micrograph of the sample with PEG and 10% Nb2O5.

[0085] Figure 67 shows a micrograph of the sample with PEG and 20% Nb2O5.

[0086] Figure 68 illustrates a comparison between micrographs of a sample of PEG and 10% Nb2Os with a sample of PEG, aluminum, and 10% Nb2Os.

[0087] Figure 69 illustrates a comparison between micrographs of a sample of PEG and 20% Nb2Os with a sample of PEG, aluminum, and 20% Nb2Os.

[0088] Figure 70 shows micrographs of the sample with butyl glycol and 30% Nb2Os.

[0089] Figure 71 shows micrographs of the sample with butyl glycol and 70% of Nb2Os.

[0090] Figure 72 shows a micrograph of the sample with molybdenum disulfide (MoS2) and Nb2Os.

[0091] Figure 73 shows a micrograph of the sample with molybdenum disulfide (MoS2) and Nb2Os.

[0092] Figure 74 shows a micrograph of the sample with molybdenum disulfide (MoS2) and Nb2Os.

[0093] Figure 75 shows a micrograph of the sample with molybdenum disulfide (MoS2) and Nb2Os.

[0094] Figure 76 shows a graph comparing Vickers microhardness for the conditions studied. Detailed Description of the Invention

[0095] The following descriptions will provide an intelligible aid to understanding the objects of this patent application.

[0096] The inventive concept common to the various objects of the invention is the incorporation of a welding flux additive containing a type of niobium, in the form of particles of a specific granulometry, into a welding flux. The invention provides an improved welding flow, an improved welding process, and increased mechanical strength of the weld joint.

[0097] In the context of the present invention, the expression "Niobium species" encompasses various chemical entities containing Niobium, including metallic Niobium, oxides, hydrates, hydrides, carbides, or nitrides of Niobium, iron Niobium or Niobium alloyed with other metals or transition metals, or combinations thereof. It also includes Niobium pentoxide (Nb2O5), NbC, NbO, Niobium oxalate, niobic acid, and FeNb. It may be a mass quantity of microparticles, submicroparticles, or nanoparticles.

[0098] In the context of the present invention, the expression "degree of amortization" should be understood as the extent to which a material exhibits a predominantly disordered phase, in contrast to predominantly monocrystalline and polycrystalline phases. "Amortization" can be understood as a process of loss of long-range order of atoms, molecules or ions in the crystalline structure of a given material, and may also exhibit short-range order.

[0099] In a first aspect, the present invention provides a welding flux additive comprising a mass quantity of Niobium species particles, wherein said particles comprise a degree of damping equal to or greater than 19%.

[0100] In one aspect, the present invention provides a welding flux additive comprising a niobium species. In one embodiment of the additive, said niobium species is composed of NbO, NbÜ2, Nb2Ü5, niobic acid, niobium oxalate, FeNb, or combinations thereof.

[0101] In one embodiment of the additive, the aforementioned niobium species is in the form of Nb2Ü5 nanoparticles.

[0102] In one embodiment, the particle size distribution profile of Nb2Ü5 nanoparticles is: d10: between 14 and 110 nm; d50: between 29 and 243 nm; and d90: between 89 and 747 nm.

[0103] In one embodiment of the additive, the aforementioned type of Niobium is a mass quantity of Nb2Ü5 nanoparticles comprising a significant degree of amortization. In one embodiment, said particles have a degree of amortization of at least 19%.

[0104] The welding flux additive of the invention is useful for preparing an improved welding flux.

[0105] In a second aspect, the present invention defines a process for obtaining the welding flux of the invention comprising at least one step of incorporating a welding flux additive comprising niobium species particles into a welding flux, wherein said particles comprise a degree of amortization equal to or greater than 19%.

[0106] The invention provides for the application of flux into wire or inside tubular wires.

[0107] In a third aspect, the present invention defines a welding flux comprising halogenated inorganic salts and a mass quantity of niobium species particles, wherein said particles have a degree of amortization equal to or greater than 19%.

[0108] In one embodiment of the welding flux, said niobium species particles comprise a coating. In one embodiment, said coating comprises polyethylene glycol (PEG), butyl glycol, or combinations thereof.

[0109] In one embodiment of the welding flux, said halogenated inorganic salts are fluxing salts. In one embodiment, said halogenated inorganic salts are selected from LiCl, KCl, NaCl, KAIF4, NaF, ZnCl2 and combinations thereof.

