Submerged-arc welding flux for welding chromium-molybdenum-vanadium steel and preparation method of submerged-arc welding flux

Abstract

The invention relates to the technical field of submerged-arc welding agents, in particular to a submerged-arc welding agent for welding chrome-molybdenum-vanadium steel and a preparation method of the submerged-arc welding agent. The conventional welding flux for the chrome-molybdenum-vanadium steel is not obvious in the effect of improving the toughness of a welded joint, and the tensile strength of the welded joint is difficult to reach more than 650 MPa. In order to solve the technical problems, the submerged arc welding flux for chrome-molybdenum-vanadium steel welding is provided, raw materials of the submerged arc welding flux comprise mixed powder and potassium-sodium water glass, compared with a traditional welding flux, the composition and proportion of the obtained welding flux are innovated, particularly ilmenite, molybdenum-aluminum ore, chromite and the like are added, and the welding flux has the beneficial effects that the welding flux is environmentally friendly; and more stable welding quality can be provided for submerged-arc welding, chemical components of the submerged-arc welding flux are highly matched with chemical components of high-strength steel such as chrome-molybdenum-vanadium steel, and the submerged-arc welding flux has good application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of submerged arc welding fluxes, and in particular to a submerged arc welding flux for chromium-molybdenum-vanadium steel welding and a preparation method thereof. Background Art

[0002] With the rapid rise of national industrial production, especially in the fields of petrochemical, electric power, shipbuilding and other heavy industries, the demand for pressure vessels has increased dramatically. In the production process, welding technology plays a vital role.

[0003] The quality of manual welding is unstable and may lead to a high defect rate due to improper operation. At the same time, manual welding generates a lot of spatter, which requires a lot of cleaning work. In addition, the environmental pollution and safety hazards during welding are also high.

[0004] Submerged arc welding is highly efficient and can be used for long periods of time. Second, submerged arc welding can provide a large welding heat input, resulting in high-quality welds and strong weld joints, which is particularly suitable for welding thick plates. Since continuous welding wire and protective agent are used during welding, the molten pool is stable and the arc stability is good. In contrast, the disadvantages of manual welding are more obvious. The role of flux is extremely important for submerged arc welding to achieve such a good welding effect. The flux can provide a stable arc environment for welding, and the flux can also improve the fluidity of the molten pool.

[0005] Currently, chromium-molybdenum-vanadium steel is often used in the production of pressure vessels. Conventional chromium-molybdenum-vanadium steel fluxes are not very effective in improving the toughness of welded joints, and the tensile strength of welded joints is difficult to reach above 650MPa. Summary of the invention

[0006] The problem in the prior art is that conventional fluxes for chromium-molybdenum-vanadium steels have little effect on improving the toughness of welded joints, and the tensile strength of welded joints is difficult to reach above 650 MPa. In view of the above technical problems, the present invention provides a submerged arc flux for welding chromium-molybdenum-vanadium steels, wherein the raw materials include a mixed powder and potassium-sodium water glass, wherein the mixed powder, in terms of weight percentage, includes the following components:

[0007]

[0008] Preferably, a submerged arc welding flux for chromium-molybdenum-vanadium steel welding, the raw materials of which include mixed powder and potassium-sodium water glass, the mixed powder, in terms of weight percentage, includes the following components:

[0009]

[0010] Preferably, a submerged arc welding flux for chromium-molybdenum-vanadium steel welding, the raw materials of which include mixed powder and potassium-sodium water glass, the mixed powder, in terms of weight percentage, includes the following components:

[0011]

[0012] A submerged arc welding flux for chromium-molybdenum-vanadium steel welding, the preparation method of which comprises the following steps:

[0013] (1) fully mixing the formulated amounts of fluorite, calcium oxide, aluminum oxide, magnesia, titanium dioxide, ilmenite, molybdenum aluminum ore and chromite to obtain a mixed powder, adding potassium sodium water glass to the mixed powder, stirring evenly, and granulating with a granulator to obtain a granular mixed material;

[0014] (2) The granular mixed material is sintered at high temperature and then sieved to obtain a submerged arc welding flux with a desired particle size.

[0015] Preferably, the addition amount of the potassium sodium water glass is 22-30% of the total weight of the mixed powder.

[0016] Preferably, the modulus of the potassium-sodium water glass is 3.1 and the density is 1.3 g / cm 3 .

[0017] A submerged arc welding method for chromium-molybdenum-vanadium steel adopts the above-mentioned submerged arc welding flux as welding.

