A reduced ilmenite-based titanium type flux-cored wire and a method for manufacturing the same

Abstract

The present application relates to a kind of titanium type flux-cored wire based on reduced ilmenite, which is composed of sheath and core, the core includes the following raw materials: reduced ilmenite, alloying agent, slagging agent, deoxidizer, fluoride, iron powder;And the amount of each material meets the following relationship: ∑Mn / ∑Si=3-5, ∑Mn+∑Si / ∑FeO=5-7;∑Mn, ∑Si, ∑FeO respectively represent the total mass of Mn, Si, FeO in material.The present application uses low-cost reduced ilmenite as the main raw material, through the reasonable matching of other accessories, controls the proportion of each material, especially the proportion between Mn, Si and FeO, and the proportion control of two components of slagging agent, finally obtains the welding performance excellent, high toughness, and has low temperature impact toughness close to the welding wire made of rutile.

Description

Technical Field

[0001] This invention belongs to the field of welding wire technology, specifically relating to a titanium-type flux-cored welding wire based on reduced ilmenite and its preparation method. Background Technology

[0002] Titanium-cored welding wire is a high-efficiency welding material with excellent all-position welding performance and superior comprehensive mechanical properties. It is widely used in shipbuilding, bridge construction, engineering machinery, petrochemicals, and steel structure manufacturing industries. Currently, the TiO2 slagging agent in titanium-cored welding wire is primarily natural rutile with a purity of over 90%. Global natural rutile resources are scarce, with only a few countries such as Australia and South Africa producing it. With the gradual depletion of high-grade natural rutile through annual mining, its price has skyrocketed, severely impacting the manufacturing cost of titanium-cored welding wire.

[0003] Reduced ilmenite has traditionally been used primarily in the coating of ilmenite-type welding electrodes. Due to its high impurity content, it is rarely used in existing technologies for titanium-type flux-cored welding wires, which have high requirements for welding processes.

[0004] Chinese invention patent CN 103358049A discloses "a flux-cored welding wire prepared using high-titanium slag as the main raw material," which reduces the cost of the flux core by replacing rutile with high-titanium slag. The purity of TiO2 in high-titanium slag is close to that of natural rutile, while the content of impurities such as Fe, S, and P is slightly higher. Therefore, high-titanium slag can achieve better overall performance when replacing natural rutile. The price of high-titanium slag is lower than that of natural rutile, but much higher than that of reduced ilmenite.

[0005] Chinese invention patent CN 102328156 A discloses "a reduced ilmenite type flux-cored wire". This patent reduces the cost of flux by partially replacing rutile with reduced ilmenite, but a certain amount of rutile is still required and it cannot be completely replaced by reduced ilmenite. Moreover, the purity of TiO2 and the impurity content of FeO in the reduced ilmenite are not clearly defined, and the slag-forming agent, alloying agent, deoxidizer and other components used in combination are not properly matched. As a result, the impact toughness at -20℃ is below 80J, which barely meets the national standard, but is far lower than the mechanical properties of rutile slag systems.

[0006] Therefore, developing a type of high-quality titanium-type flux-cored welding wire prepared from low-cost raw materials such as reduced ilmenite is of great scientific and industrial significance. Summary of the Invention

[0007] To address the shortcomings of existing titanium-type flux-cored welding wires made from reduced ilmenite, this invention aims to develop a titanium-type flux-cored welding wire using reduced ilmenite as the main raw material. Reduced ilmenite is obtained by high-temperature sintering of ilmenite. my country has abundant and inexpensive ilmenite resources. The price of reduced ilmenite is approximately one-third that of natural rutile and half that of high-titanium slag. Therefore, the reduced ilmenite used as the main raw material for the titanium-type flux-cored welding wire of this invention offers a significant cost advantage. Furthermore, the titanium-type flux-cored welding wire based on reduced ilmenite of this invention exhibits significantly improved low-temperature impact toughness.

[0008] The present invention solves the above-mentioned technical problems through the following technical solutions:

[0009] A titanium-type flux-cored welding wire based on reduced ilmenite, consisting of an outer sheath and a flux core, wherein the flux core comprises the following raw materials: reduced ilmenite, alloying agent, slag-forming agent, deoxidizer, fluoride, and iron powder; and the amounts of each material satisfy the following relationships: ∑Mn / ∑Si=3-5, ∑Mn+∑Si / ∑FeO=5-7; ∑Mn, ∑Si, and ∑FeO represent the total mass of Mn, Si, and FeO in the material, respectively.

[0010] Furthermore, the Mn content in the raw material is 10-17 wt%, preferably 13-15 wt%. For example, 13.5 wt%, 14.2 wt%, or 14.8 wt%.

[0011] Furthermore, ∑Mn / ∑Si=3.2-4.5, ∑Mn+∑Si / ∑FeO=5.5-6.8. By controlling the proportion of raw materials, the total mass of Mn, Si, and FeO can be controlled.

