A high-toughness and high-strength steel basic welding rod and its preparation method

Abstract

The application provides a high-toughness high-strength steel alkaline electrode and a preparation method thereof. The electrode comprises a core and a coating, and the coating is formed by mixing solid components and liquid components. The solid components comprise the following raw materials in parts by weight: 42-50 parts of marble, 25-33 parts of fluorite, 7-10 parts of carbonate, 5-7 parts of manganese iron, 4-5 parts of sodium fluoride, 2-3 parts of phlogopite and 2-3 parts of high-entropy rare earth oxide. The liquid components are binders, which comprise the following raw materials in parts by weight: 78-82 parts of modified potassium-sodium water glass, 17-20 parts of hydroxyethyl cellulose and 1-2 parts of lithium hydroxide. The liquid components account for 21-24% of the mass of the solid components. The high-toughness high-strength steel alkaline electrode can increase the high-temperature stability of the coating, inhibit the desorption of diffusible hydrogen at the welding temperature, reduce the content of diffusible hydrogen in the weld, refine the alloy structure, increase the content of metal acicular ferrite in the weld and improve the toughness of the weld.

Description

Technical Field

[0001] The invention belongs to the technical field of metal welding, and particularly relates to a high-toughness and high-strength steel basic welding rod and a preparation method thereof. Background Art

[0002] With the rapid development of modern industry, high-strength steel is increasingly used in society, raising the question of welding high-strength steel. Despite its high strength, high-strength steel has limited toughness reserves and is particularly sensitive to hydrogen-induced cracking. During welding, hydrogen diffusion is difficult to suppress under high temperatures and high voltages, posing a significant challenge to the durability of the welded steel. Therefore, optimizing welding rod composition has become a research priority.

[0003] Rare earth oxides in welding rod coatings have the functions of grain refinement, deoxidation and desulfurization, and reducing the hydrogen diffusion coefficient. They can effectively reduce the diffusible hydrogen content in the weld, purify the weld, and improve the impact toughness of the weld metal. However, when the rare earth oxide content is too high, the rare earth oxide will decompose at the high welding temperatures, causing the trapped hydrogen to re-desorb, which in turn increases the diffusible hydrogen content and reduces weld toughness. Therefore, the amount of rare earth oxide added needs to be strictly controlled. In addition, water glass is a commonly used binder in welding rod coatings. Although water glass has strong adhesion and is relatively low in cost, it has poor water resistance and easily absorbs water in humid environments. It also quickly loses water and becomes brittle at high temperatures, causing the coating to crack.

[0004] Based on the above background technology, there is an urgent need to develop a high-toughness welding rod suitable for high-strength steel welding, whose coating needs to have excellent high-temperature stability and water resistance to cope with the problem of hydrogen-induced cracking in high-strength steel welding and improve the overall performance of the weld joint. Summary of the Invention

[0005] The first object of the present invention is to provide a high-toughness and high-strength steel basic welding rod, which has excellent high-temperature stability, can effectively control the hydrogen content of the weld, and improve the toughness of the weld.

[0006] The second object of the present invention is to provide a method for preparing a high-toughness and high-strength steel basic welding rod.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A high-toughness, high-strength steel basic welding rod comprises a welding core and a coating, wherein the coating is formed by mixing a solid component and a liquid component; the solid component comprises the following raw materials in parts by weight: 42-50 parts of marble, 25-33 parts of fluorite, 7-10 parts of carbonate, 5-7 parts of ferromanganese, 4-5 parts of sodium fluoride, 2-3 parts of phlogopite, and 2-3 parts of high-entropy rare earth oxide; the liquid component is a binder and comprises the following raw materials in parts by weight: 78-82 parts of modified potassium-sodium water glass, 17-20 parts of hydroxyethyl cellulose, and 1-2 parts of lithium hydroxide; the liquid component accounts for 21-24% of the mass of the solid component.

