Arc welding flux for 62 kg grade wind power tower cylinder welding special for pressure standard

Abstract

The application provides a 62kg-grade special submerged arc flux for wind power tower cylinder welding meeting a pressure standard, which is composed of raw materials with the following mass percentages: calcium fluoride 15-20%, aluminum oxide 15-20%, marble 15-20%, fused magnesite 10-15%, rutile 10-15%, mica 10-15%, manganese ore powder 5-10%, ferromanganese-silicon 5-10%, and nickel-magnesium alloy 1-5%; and the sum of the weight percentages of the components is 100%. The 62kg-grade special submerged arc flux for wind power tower cylinder welding meeting a pressure standard has the advantages of meeting large-current welding, easy deslagging, beautiful weld formation, small post-weld machining allowance, and the like, can be used for welding of the wind power tower cylinder meeting the pressure standard, can guarantee the welding quality, and is mainly used for welding of large thick plate steel structures.

Description

Technical Field

[0001] This invention belongs to the field of submerged arc welding, and in particular relates to a 62 kg-class submerged arc welding flux for welding wind turbine towers that meets pressure bearing standards. Background Technology

[0002] As my country's wind power construction enters a period of rapid development, the requirements for corresponding welding materials are becoming increasingly stringent. The welding characteristics of pressure-bearing standard wind turbine tower structures are large welding volume and high welding quality requirements. Conventional welding methods have long welding cycles, making them difficult to meet the needs of large-scale production. Submerged arc welding is not only highly efficient but also offers excellent welding technology; however, it places very high demands on the comprehensive performance indicators of the welding materials. The steel used in pressure-bearing standard wind turbine tower structures has already met higher requirements for tensile strength and low-temperature impact toughness, which in turn places corresponding requirements on the tensile strength and low-temperature impact toughness of the matching welding materials. Summary of the Invention

[0003] In view of this, the present invention aims to overcome the defects in the prior art and propose a 62 kg-class submerged arc welding flux for wind turbine tower welding that meets pressure bearing standards.

[0004] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0005] A 62 kg-class submerged arc welding flux specifically for welding wind turbine towers that meets pressure bearing standards, the flux is composed of raw materials comprising the following mass percentages:

[0006] Calcium fluoride 15-20%, alumina 15-20%, marble 15-20%, fused magnesia 10-15%, rutile 10-15%, mica 10-15%, manganese ore powder 5-10%, silicon-manganese alloy 5-10%, nickel-magnesium alloy 1-5%; the sum of the weight percentages of all components is 100%.

[0007] Preferably, the submerged arc welding flux is composed of raw materials comprising the following mass percentages:

[0008] Calcium fluoride 20%, alumina 20%, marble 15%, fused magnesia 10%, rutile 10%, mica 10%, manganese ore powder 5%, silicon manganese alloy 5%, nickel magnesium alloy 5%.

[0009] Preferably, the submerged arc welding flux is composed of raw materials comprising the following mass percentages:

[0010] Calcium fluoride 15%, alumina 15%, marble 20%, fused magnesia 10%, rutile 15%, mica 10%, manganese ore powder 5%, silicon manganese alloy 5%, nickel magnesium alloy 5%.

[0011] Preferably, the submerged arc welding flux is composed of raw materials comprising the following mass percentages:

[0012] Calcium fluoride 17%, alumina 17%, marble 16%, fused magnesia 12%, rutile 12%, mica 12%, manganese ore powder 6%, silicon manganese alloy 6%, nickel magnesium alloy 2%.

[0013] Calcium fluoride has a low melting point and is relatively reactive at high temperatures. It reacts with silicon dioxide and titanium dioxide to produce silicon tetrafluoride and titanium tetrafluoride gases. These gases can expel hydrogen from the arc zone, preventing hydrogen from dissolving in the metal and reducing the chance of porosity. Due to its low melting point, it has a diluting effect on the slag, lowering the slag melting point and effectively desulfurizing the metal. This reduces the oxygen content of the weld metal and improves the weld's plasticity and impact toughness. In this invention, the calcium fluoride content is 15-20%.

[0014] Alumina is a major component of welding flux, characterized by being derived from calcined α-alumina. By adjusting the content and ratio of alumina, the viscosity and melting point of the slag can be effectively controlled, the crystal water content of the finished flux can be reduced, and the content of harmful elements S / P can be decreased. In this invention, its content is 15-20%.

[0015] The addition of marble is a key technology of this invention. The carbon monoxide and carbon dioxide produced by the decomposition of marble can combine with oxygen / hydrogen in the weld, which helps to reduce the oxygen content in the weld and the partial pressure of hydrogen in the arc atmosphere. This reduces the content of harmful oxygen / hydrogen elements in the weld, improves low-temperature impact toughness, and reduces the generation of hydrogen-induced cracks. In this invention, the marble content is 15-20%.