[0012] Further, the reduced ilmenite contains TiO2 ≥ 58 wt% and FeO ≤ 5.5 wt%; preferably, the reduced ilmenite contains TiO2 ≥ 60 wt% and FeO ≤ 5.0 wt%.

[0013] In the YB / T 5141-1993 standard "Reduced Ilmenite Powder for Welding Electrodes," the inventors of two grades, FTH7.20 (TiO2 ≥ 54%, FeO ≤ 7.0%) and FTH9.20 (TiO2 ≥ 52%, FeO ≤ 9.0%), discovered that the high FeO content in the reduced ilmenite powder, according to the YB / T 5141-1993 standard, is detrimental to welding process performance and mechanical properties when used in welding wires. The inventors selected reduced ilmenite with TiO2 ≥ 58wt% and FeO ≤ 5.5wt%, controlling the FeO content and maintaining a suitable ratio of Mn, Si, and FeO, which improved the welding wire performance, particularly its low-temperature impact toughness.

[0014] This invention uses low-cost reduced ilmenite as the main raw material, clearly defines the various chemical composition indicators of reduced ilmenite, especially the relationship between the total Mn, FeO and Si in the material, and through reasonable compatibility with specific slagging agents and fluorides, the resulting titanium-type flux-cored welding wire has high quality. Its welding process performance and post-weld mechanical properties have reached the level of titanium-type flux-cored welding wire made of rutile, and it has excellent all-position welding performance, crack resistance and low-temperature impact toughness.

[0015] Furthermore, the core comprises the following raw materials in parts by weight: 40-70 parts reduced ilmenite, 15-30 parts alloying agent, 5-10 parts slag-forming agent, 1-5 parts deoxidizer, 1-5 parts fluoride, and 1-30 parts iron powder.

[0016] Furthermore, the core comprises the following raw materials in parts by weight: 46-65 parts reduced ilmenite, 20-25 parts alloying agent, 5-10 parts slag-forming agent, 3-5 parts deoxidizer, 1-3 parts fluoride, and 1-30 parts iron powder.

[0017] Furthermore, the alloying agent is at least two of the following: silicon-manganese alloy, silicon-iron alloy, electrolytic manganese, ferrotitanium, ferroboron, and ferrotitanium boron, and satisfies the requirements for ∑Mn+∑Si / ∑FeO and ∑Mn / ∑Si in the above materials.

[0018] Furthermore, the slag-forming agent is a compound of component A and component B, where component A is selected from at least one of zircon sand, quartz sand, and feldspar; and component B is selected from at least one of potassium titanate and sodium titanate. Even further, the slag-forming agent is prepared with component A and component B in a mass ratio of 0.5-2:1, preferably 0.9-1.6:1. The strength of the slag-forming agent prepared according to the above compound is improved.

[0019] Furthermore, the deoxidizer is at least one of magnesium powder and aluminum-magnesium alloy powder; the fluoride is at least one of sodium fluoride, sodium fluorosilicate, and potassium fluorosilicate.

[0020] The present invention also provides a method for preparing the above-mentioned titanium-type flux-cored welding wire based on reduced ilmenite, comprising the following steps:

[0021] The outer sheath of the core welding wire is made of SPCC-SD cold-rolled low-carbon steel strip. The steel strip is cut to a suitable size and rolled into a "U" shape by a rolling mill forming roll. The prepared flux core raw materials are baked, mixed and added to the "U"-shaped groove of the steel strip in proportion. After drawing, layer winding and packaging, titanium-type flux core welding wire is obtained.

[0022] The superior effect of this invention lies in using inexpensive reduced ilmenite as the main raw material, and through the reasonable combination of other auxiliary materials, controlling the proportion of each material, especially the proportion between Mn, Si and FeO, and the proportion of the two components of the slag-forming agent, the final product has excellent welding performance, high strength, and low-temperature impact toughness close to that of welding wire made from rutile. Attached Figure Description

[0023] Figure 1 This invention yields a photograph of a titanium-type flux-cored welding wire based on reduced ilmenite. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. The following embodiments are provided to better understand this invention, but do not limit the invention. Unless otherwise specified, the experimental methods in the following embodiments are conventional methods.

[0025] Example

[0026] Titanium-type flux-cored welding wires were prepared according to the components and dosages specified in Table 1 below.

[0027] Reduced ilmenite, TiO2 content 60.2%, FeO content 5%.

[0028] The silicon-manganese alloy is FeMn68Si18, GB / T 4008-2008, in which the Mn content is 68% and the silicon content is 18%.

[0029] The iron-silicon alloy is FeSi75-A, GB / T 2272-2009, in which the Si content is 75%;

[0030] Electrolytic manganese, DJMnG, YB / T 051-2015;

[0031] Titanium-iron alloy, FeTi40-A, GB / T 3282-2012;

[0032] Ferroboron alloy, FeB12, GB / T 5682-2015;

[0033] Aluminum-magnesium alloy, FLM1, GB / T 5150-2004;

[0034] Table 1 Composition of titanium-type flux-cored welding wire

[0035]

[0036] The above embodiments and comparative examples were subjected to the following performance tests, and the results are shown in Table 2 below.