[0110] In one embodiment, the soldering flux comprises an inorganic-organic hybrid paste based on fluxing salts (halide / fluoride) with surface-modified metal oxide nanoparticles.

[0111] In one embodiment, the said welding flux additionally comprises aluminum or molybdenum disulfide.

[0112] In a concrete scenario, the flow comprises between 0.01% and 70% in Niobium species mass. In one embodiment, the flux comprises between 0.01% and 50% by mass of niobium species. In one embodiment, the flux comprises between 0.01% and 30% by mass of niobium species. In one embodiment, the flux comprises between 0.01% and 20% by mass of niobium species. In one embodiment, the flux comprises between 0.01% and 10% by mass of niobium species. In one embodiment, the flux comprises between 0.01% and 5% by mass of niobium species. In one embodiment, the flux comprises between 0.01% and 3% by mass of niobium species. In one embodiment, the flux comprises between 0.01% and 2% by mass of niobium species. In one embodiment, the flux comprises less than 2% by mass of niobium species.

[0113] In one embodiment of the flow, the aforementioned Niobium species is composed of NbO, NbÜ2, Nb2Ü5, niobic acid, niobium oxalate, FeNb, or combinations thereof.

[0114] In one embodiment of the flow, the aforementioned Niobium species is composed of Nb2Ü5 nanoparticles.

[0115] In one embodiment of the flow, the aforementioned Niobium species is a mass quantity of Nb2Ü5 nanoparticles comprising a significant degree of amortization.

[0116] In one embodiment, the aforementioned mass quantity of particles comprises an amortization level of at least 19%.

[0117] In one embodiment, the said mass quantity of particles preferably comprises an amortization rate of at least 20%, more preferably at least 25%, more preferably at least 30%, more preferably at least 35%, more preferably at least 39%, more preferably at least 40%, more preferably at least 45%, more preferably at least 50%, more preferably an amortization rate of at least 55%, more preferably at least 60%, more preferably at least 65%, and even more preferably an amortization rate of at least 70%. In one embodiment, the degree Amortization of at least 71%, more preferably at least 72%, most preferably at least 73%. In a non-limiting embodiment, the amortization rate is 74%.

[0118] In one embodiment, the said mass quantity of particles preferably comprises an amortization rate of at least 39%, preferably an amortization rate of at least 55%, and even more preferably an amortization rate of at least 70%.

[0119] In one embodiment, the flow additionally includes inorganic salts and oxides.

[0120] In another aspect, the present invention provides a welding process comprising at least one step of applying the welding flux, as defined above, to the base metal, wire, electrode, surfaces to be welded, or combinations thereof.

[0121] In one embodiment, the welding process is performed by electric arc welding.

[0122] In one application, the welding process is performed using MAG, MIG, TIG, SAW, or HLAW.

[0123] In one embodiment, the welding process is performed using MAG (active gas) type electric arc welding.

[0124] In one embodiment, the wire (filler metal) used in the MAG welding process contains at least 90% iron (Fe) by mass.

[0125] In one specific application, the wire used could be a welding wire for structural steel, galvanized steel, low-alloy steel, in pipes, boiler construction, and similar applications.

[0126] In another aspect, the present invention provides a material with a welded joint, the joint exhibiting high mechanical strength.

[0127] In one embodiment, the welded joint features an improved heat-affected zone (HAZ).

[0128] The thermally affected zone presents completely different conditions. Distinct from the base metal, the heat-affected zone (HAZ) is largely responsible for causing catastrophes in welded structures, such as in pipe and pressure vessel welds. The present invention provides a heat-affected zone (HAZ) with improved mechanical properties.

[0129] The following examples are intended only to illustrate some of the numerous ways in which the invention can be implemented, without, however, limiting its scope. Example 1: Process for preparing niobium pentoxide nanoparticles.

[0130] A Labstar LS01 stirred ball mill (Netzsch) was fed with micrometric particles of niobium pentoxide. The process involved high-energy wet milling. The particle suspension was 17.7 wt%, consisting of approximately 3500 g of milli-Q water + 10 M NaOH and 750 g of the solid sample, which was prepared and stabilized in the mill's mixing tank at pH 9 and titrated with 10 M NaOH. The milling spheres used were yttria-stabilized zirconia, 400 µm in diameter. The milling chamber was filled to 80% vol. and the suspension temperature was below 40 °C. The mill rotation speed was set to 3000 rpm and milling was conducted for 8 hours. To stabilize the suspension at pH 9, 10 M NaOH was added during milling, with samplings taken periodically and particle sizes measured.