[0018] Preferably, the submerged arc welding current is 500-600A, the welding voltage is 30-36V, and the welding speed is 20-26cm / min.

[0019] The present invention has the following beneficial effects:

[0020] (1) In the flux composition of the present invention, the chromium element provided by chromite can effectively prevent the oxidation of the weld, and in particular, can form dense chromium oxide (Cr2O3) in a high temperature environment, significantly improving the oxidation resistance and corrosion resistance of the weld;

[0021] (2) In the flux composition of the present invention, the molybdenum element of molybdenum aluminum ore is crucial for improving the strength, hardness and creep resistance of the weld at high temperature. Molybdenum can effectively improve the high-temperature mechanical properties of the weld, especially for chromium-molybdenum-vanadium steel exposed to high temperature conditions for a long time, and can significantly improve the durability of the weld;

[0022] (3) In the flux composition of the present invention, titanium in ilmenite can effectively reduce pores and cracks during welding through its deoxidation effect. Titanium not only improves the purity of the weld metal, but also improves the toughness of the weld and reduces the generation of hot cracks and cold cracks, especially for high-strength materials such as chromium-molybdenum-vanadium steel;

[0023] (4) The present invention is mainly used for welding chromium-molybdenum-vanadium steel with relatively large thickness. The preparation method of the present invention is simple, and it is also convenient to install and operate during welding work. It can ensure the effective combination of welding wire, base material and flux, reduce smoke and arc light, and effectively improve the welding working environment of workers;

[0024] (5) During the welding process, some components in the flux, such as fluorite and calcium oxide, can effectively reduce the generation and emission of harmful gases and reduce environmental pollution;

[0025] (6) Compared with traditional fluxes, the flux obtained by the present invention has made innovations in the selection and proportion of ingredients, especially the unique ratio of ilmenite, molybdenum aluminum ore and chromite, which can provide more stable welding quality, improve the performance of welded metal, and is highly compatible with the chemical composition of high-strength steels such as chromium-molybdenum-vanadium steel, meeting the needs of specific industries. DETAILED DESCRIPTION

[0026] The present invention is described in detail below with reference to the examples. However, it should be understood that the following examples are only illustrative of the embodiments of the present invention, and are not intended to limit the scope of the present invention.

[0027] The potassium-sodium water glass used in the following examples of the present invention has a modulus of 3.1 and a density of 1.3 g / cm 3 ,

[0028] The granulator used in the following embodiments of the present invention is produced by Shenzhen Baofeng Precious Metal Equipment Technology Co., Ltd., and its model is BF-XL100.

[0029] The fluorite used in the following embodiments of the present invention has a purity of 95%; the purity of calcium oxide is 98%; the purity of aluminum oxide is 93%; the purity of magnesia is 95%; and the purity of titanium dioxide is 95%.

[0030] The ilmenite used in the following examples of the present invention has a composition in which the mass percentage of FeTiO3 is 80%, the total mass percentage of silicon dioxide (SiO2) and aluminum oxide (Al2O3) is 3.8%, and the balance is FeO.

[0031] The molybdenum-aluminum ore used in the following embodiments of the present invention has the following components: the mass percentage of MoO3 is 75%, the mass percentage of Al2O3 is 20%, the mass percentage of crystal water is 0.53%, and the remainder is impurities.

[0032] The chromite used in the following examples of the present invention has a composition in which the mass percentage of Cr2O3 is 55%, the mass percentage of FeO is 25%, the mass percentage of Fe2O3 is 15%, and the remainder is impurities.

[0033] Example 1

[0034] A submerged arc welding flux for chromium-molybdenum-vanadium steel welding, the raw materials of which are mixed powder and potassium-sodium water glass, the mixed powder, in terms of weight percentage, is composed as follows:

[0035]

[0036] The addition amount of potassium sodium water glass is 22% of the total weight of the mixed powder.

[0037] The submerged arc welding flux for chromium-molybdenum-vanadium steel welding is prepared as follows:

[0038] (1) fully mixing the formulated amounts of fluorite, calcium oxide, aluminum oxide, magnesia, titanium dioxide, ilmenite, molybdenum aluminum ore and chromite to obtain a mixed powder, adding the formulated amount of potassium sodium water glass to the mixed powder, stirring evenly, and granulating with a granulator to obtain a granular mixed material;

[0039] (2) The granular mixture is sintered at 950° C. for 1.5 h, and then sieved to obtain a submerged arc welding flux with an average particle size of 50 mesh.