[0016] Fused magnesia is an excellent slag-forming material, increasing the permeability of the molten slag, reducing its viscosity, and improving the desulfurization capacity of the weld pool during welding, while also reducing the content of impurity elements. In this invention, the fused magnesia content is 10-15%.

[0017] Rutile primarily adjusts the viscosity and surface tension of the molten slag, which is beneficial for slag removal and weld formation. TiO2 also has the characteristic of short slag, preventing the molten slag from becoming long and thus losing its protective effect on the molten pool. It plays a key role in excellent slag removal during welding. However, excessive addition should be avoided, as it will deteriorate the process performance during welding. In this invention, the rutile content is 10-15%.

[0018] Mica is a key component of the flux in this invention, which can improve arc stability, enhance the flux's process performance, and refine weld ripples. In this invention, its content is 10-15%.

[0019] The addition of manganese ore powder prevents excessive loss of Mn in the molten pool, ensuring a certain Mn content. Manganese oxide in the ore is reduced to Mn under the action of an electric arc, which reacts with iron oxide in the molten pool to reduce the O content in the weld, thus reducing the inclusion content and playing an important role in improving the mechanical properties of the weld. Manganese oxide can also react with sulfur in the molten pool to remove sulfur. As a low-melting-point substance, manganese oxide can lower the melting point of the flux, ensuring the slag has suitable viscosity and surface tension, improving slag removal, refining the molten pool, and acting as a tempering agent. In this invention, its content is 5-10%.

[0020] Silicon-manganese alloy is a good deoxidizer and desulfurizer, which can significantly improve the strength and toughness of welds. However, its content should not be too high, otherwise it is easy to cause center cracks in the weld. In this invention, its content is 5-10%.

[0021] In this invention, nickel-magnesium alloys can introduce nickel into the weld, which improves the weld's strength and toughness. However, the content cannot be too high, as excessive nickel content can lead to excessively high weld strength and decreased impact toughness. Magnesium can reduce the oxygen content in the weld, purify the weld metal, and improve impact toughness. In this invention, its content is 1-5%.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] The 62 kg-class submerged arc welding flux for welding pressure-bearing standard wind turbine towers described in this invention meets the requirements for high-current welding, and is easy to remove slag, produces beautiful weld beads, and has a small post-weld machining allowance. It can be used for welding pressure-bearing standard wind turbine towers and can guarantee welding quality. It is mainly used for welding large thick plate steel structures, such as large pressure-bearing standard wind turbine tower structures.

[0024] The 62 kg-grade submerged arc welding flux for wind turbine tower welding that meets pressure bearing standards described in this invention contains a variety of trace alloying elements. By refining the grains and improving the intergranular microstructure, it can significantly improve impact toughness and ensure the yield strength ratio of the weld. The addition of various beneficial materials can effectively reduce the content of harmful elements such as sulfur, phosphorus, and hydrogen, reduce damage to impact toughness, and improve the overall performance of the weld. The high alloying element content of this invention can effectively compensate for the loss of alloying elements during the welding process, ensuring that the mechanical properties of the weld meet the standard requirements.

[0025] The 62 kg-grade submerged arc welding flux for wind turbine tower welding that meets pressure-bearing standards described in this invention contains many raw materials with stable physical properties. For example, alumina has a very stable melting and solidification point, which can adjust the melting and solidification points of the molten pool, thereby improving slag removal. Marble can decompose during welding, and through chemical reactions, it can effectively reduce the content of harmful elements such as sulfur and phosphorus in the weld. Mica can adjust the arc stability and improve weld formation. Multiple alloys are added to improve the low-temperature toughness of the weld metal. Detailed Implementation

[0026] Unless otherwise defined, the technical terms used in the following embodiments have the same meanings as commonly understood by those skilled in the art. Unless otherwise specified, the experimental reagents used in the following embodiments are conventional biochemical reagents; and the experimental methods described are conventional methods.

[0027] The present invention will be described in detail below with reference to the embodiments.

[0028] Example 1

[0029] The preparation method of a 62 kg-class submerged arc welding flux for wind turbine tower welding that meets pressure bearing standards is as follows:

[0030] (1) The submerged arc welding flux is composed of the following raw materials in the following mass percentages: calcium fluoride 20%, alumina 20%, marble 15%, fused magnesia 10%, rutile 10%, mica 10%, manganese ore powder 5%, silicon manganese alloy 5%, nickel magnesium alloy 5%.