[0131] In this example, several embodiments of niobium pentoxide nanoparticle preparations were obtained, with a purity greater than 99%. Commercial niobium pentoxide, with the particle size distribution described in Table 1, was pre-milled in a high-energy mill containing yttria-stabilized zirconia beads with a diameter of 400 µm, in liquid medium, and the pH adjusted to 6.6. The mill rotation speed was 3500 rpm, and the particle grinding was conducted at a temperature below 40 °C. Table 4 shows the particle size distribution (PSD) of niobium pentoxide. input (commercial product) and output of a pre-comminution stage.

[0132] Table 1 - Input DTP (commercial product) and output DTP after pre-comminution.

[0133] The average specific surface area S (m 2 The mass of the particles after the pre-comminution step was 0.32 m / g. 2 / g.

[0134] In one embodiment, the pre-comminuted particles were then fed into a high-energy mill, where conditions similar to those described above were applied, but with 200 µm Zr spheres and milled for different times, until each nanoparticle preparation was obtained. Three different nanoparticle preparations were obtained, each with a defined particle size distribution as described in Table 2.

[0135] Table 2 - Particle size distribution of three different preparations (C, D and E) of niobium pentoxide nanoparticles.

[0136] Nanometric particles of niobium pentoxide were used, produced as described in patent application BR112023003019-6 filed by Fras-le, which is incorporated herein by reference.

[0137] Without intending to be bound by theory, it is understood that samples subjected to 12 hours of grinding exhibit a higher degree of amortization (74%), and thus contribute at least in part to the surprising effects presented. Example 2: Nanostructured niobium applied in the MAG welding process.

[0138] In this example, thermographic analysis tests were performed and Microhardness tests for weld samples obtained using the MAG technique.

[0139] The materials used in the MAG (active gas) welding process were as follows: argon (75%), carbon dioxide (25%), ER70S-6 wire and IMC welding machine.

[0140] In this experiment, six samples (A, B, C, D, E, F) were prepared for welding: A. Welding using only ER70S-6 wire; B. Welding with welding wire and flux; C. Welding with welding wire and flux comprising 1% by mass of niobium nanoparticles; D. Welding with welding wire and flux comprising 5% by mass of niobium nanoparticles; E. Welding with welding wire and flux comprising 10% by mass of niobium nanoparticles; and F. Welding with welding wire and flux comprising 20% ​​by mass of niobium nanoparticles.

[0141] The results of the welding for each sample A, B, C, D, E, and F are presented in detail in Figures 1 to 6. Aluminex commercial flux was used as a reference.

[0142] Figure 1 shows an example of welding using only ER70S-6 wire, demonstrating good arc stability and a homogeneous weld bead.

[0143] Figure 2 shows an example of welding with wire and flux without niobium pentoxide nanoparticles, demonstrating welding with good arc stability and a homogeneous weld bead.

[0144] Figure 3 shows an example of welding with wire and flux containing 1% niobium pentoxide nanoparticles, demonstrating welding with good arc stability and a homogeneous weld bead.

[0145] Figure 4 shows an example of welding with wire and flux containing 5% niobium pentoxide nanoparticles, demonstrating good welding performance. Arch and cord instability with homogeneity

[0146] Figure 5 shows an example of welding with wire and flux containing 10% niobium pentoxide nanoparticles, demonstrating welding with good arc stability and a homogeneous weld bead.

[0147] Figure 6 shows an example of welding with wire and flux containing 20% ​​niobium pentoxide nanoparticles, demonstrating welding with good arc stability and a homogeneous weld bead.

[0148] Figure 7 shows a micrograph of sample A made using only wire.

[0149] Figure 8 shows a micrograph of sample B made with wire and flux without Niobium.

[0150] Figure 9 shows a micrograph of sample E made with wire and flux containing 10% niobium nanoparticles.

[0151] Figure 10 shows a micrograph of sample F made with wire and flux containing 20% ​​niobium nanoparticles.

[0152] Figure 11 shows a micrograph of sample C, emphasizing the heat-affected zone (HAZ).

[0153] Figure 12 shows a micrograph of sample D, emphasizing the heat-affected zone (HAZ).