[0040] Example 2

[0041] A submerged arc welding flux for chromium-molybdenum-vanadium steel welding, the raw materials of which are mixed powder and potassium-sodium water glass, the mixed powder, in terms of weight percentage, is composed as follows:

[0042]

[0043] The addition amount of potassium sodium water glass is 30% of the total weight of the mixed powder.

[0044] The submerged arc welding flux for chromium-molybdenum-vanadium steel welding is prepared as follows:

[0045] (1) fully mixing the formulated amounts of fluorite, calcium oxide, aluminum oxide, magnesia, titanium dioxide, ilmenite, molybdenum aluminum ore and chromite to obtain a mixed powder, adding the formulated amount of potassium sodium water glass to the mixed powder, stirring evenly, and granulating with a granulator to obtain a granular mixed material;

[0046] (2) The granular mixture is sintered at 950° C. for 1.5 h, and then sieved to obtain a submerged arc welding flux with an average particle size of 50 mesh.

[0047] Example 3

[0048] A submerged arc welding flux for chromium-molybdenum-vanadium steel welding, the raw materials of which are mixed powder and potassium-sodium water glass, the mixed powder, in terms of weight percentage, is composed as follows:

[0049]

[0050] The addition amount of potassium sodium water glass is 25% of the total weight of the mixed powder.

[0051] The submerged arc welding flux for chromium-molybdenum-vanadium steel welding is prepared as follows:

[0052] (1) fully mixing the formulated amounts of fluorite, calcium oxide, aluminum oxide, magnesia, titanium dioxide, ilmenite, molybdenum aluminum ore and chromite to obtain a mixed powder, adding the formulated amount of potassium sodium water glass to the mixed powder, stirring evenly, and granulating with a granulator to obtain a granular mixed material;

[0053] (2) The granular mixture is sintered at 950° C. for 1.5 h, and then sieved to obtain a submerged arc welding flux with an average particle size of 50 mesh.

[0054] Comparative Example 1

[0055] A submerged arc welding flux for chromium-molybdenum-vanadium steel welding, the raw materials of which are mixed powder and potassium-sodium water glass, the mixed powder, in terms of weight percentage, is composed as follows:

[0056]

[0057]

[0058] The addition amount of potassium sodium water glass is 22% of the total weight of the mixed powder.

[0059] The submerged arc welding flux for chromium-molybdenum-vanadium steel welding is prepared as follows:

[0060] (1) fully mixing the formulated amounts of fluorite, calcium oxide, aluminum oxide, magnesia, titanium dioxide, ilmenite, molybdenum aluminum ore and chromite to obtain a mixed powder, adding the formulated amount of potassium sodium water glass to the mixed powder, stirring evenly, and granulating with a granulator to obtain a granular mixed material;

[0061] (2) The granular mixture is sintered at 950° C. for 1.5 h, and then sieved to obtain a submerged arc welding flux with an average particle size of 50 mesh.

[0062] Comparative Example 2

[0063] A submerged arc welding flux for chromium-molybdenum-vanadium steel welding, the raw materials of which are mixed powder and potassium-sodium water glass, the mixed powder, in terms of weight percentage, is composed as follows:

[0064]

[0065] The addition amount of potassium sodium water glass is 22% of the total weight of the mixed powder.

[0066] The submerged arc welding flux for chromium-molybdenum-vanadium steel welding is prepared as follows:

[0067] (1) fully mixing the formulated amounts of fluorite, calcium oxide, aluminum oxide, magnesia, titanium dioxide, ilmenite, molybdenum aluminum ore and chromite to obtain a mixed powder, adding the formulated amount of potassium sodium water glass to the mixed powder, stirring evenly, and granulating with a granulator to obtain a granular mixed material;

[0068] (2) The granular mixture is sintered at 950° C. for 1.5 h, and then sieved to obtain a submerged arc welding flux with an average particle size of 50 mesh.

[0069] Comparative Example 3

[0070] A submerged arc welding flux for chromium-molybdenum-vanadium steel welding, the raw materials of which are mixed powder and potassium-sodium water glass, the mixed powder, in terms of weight percentage, is composed as follows:

[0071]

[0072] The addition amount of potassium sodium water glass is 22% of the total weight of the mixed powder.