[0009] Furthermore, the method for preparing the high entropy rare earth oxide particles comprises the following steps:

[0010] (1) weighing each rare earth nitrate raw material in an equal molar ratio, adding ethanol and water to dissolve, and obtaining a mixed solution;

[0011] (2) adding liquid ammonia to the mixed solution and stirring to react, and filtering to obtain a precipitate;

[0012] (3) mixing the precipitate with n-pentanol and performing rotary evaporation to obtain a precursor powder;

[0013] (4) Sintering the precursor powder at 1000-1100° C. for 2-3 h in an air atmosphere and grinding the powder to obtain a high entropy rare earth oxide.

[0014] Furthermore, the diameter of the high-entropy rare earth oxide is 20 to 100 nm.

[0015] The high-entropy rare earth oxide of the present invention is composed of 5 or more rare earth nitrates in an equimolar ratio, and forms a single lattice structure in the form of a solid solution through sintering or other methods. It has a highly uniform chemical composition and lattice distortion effect. The mixing of multiple elements significantly increases the entropy value of the system, thereby promoting structural stability and thermodynamic stability.

[0016] Furthermore, the rare earth nitrate raw materials in step (1) are composed of at least five of La(NO3)3, Ce(NO3)3, Nd(NO3)3, Sm(NO3)3, Gd(NO3)3, Y(NO3)3, and Er(NO3)3; the ratio of the total mass of the rare earth nitrate raw materials to anhydrous ethanol and deionized water is 1g:(5-10)mL:(50-80)mL; and the temperature of the rotary evaporation is 40-60°C.

[0017] Furthermore, the molar ratio of nitrate to liquid ammonia in the mixed solution in step (2) is 1:(1.5-2); the stirring reaction time is 1-2 hours; and the amount ratio of the precipitate to n-pentanol in step (3) is 1 g:(10-20) mL.

[0018] Furthermore, the preparation method of the modified potassium-sodium water glass comprises the following steps:

[0019] (a) adding magnesium oxide to a silane coupling agent solution, stirring for reaction, and drying to obtain modified magnesium oxide;

[0020] (b) adding potassium silicate, sodium silicate and modified magnesium oxide into water, heating and stirring to react, thereby obtaining modified potassium sodium water glass.

[0021] Furthermore, the silane coupling agent in step (a) is 3-hydroxypropyltrimethoxysilane or 3-hydroxypropyltriethoxysilane; the mass ratio of the magnesium oxide to the silane coupling agent is (10-12):1; the solvent of the silane coupling agent solution is toluene; the stirring time is 10-12 hours; the drying temperature is 80-90°C and the drying time is 4-5 hours.

[0022] Furthermore, in step (b), the mass ratio of potassium silicate, sodium silicate, and modified magnesium oxide is 100:(20-25):(0.5-1); the temperature of the heating and stirring is 50-70°C, and the time is 1-2h; the modulus of the potassium silicate is 2.7-2.9, and the modulus of the sodium silicate is 2.3-2.5.

[0023] The method for preparing the high-toughness and high-strength steel basic welding rod comprises the following steps:

[0024] The high-strength steel is drawn, cut, polished and cleaned to obtain a welding core; the liquid components of the coating are mixed uniformly according to the weight parts to obtain a binder; the solid components in the coating are mixed according to the weight parts, and then the binder is added and stirred uniformly to obtain a viscous coating; the viscous coating is applied to the welding core to form a coating, and the coating is dried and then baked to obtain a high-toughness and high-strength steel basic welding rod.

[0025] Furthermore, the drying process is as follows: first, keep the temperature at 140-160° C. for 0.5-1.5 hours, then heat to 240-260° C. and keep the temperature for 0.5-1.5 hours.

[0026] The beneficial technical effects of the present invention are:

[0027] 1. This invention incorporates high-entropy rare earth oxides into the electrode coating. By subjecting the rare earth oxides to high-entropy treatment, their high-temperature stability is enhanced, thereby suppressing the desorption of diffusible hydrogen at welding temperatures. This improvement increases the amount of rare earth oxide added, further reducing the content of diffusible hydrogen in the weld. Furthermore, the high-entropy rare earth oxide particles refine the weld alloy structure and increase the content of metallic acicular ferrite, significantly improving weld toughness.