[0154] Figure 13 shows a micrograph of the boundary region of sample C.

[0155] Figure 14 shows a micrograph of the weld region of sample C.

[0156] Figure 15 shows a micrograph of sample D indicating its different phases.

[0157] Figure 16 shows a micrograph of the boundary region of samples C and D.

[0158] In cases B, C, D, E, and F, there was no interference in the welding process with the application of the flux paste. Example 3: Addition of Nb2U5 to the welding area using commercial flux as a conductive medium.

[0159] A paste with commercial flux and the addition of Nb2Ü5 was developed. The sample called "White" has no added paste, while the sample called "Flow" contains a commercial flux; the other pastes contain additions of niobium pentoxide nanoparticles. • White Sample; • Sample Flow; • Sample Flow + 1% Nb2Ü5; • Sample Flow + 5% Nb2O5; • Sample Flow + 10% Nb2Ü5; • Sample Flow + 20% Nb2U5.

[0160] In figures 17, 18, 19, 20, 21 and 22, the highlighted red line divides the base material from the welded material for the samples described above.

[0161] Figures 23, 24, 25, 26, 27 and 28 refer to the welding area for the samples described above.

[0162] The results of the thermographic analysis of each sample are presented in detail in figures 29 to 32. Table 3: results of the thermographic analysis

[0163] Thermographic analysis shows that the flow containing niobium nanoparticles exhibits a significant difference in the temperature profile of the weld pool.

[0164] The results of the microhardness tests for each sample are presented in detail in Figures 33 to 39. Example 4: Analysis of improvements in the heat-affected zone (ZTA) with the addition of Nb20s

[0165] In this example, the materials and methodology involved the use of ER70S-3 wire with a thickness of 3.2 mm, a welding current of 160 A, a 45° root weld, and 1020 carbon steel as the base material.

[0166] Three samples (I, II, III) were prepared: I. Wire welding II. Welding with wire and flux III. Welding with wire and flux comprising Nb2U5.

[0167] Figure 40 shows the parameters used for preparing the plates subjected to the welding process.

[0168] Figure 41 shows electrodes surrounded by a welding flux.

[0169] Figure 42 shows the welding joint of samples I, II, and III. Sample I was made only with ER70S-3 wire, sample II was made only with wire and flux, and sample III was made only with wire and flux with niobium nanoparticles.

[0170] Figure 43 shows the direction of the indentations in sample I.

[0171] Figure 44 shows the direction of the indentations in samples II and III.

[0172] Figure 45 shows a micrograph of sample I.

[0173] Figure 46 shows a micrograph of sample II.

[0174] Figure 47 shows a micrograph of sample III.

[0175] The results of the Vickers microhardness test performed on each of samples I, II, and III are presented in greater detail in Figures 48 to 50, respectively.

[0176] Figure 51 shows a graph overlaying the results of Vickers microhardness tests performed on samples I, II, and III.

[0177] An increase in mechanical strength was observed in the microhardness test with a flux containing niobium nanoparticles. Additionally, an improvement in the HAZ (Heat Affected Zone) was observed. For comparison, a hardness of 741 HV becomes approximately 61 HRC, similar to a surface treatment. Example 5: Tensile tests on samples A, B, C, D, E, and F.

[0178] This example shows tensile tests. The methodology used to perform the tensile test is presented in greater detail in Figure 52.

[0179] Figure 53 shows the test specimens produced from samples A, B, C, D, E, and F.

[0180] The test was performed in triplicate for each sample from A to F, so the test included 18 specimens. Three specimens for each sample from A to F. F were provided so that the test could be performed in triplicate.

[0181] Figure 54 shows a tensile test graph (stress versus strain) of samples A.

[0182] Figure 55 shows a tensile test graph (stress versus strain) of samples B.

[0183] Figure 56 shows a tensile test graph (stress versus strain) of samples C.

[0184] Figure 57 shows a tensile test graph (stress versus strain) of samples D.

[0185] Figure 58 shows a tensile test graph (stress versus strain) of samples E.

[0186] Figure 59 shows a tensile test graph (stress versus strain) of samples F.