[0031] (2) The binder is potassium sodium water glass with a modulus of 3.1-3.2 and a potassium-sodium ratio of 2:1.

[0032] (3) The above-mentioned components were used to prepare the submerged arc welding flux for testing. According to the national standard GB / T 36034-2018, the chemical composition analysis and mechanical property test of the deposited metal were carried out in conjunction with the submerged arc welding wire SU41 with a specification of Φ4.0. The results are shown in Table 1-3.

[0033] Welding specifications: The welding power source is DC reverse polarity, current 550A, voltage 32V, welding speed 30m / h, and interpass temperature 135-165℃.

[0034] Table 1 Flux S / P Content

[0035] Guaranteed value ≤0.020 ≤0.020 Example value 0.004 0.010

[0036] Table 2 Chemical composition of deposited metal

[0037] Guaranteed value ≤0.010 ≤0.010 Example value 0.002 0.009

[0038] Table 3 Measured values ​​of mechanical properties of welded metal

[0039] Standard value 620-820 ≥500 ≥15.0 ≥47 Measured value 655 560 19.0 112 118 119

[0040] Example 2

[0041] The preparation method of a 62 kg-class submerged arc welding flux for wind turbine tower welding that meets pressure bearing standards is as follows:

[0042] (1) This submerged arc welding flux is composed of raw materials comprising the following mass percentages:

[0043] Calcium fluoride 15%, alumina 15%, marble 20%, fused magnesia 10%, rutile 15%, mica 10%, manganese ore powder 5%, silicon manganese alloy 5%, nickel magnesium alloy 5%;

[0044] (2) The binder is potassium sodium water glass with a modulus of 3.1-3.2 and a potassium-sodium ratio of 2:1.

[0045] (3) The above-mentioned components were used to prepare the submerged arc welding flux for testing. According to the national standard GB / T 36034-2018, the chemical composition analysis and mechanical property test of the deposited metal were carried out in conjunction with the submerged arc welding wire SU41 with a specification of Φ4.0. The results are shown in Table 4-6.

[0046] Welding specifications: The welding power source is DC reverse polarity, current 550A, voltage 32V, welding speed 30m / h, and interpass temperature 135-165℃.

[0047] Table 4 Flux S / P Content

[0048] Guaranteed value ≤0.020 ≤0.020 Example value 0.006 0.010

[0049] Table 5 Chemical composition of deposited metal

[0050] Guaranteed value ≤0.010 ≤0.010 Example value 0.005 0.009

[0051] Table 6 Measured values ​​of mechanical properties of welded metal

[0052] Standard value 620-820 ≥500 ≥15.0 ≥47 Measured value 672 583 18.0 103 105 101

[0053] Example 3

[0054] The preparation method of a 62 kg-class submerged arc welding flux for wind turbine tower welding that meets pressure bearing standards is as follows:

[0055] (1) This submerged arc welding flux is composed of raw materials comprising the following mass percentages:

[0056] Calcium fluoride 17%, alumina 17%, marble 16%, fused magnesia 12%, rutile 12%, mica 12%, manganese ore powder 6%, silicon manganese alloy 6%, nickel magnesium alloy 2%.

[0057] (2) The binder is potassium sodium water glass with a modulus of 3.1-3.2 and a potassium-sodium ratio of 2:1.

[0058] (3) The above-mentioned components were used to prepare the submerged arc welding flux for testing. According to the national standard GB / T36034-2018, the chemical composition analysis and mechanical property test of the deposited metal were carried out in conjunction with the submerged arc welding wire SU41 with a specification of Φ4.0. The results are shown in Table 7-9.

[0059] Welding specifications: The welding power source is DC reverse polarity, current 550A, voltage 32V, welding speed 30m / h, and interpass temperature 135-165℃.

[0060] Table 7 Flux S / P Content

[0061]

[0062]

[0063] Table 8 Chemical composition of deposited metal

[0064] Guaranteed value ≤0.010 ≤0.010 Example value 0.003 0.007

[0065] Table 9 Measured values ​​of mechanical properties of welded metal

[0066] Standard value 620-820 ≥500 ≥15.0 ≥47 Measured value 668 562 20.0 129 135 128

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A 62 kg-class submerged arc welding flux specifically for welding wind turbine towers that meets pressure bearing standards, characterized in that: This submerged arc welding flux is composed of raw materials comprising the following percentages by mass: Calcium fluoride 17%, alumina 17%, marble 16%, fused magnesia 12%, rutile 12%, mica 12%, manganese ore powder 6%, silicon manganese alloy 6%, nickel magnesium alloy 2%.

Images