[0028] 2. The present application also uses a binder in the welding rod coating, which is prepared by adding high-temperature-resistant modified magnesium oxide to water glass, and then compounding it with hydroxyethyl cellulose and lithium hydroxide, which can improve the high-temperature performance of the coating, inhibit the cracking of the coating at high temperature, wherein the hydroxyethyl cellulose also has good plasticity and flexibility, and can be emulsified into a film to block external moisture, and when compounded with water glass as a binder, it can slow down the moisture absorption speed of the water glass, reduce the brittleness of the coating, increase the high-temperature stability of the coating, and improve the comprehensive performance of the coating. DETAILED DESCRIPTION

[0029] The following is a further detailed description of the present application in conjunction with specific preferred embodiments, which cannot be deemed to limit the specific implementation of the present application to these descriptions. For those of ordinary skill in the art to which the present application belongs, without departing from the concept of the present application, a number of simple deductions or substitutions can also be made, which should be regarded as falling within the scope of protection of the present application. The specific conditions not mentioned in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, if not specially mentioned, are conventional products obtained through market channels.

[0030] (I) Examples

[0031] Example 1

[0032] Example 1 provides a high-toughness high-strength steel basic welding rod, which comprises a welding core and a coating covering the welding core; the coating is formed by mixing solid components and liquid components. The solid components are composed of the following components in weight parts: 45 parts of marble, 30 parts of fluorite, 8 parts of carbonate, 6 parts of manganese iron, 5 parts of sodium fluoride, 3 parts of phlogopite, and 3 parts of high-entropy rare earth oxide; the liquid component is a binder, which is composed of the following raw materials in weight parts: 80 parts of modified potassium-sodium water glass, 18 parts of hydroxyethyl cellulose, and 2 parts of lithium hydroxide. The liquid component accounts for 22% of the mass of the solid component. The welding core of the present application can be the same as the composition of the high-strength steel base material.

[0033] The above-mentioned high-entropy rare earth oxide is specifically prepared as follows:

[0034] (1) According to the molar ratio of La(NO3)3, Ce(NO3)3, Nd(NO3)3, Sm(NO3)3, and Gd(NO3)3, weigh each nitrate salt, then according to the ratio of the total mass of each rare earth nitrate to anhydrous ethanol and deionized water is 1g:5mL:50mL, add each rare earth nitrate raw material to the mixed solvent of anhydrous ethanol and deionized water to obtain a mixed solution;

[0035] (2) Add liquid ammonia to the mixed solution, the molar ratio of nitrate in the mixed solution to liquid ammonia is 1:1.8, stir at 400r / min for 1h, and then filter to obtain a precipitate;

[0036] (3) The precipitate was mixed with n-pentanol at 1 g:20 mL, and rotary evaporation treatment was performed at 60℃ to obtain a precursor powder;

[0037] (4) The precursor was placed in an alumina crucible, sintered at 1100℃ for 3h by a muffle furnace, the heating rate was 5℃ / min, and high-entropy rare earth oxide with a particle diameter of 50nm was obtained after grinding.

[0038] The specific preparation process of the modified potassium-sodium water glass is as follows:

[0039] (a) Magnesium oxide was added to a toluene solution of 3-hydroxypropyltrimethoxysilane, stirred at 400r / min for 10h, and then dried at 80℃ for 4h after filtration to obtain modified magnesium oxide; wherein the mass ratio of magnesium oxide to silane coupling agent was 10:1;

[0040] (b) Potassium silicate, sodium silicate and modified magnesium oxide were added to deionized water, stirred at 70℃ and 400r / min for 1h to obtain modified potassium-sodium water glass; wherein the mass ratio of potassium silicate, sodium silicate and modified magnesium oxide was 100:25:1, the modulus of potassium silicate was 2.8, and the modulus of sodium silicate was 2.4.