[0187] The results of the tensile test (stress MPa versus strain s) performed on the specimens for each of the samples A, B, C, D, E, and F are compared in Figure 60. Table 4: Results for the tensile test of samples A to F Example 6: Sample tests with the addition of Nb2Ü5 and polyethylene glycol

[0188] Samples were prepared using niobium pentoxide coated with polyethylene glycol (PEG) 6000. • White Sample; • PEG sample; • PEG sample + 1% Nb2Ü5; • PEG sample + 5% Nb2O5; • PEG sample + 10% Nb2Ü5; • Sample PEG + 20% Nb2U5.

[0189] Figure 61 illustrates the difference in the weld regions, the heat-affected zone (HAZ), and the base metal.

[0190] Figure 62 shows a micrograph of the Branca sample.

[0191] Figure 63 shows a micrograph of the sample with PEG.

[0192] Figure 64 shows a micrograph of the sample with PEG and 1% Nb2Ü5.

[0193] Figure 65 shows a micrograph of the sample with PEG and 5% Nb2Ü5.

[0194] Figure 66 shows a micrograph of the sample with PEG and 10% Nb2O5.

[0195] Figure 67 shows a micrograph of the sample with PEG and 20% Nb2O5.

[0196] As can be seen from the micrographs above, the appearance of inclusions in the samples with the paste containing Nb2Ü5 and PEG 6000 is noticeable.

[0197] Therefore, a concentration of aluminum was added to the paste, which helps stabilize the weld pool, thus reducing the amount of porosity.

[0198] Figure 68 illustrates a comparison between micrographs of a sample of PEG and 10% Nb2Ü5 with a sample of PEG, aluminum and 10% Nb2Ü5.

[0199] Figure 69 illustrates a comparison between micrographs of a sample of PEG and 20% Nb2Ü5 with a sample of PEG, aluminum and 20% Nb2Ü5.

[0200] The micrographs cited above prove that aluminum helped stabilize the weld pool, reducing the amount of pores. Example 7: Sample tests with the addition of Nb2Os and butyl glycol

[0201] Next, samples were prepared using niobium pentoxide coated with butyl glycol. • Sample: butyl glycol + 30% Nb20s; • Sample: butyl glycol + 70% Nb2O5.

[0202] Figure 70 shows micrographs of the sample with butyl glycol and 30% Nb2O5.

[0203] Figure 71 shows micrographs of the sample with butyl glycol and 70% Nb2O5. Example 8: Sample tests with molybdenum disulfide with the addition of Nb2Os

[0204] Next, samples were prepared using molybdenum disulfide paste.

[0205] Figures 72, 73, 74 and 75 show a micrograph of the sample with molybdenum disulfide (MoS2) and Nb2O5.

[0206] Finally, Figure 76 compares the Vickers microhardness for the conditions studied.

[0207] Without desiring to be bound by theory, the combination of materials in the present invention created a surface mechanism that refined the structure and produced microspheres with grain control and refined structure, that is, generating Spheroidization from welding (instead of the more common cooking method).

[0208] Those skilled in the art will appreciate the knowledge presented here and will be able to reproduce the invention in the forms presented and in other variants and alternatives, covered by the scope of the following claims.

Claims

Claims 1. Welding flux additive characterized by comprising a mass quantity of niobium particles, wherein said particles comprise a degree of amortization equal to or greater than 19%.

2. Additive according to claim 1 characterized in that said niobium species is selected from NbO, NbC, Nb2O5, niobic acid, niobium oxalate, FeNb or combinations thereof.

3. Additive according to claim 2 characterized in that said niobium species is composed of Nb2Ü5 nanoparticles.

4. Process for obtaining a welding flux characterized by comprising at least one step of incorporating a welding flux additive comprising niobium particles into a welding flux, wherein said particles comprise a degree of damping equal to or greater than 19%.

5. Welding flux characterized by comprising halogenated inorganic salts and a mass quantity of niobium particles, wherein said particles have a degree of damping equal to or greater than 19%.

6. Welding flux according to claim 5 characterized in that niobium species particles comprise a coating.

7. Welding flux according to claim 5 characterized in that said halogenated inorganic salts are selected from LiCl, KCl, NaCl, KAIF4, NaF, ZnCl2 and combinations thereof.

8. Welding flux according to claim 6, characterized by further comprising aluminum or molybdenum disulfide.

9. Welding flux according to claim 5 characterized by comprising between 0.01% and 70% by mass of niobium species.

10. Welding process characterized by comprising at least one step of applying welding flux, as defined in any one of claims 5 to 9, in the base metal, wire, electrode, surfaces to be welded or combinations thereof.

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