[0073] The submerged arc welding flux for chromium-molybdenum-vanadium steel welding is prepared as follows:

[0074] (1) fully mixing the formulated amounts of fluorite, calcium oxide, aluminum oxide, magnesia, titanium dioxide, ilmenite, molybdenum aluminum ore and chromite to obtain a mixed powder, adding the formulated amount of potassium sodium water glass to the mixed powder, stirring evenly, and granulating with a granulator to obtain a granular mixed material;

[0075] (2) The granular mixture is sintered at 950° C. for 1.5 h, and then sieved to obtain a submerged arc welding flux with an average particle size of 50 mesh.

[0076] Comparative Example 4

[0077] A submerged arc welding flux for chromium-molybdenum-vanadium steel welding, the raw materials of which are mixed powder and potassium-sodium water glass, the mixed powder, in terms of weight percentage, is composed as follows:

[0078]

[0079] The addition amount of potassium sodium water glass is 22% of the total weight of the mixed powder.

[0080] The submerged arc welding flux for chromium-molybdenum-vanadium steel welding is prepared as follows:

[0081] (1) fully mixing the formulated amounts of fluorite, calcium oxide, aluminum oxide, magnesia, titanium dioxide, ilmenite, molybdenum aluminum ore and chromite to obtain a mixed powder, adding the formulated amount of potassium sodium water glass to the mixed powder, stirring evenly, and granulating with a granulator to obtain a granular mixed material;

[0082] (2) The granular mixture is sintered at 950° C. for 1.5 h, and then sieved to obtain a submerged arc welding flux with an average particle size of 50 mesh.

[0083] Performance Testing

[0084] The submerged arc welding flux obtained in the embodiment of the present invention and the comparative example was subjected to submerged arc welding performance test, the metal workpiece was a 12CrMoV metal plate, the welding wire diameter was 4 mm, and the model was H08CrMoVA. The power supply was an AC positive power supply, the welding current was 560A, the welding voltage was 32V, the welding speed was 24cm / min, and the I-type groove was welded on both sides. The mechanical property test results are shown in Table 1.

[0085] Table 1

[0086]

[0087] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A submerged arc welding flux for chromium-molybdenum-vanadium steel welding, characterized in that: The raw materials include mixed powder and potassium sodium water glass, and the mixed powder, in terms of weight percentage, includes the following components: Fluorite 15-20%; Calcium oxide 25-35%; Alumina 10-25%; Magnesia 10-20%; Titanium dioxide 5-10%; Ilmenite 8-15%; Molybdenum aluminum ore 2-4%; Chromite 1-3%.

2. A submerged arc welding flux for chromium-molybdenum-vanadium steel welding according to claim 1, characterized in that: The mixed powder comprises the following components by weight percentage: Fluorite 15%; Calcium oxide 28%; Alumina 22%; Magnesia 14%; Titanium dioxide 7%; Ilmenite 12%; Molybdenum aluminum ore 2%; Chromite 2%.

3. A submerged arc welding flux for chromium-molybdenum-vanadium steel welding according to claim 1, characterized in that: The mixed powder comprises the following components by weight percentage: Fluorite 17%; Calcium oxide 25%; Alumina 20%; Magnesia 15%; Titanium dioxide 8%; Ilmenite 10%; Molybdenum aluminum ore 3%; Chromite 2%.

4. A submerged arc welding flux for chromium-molybdenum-vanadium steel welding according to any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: (1) fully mixing the formulated amounts of fluorite, calcium oxide, aluminum oxide, magnesia, titanium dioxide, ilmenite, molybdenum aluminum ore and chromite to obtain a mixed powder, adding potassium sodium water glass to the mixed powder, stirring evenly, and granulating with a granulator to obtain a granular mixed material; (2) The granular mixed material is sintered at high temperature and then sieved to obtain a submerged arc welding flux with a desired particle size.

5. A submerged arc welding flux for chromium-molybdenum-vanadium steel welding according to claim 4, characterized in that: The addition amount of the potassium sodium water glass is 22-30% of the total weight of the mixed powder.

6. A submerged arc welding flux for chromium-molybdenum-vanadium steel welding according to claim 4, characterized in that: The modulus of the potassium sodium water glass is 3.1 and the density is 1.3 g / cm 3 .

7. A submerged arc welding method for chromium-molybdenum-vanadium steel, characterized in that: The submerged arc welding flux for welding chromium-molybdenum-vanadium steel according to any one of claims 1 to 6 is used.

8. The submerged arc welding method for chromium-molybdenum-vanadium steel according to claim 7, characterized in that: The submerged arc welding current is 500-600A, the welding voltage is 30-36V, and the welding speed is 20-26cm / min.

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