[0041] Example 1 also provides a preparation method of the above-mentioned high-toughness high-strength steel basic welding rod. Taking a H785D type steel plate as an example, the specific preparation process is as follows:

[0042] The H785D type steel plate was drawn and cut, polished and cleaned with acetone to remove surface oil and rust to obtain a welding core; the liquid components of the coating were mixed uniformly according to the above-mentioned ratio to obtain a binder; the solid components of the coating were mixed according to the above-mentioned ratio, and then the binder was added and stirred uniformly to obtain a viscous coating; the viscous coating was extruded and coated on the welding core to form a coating, and then dried at room temperature, followed by drying treatment, wherein the drying treatment process was 150℃ for 1h, and then the furnace was cooled to room temperature, to obtain a high-toughness high-strength steel basic welding rod.

[0043] Example 2

[0044] Example 2 provides a high-toughness high-strength steel basic welding rod, which comprises a welding core and a coating covering the welding core; the coating is formed by mixing solid components and liquid components. The solid components are composed of the following components in parts by weight: 42 parts of marble, 33 parts of fluorite, 7 parts of carbonate, 7 parts of manganese iron, 5 parts of sodium fluoride, 3 parts of phlogopite, and 3 parts of high-entropy rare earth oxide; the liquid component is a binder, which is composed of the following raw materials in parts by weight: 82 parts of modified potassium-sodium water glass, 17 parts of hydroxyethyl cellulose, and 1 part of lithium hydroxide. The liquid component accounts for 21% of the mass of the solid component. The welding core of the present application can be the same as the composition of the high-strength steel base material.

[0045] The specific preparation process of the high-entropy rare earth oxide is as follows:

[0046] (1) La(NO3)3, Ce(NO3)3, Nd(NO3)3, Sm(NO3)3, Gd(NO3)3, and Y(NO3)3 are weighed according to a molar ratio of 1:1:1:1:1:1, and then each rare earth nitrate is added to a mixed solvent of anhydrous ethanol and deionized water according to a ratio of 1 g:8 mL:60 mL, to obtain a mixed solution;

[0047] (2) Liquid ammonia is added to the mixed solution, and the molar ratio of nitrate to liquid ammonia in the mixed solution is 1:1.5, and stirring is performed at 400 r / min for 2 h, and the precipitate is obtained by suction filtration;

[0048] (3) The precipitate is mixed with n-pentanol according to a ratio of 1 g:15 mL, and rotary evaporation treatment is performed at 60°C, to obtain a precursor powder;

[0049] (4) The precursor is placed in an alumina crucible, and sintering is performed at 1000°C for 2 h by a muffle furnace, and the heating rate is 5°C / min, and after grinding, a high-entropy rare earth oxide with a particle diameter of 20 nm is obtained.

[0050] The specific preparation process of the modified modified potassium sodium water glass is as follows:

[0051] (a) Magnesium oxide is added to a toluene solution of 3-hydroxypropyltrimethoxysilane, and stirring is performed at a speed of 400 r / min for 11 h; after filtration, drying is performed at 80°C for 4 h, to obtain modified magnesium oxide; wherein the mass ratio of magnesium oxide to silane coupling agent is 11:1;

[0052] (b) Potassium silicate, sodium silicate, and modified magnesium oxide are added to deionized water, and stirring is performed at 70°C and a speed of 400 r / min for 1 h, to obtain modified potassium sodium water glass; wherein the mass ratio of potassium silicate, sodium silicate, and modified magnesium oxide is 100:20:0.8, the modulus of potassium silicate is 2.7, and the modulus of sodium silicate is 2.3.

[0053] Example 2 also provides a preparation method of the high-toughness high-strength steel basic welding rod, and taking a H785D type steel plate as an example, the specific preparation process is as follows:

[0054] The H785D steel plate is drawn and cut, polished, and cleaned with acetone to remove surface oil and rust to obtain a welding core; the liquid components of the coating are mixed evenly according to the ratio to obtain a binder; the solid components in the coating are mixed according to the ratio, and then the binder is added and stirred evenly to obtain a sticky coating; the sticky coating is extruded and coated on the welding core to form a coating, which is dried at room temperature and then dried, wherein the drying process is kept at 150°C for 1 hour, then heated to 250°C and kept for 1 hour, and then the furnace is cooled to room temperature to obtain a high-toughness and high-strength steel basic welding rod.