[0037] The flux-cored welding wire products were tested according to the technical requirements of GB / T 10045-2018 "Fluid-cored Welding Wires for Non-alloy Steel and Fine-grained Steel":

[0038] Tensile strength (Rm): 490~670MPa

[0039] Yield strength (Rel): ≥390MPa

[0040] Elongation at break (A): ≥18%

[0041] Impact absorption energy at -20℃ (KV2): ≥27J

[0042] Table 2. Performance Test of Deposited Metal from Flux-Cored Welding Wire

[0043] Welding wire sample Rm(MPa) Rel(MPa) A(％) KV2(J, -20℃) Example 1 572 503 24.5 108 Example 2 564 493 26 115 Example 3 552 481 26 143 Example 4 542 472 27 148 Example 5 553 484 26.5 152 Example 6 545 473 25.5 135 Comparative Example 1 548 475 27.5 112 Comparative Example 2 556 482 28 128 Comparative Example 3 493 425 26.5 55 Comparative Example 4 658 586 20.5 48

[0044] The data in Table 2 shows that by using appropriate raw material formulations, especially by adjusting the ratio of Mn, Si, and FeO while ensuring the Mn content, the welding performance of the welding wire can be significantly improved. In particular, the impact energy absorption at -20℃ is comparable to that of welding wires made from expensive rutile, but the manufacturing cost is significantly reduced.

[0045] In Comparative Example 3, the low Mn content resulted in low ∑Mn / ∑Si and low ∑Mn+∑Si / ∑FeO, leading to insufficient deoxidation capacity, low tensile strength, and a severe decrease in impact toughness.

[0046] In Comparative Example 4, the excessive Mn content resulted in excessively high ∑Mn / ∑Si and ∑Mn+∑Si / ∑FeO, leading to excessively high deoxidation capacity, excessively high tensile strength, and a severe decrease in impact toughness.

Claims

1. A titanium type flux cored wire based on reduced ilmenite consisting of a sheath and a core, characterized in that, The drug core comprises the following raw materials by mass fraction: 40-70 parts of reduced ilmenite, 15-30 parts of alloying agent, 5-10 parts of slag forming agent, 1-5 parts of deoxidizer, 1-5 parts of fluoride, and 1-30 parts of iron powder; and the use amount of each material satisfies the following relationships: ∑Mn / ∑Si=3.2-4.5, ∑Mn+∑Si / ∑FeO=5.5-6.8; ∑Mn, ∑Si and ∑FeO represent the total mass of Mn, Si and FeO in the materials respectively; and the mass content of Mn in the raw materials is 10-17 wt%.

2. The titanium-type flux-cored wire of claim 1, wherein The mass content of Mn in the raw materials is 13-15 wt%.

3. The titanium-type flux-cored wire of claim 1, wherein The reduced ilmenite has TiO2≥58 wt% and FeO≤5.5 wt%.

4. The titanium-type flux-cored wire of claim 1 wherein, The reduced ilmenite has TiO2≥60 wt% and FeO≤5.0 wt%.

5. The titanium-type flux-cored wire of claim 1 wherein, The drug core comprises the following raw materials by mass fraction: 46-65 parts of reduced ilmenite, 20-25 parts of alloying agent, 5-10 parts of slag forming agent, 3-5 parts of deoxidizer, 1-3 parts of fluoride, and 1-30 parts of iron powder.

6. The titanium-type flux-cored wire of claim 1 wherein, The alloying agent is at least two of silicon-manganese alloy, silicon-iron alloy, electrolytic manganese, titanium-iron, boron-iron and titanium-boron-iron.

7. The titanium-type flux-cored wire of claim 1 wherein, The slag forming agent is a combination of component A and component B, component A is at least one of zircon sand, quartz sand and feldspar; and component B is at least one of potassium titanate and sodium titanate.

8. The titanium-type flux-cored wire of claim 7, wherein The mass ratio of component A to component B in the slag forming agent is 0.5-2:

1.

9. The titanium-type flux-cored wire of claim 7, wherein The mass ratio of component A to component B in the slag forming agent is 0.9-1.6:

1.

10. The titanium-type flux-cored wire of claim 1 wherein, The deoxidizer is at least one of magnesium powder and aluminum-magnesium alloy powder; and the fluoride is at least one of sodium fluoride, sodium fluorosilicate and potassium fluorosilicate.

11. A method of making the titanium-type flux-cored wire according to any one of claims 1 to 10, characterized in that The method comprises the following steps: The core welding wire sheath is made of SPCC-SD cold-rolled low-carbon steel strip, the steel strip is cut to a suitable size, and is rolled into a "U" shape by a forming roller; the prepared raw materials of the drug core are baked and mixed, and then are added into the "U" shaped groove of the steel strip in a proper proportion; and after drawing, layer winding and packaging, a titanium type drug core welding wire is obtained.

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