[0055] Example 3

[0056] Example 3 provides a high-toughness, high-strength steel basic welding rod, comprising a welding core and a coating covering the welding core; the coating is formed by mixing a solid component and a liquid component. The solid component comprises the following ingredients in parts by weight: 50 parts marble, 25 parts fluorite, 10 parts carbonate, 7 parts ferromanganese, 4 parts sodium fluoride, 2 parts phlogopite, and 2 parts high-entropy rare earth oxide; the liquid component is a binder, comprising the following raw materials in parts by weight: 78 parts modified potassium sodium water glass, 20 parts hydroxyethyl cellulose, and 2 parts lithium hydroxide. The liquid component accounts for 24% of the mass of the solid component. The welding core of the present invention can be composed of the same composition as the high-strength steel substrate.

[0057] The specific preparation process of the above-mentioned high entropy rare earth oxide is as follows:

[0058] (1) La(NO3)3, Ce(NO3)3, Nd(NO3)3, Sm(NO3)3, Gd(NO3)3, Y(NO3)3, and Er(NO3)3 were weighed in a molar ratio of 1:1:1:1:1:1:1, and then the raw materials of the rare earth nitrates were added to a mixed solvent of anhydrous ethanol and deionized water in a ratio of 1 g:10 mL:80 mL to obtain a mixed solution;

[0059] (2) adding liquid ammonia to the mixed solution, wherein the molar ratio of nitrate to liquid ammonia in the mixed solution is 1:2, stirring at 400 r / min for 1 h, and filtering to obtain a precipitate;

[0060] (3) The precipitate was mixed with n-pentanol at a ratio of 1 g:10 mL and subjected to rotary evaporation at 60°C to obtain a precursor powder;

[0061] (4) The precursor was placed in an alumina crucible and sintered at 1100°C for 3 h in a muffle furnace at a heating rate of 5°C / min. The high entropy rare earth oxide was taken out and ground to a particle diameter of 100 nm.

[0062] The specific preparation process of the modified potassium-sodium water glass is as follows:

[0063] (a) adding magnesium oxide to a toluene solution of 3-hydroxypropyltriethoxysilane at a stirring speed of 400 r / min for 12 h; drying the solution at 80° C. for 4 h to obtain modified magnesium oxide; wherein the mass ratio of magnesium oxide to silane coupling agent is 12:1;

[0064] (b) Potassium silicate, sodium silicate and modified magnesium oxide were added to deionized water and stirred at 70° C. and 400 rpm for 1 hour to obtain modified potassium-sodium water glass; wherein the mass ratio of potassium silicate, sodium silicate and modified magnesium oxide was 100:20:0.5, the modulus of potassium silicate was 2.9, and the modulus of sodium silicate was 2.5.

[0065] Example 3 also provides a method for preparing the high-toughness and high-strength steel basic welding rod. Taking H785D steel plate as an example, the specific preparation process is as follows:

[0066] H785D steel plates were drawn and cut, polished, and cleaned with acetone to remove surface oil and rust to obtain a welding core. The liquid components in the coating were mixed uniformly according to the weight ratio to obtain a binder. The solid components in the coating were mixed uniformly according to the ratio, and the binder was added to the mixed solid components and mixed uniformly to obtain a viscous coating. The viscous coating was extruded onto the welding core to form a coating. The coating was then dried and then dried at 150°C for 1 hour, then heated to 250°C for 1 hour, and then cooled to room temperature. This resulted in a high-toughness, high-strength basic steel welding rod.

[0067] (2) Comparative Example

[0068] Comparative Example 1

[0069] Comparative Example 1 is substantially the same as Example 1, except that the high entropy rare earth oxide in Example 1 is replaced by an equal amount of CeO2.

[0070] Comparative Example 2

[0071] Comparative Example 2 is basically the same as Example 1, except that the high entropy rare earth oxide in Example 1 is replaced by a mixture of equal amounts of La2O3 and CeO2, and the mass ratio of La2O3 to CeO2 is 1:1.

[0072] Comparative Example 3

[0073] Comparative Example 3 is substantially the same as Example 1, except that the modified magnesium oxide in Example 1 is replaced by an equal amount of magnesium oxide.

[0074] (3) Test examples

[0075] The properties of the basic welding rods prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were tested below.

[0076] The basic welding rods prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were used to weld H785D steel plates. The welding process parameters are shown in Table 1.

[0077] (1) Diffusible hydrogen content detection: After welding, the diffusible hydrogen content of each group of deposited metal is detected in accordance with GB / T3965-2012 "Determination of diffusible hydrogen in deposited metal".

[0078] (2) Mechanical properties: After welding, the yield strength, tensile strength, and elongation of each group of deposited metal were tested in accordance with GB / T2652-2008 “Tensile test methods for welds and deposited metals”. The results are shown in Table 3.

[0079] (3) Process performance: The welding process record is shown in Table 4.

[0080] Table 1 Deposited metal welding parameters

[0081] Welding specifications (mm) Welding current I(A) Welding voltage U(V) Welding speed (cm / min) Φ4.0 130～150 22～25 15～18

[0082] Table 2 Diffusible hydrogen content of deposited metal of welding rods in the embodiments of the present invention and comparative examples

[0083] Group Measured value mL / 100g Example 1 1.65 Example 2 1.63 Example 3 1.59 Comparative Example 1 2.31 Comparative Example 2 2.19 Comparative Example 3 1.69

[0084] Table 3 Mechanical properties of deposited metal of welding rods in the embodiments of the present invention and comparative examples

[0085] Group Yield strength ReL (MPa) Tensile strength Rm (MPa) Elongation A(%) Example 1 495 580 29 Example 2 501 585 30 Example 3 506 587 32 Comparative Example 1 468 553 22 Comparative Example 2 474 561 24 Comparative Example 3 482 570 28

[0086] Table 4 Welding process performance test results of welding rods

[0087]

[0088]

[0089] As can be seen from Tables 2 to 4, when the high-toughness and high-strength steel basic welding rods prepared in Examples 1 to 3 of the present invention are used for welding, the diffusible hydrogen content is low, the weld has excellent strength and toughness, and there is no tail red or coating cracking during welding, and the weld is well formed.

[0090] Compared to Example 1, Comparative Example 1 replaces the high-entropy rare earth oxide with CeO2, Comparative Example 2 replaces the high-entropy rare earth oxide with a mixture of equal amounts of La2O3 and CeO2, and Comparative Example 3 replaces the binder with a mixture of potassium-sodium water glass and magnesium oxide. When welding with the welding rods obtained in Comparative Examples 1 and 2, the diffusible hydrogen content increases significantly, and the strength and toughness of the weld deteriorate significantly. When welding with the welding rod obtained in Comparative Example 3, the process performance is poor, such as the appearance of red tail and spatter. Analysis of the reasons shows that the present invention adds high-entropy rare earth oxide particles to the welding rod coating. By subjecting the rare earth oxide to high-entropy treatment, its high-temperature stability can be improved, thereby inhibiting the desorption of diffusible hydrogen at welding temperatures. At the same time, the high-entropy rare earth oxide particles can refine the alloy structure of the weld and increase the content of metallic acicular ferrite in the weld, thereby significantly improving the toughness of the weld. In addition, by adding high-temperature resistant modified magnesium oxide to water glass and compounding it with hydroxyethyl cellulose and lithium hydroxide to prepare a binder, the high-temperature performance of the drug coating can be improved and the cracking of the drug coating at high temperatures can be inhibited. Hydroxyethyl cellulose also has good plasticity and flexibility, and can be emulsified into a film to block external moisture. When combined with water glass as a binder, it can slow down the moisture absorption rate of water glass, while reducing the brittleness of the drug coating, increasing the high-temperature stability of the drug coating, and improving the overall performance of the drug coating.

[0091] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the same. The basic principles and main features of the present invention have been described above using specific implementation schemes. Modifications or substitutions may be made based on the present invention, but such modifications or substitutions do not detract from the essence of the corresponding technical solutions from the scope of protection claimed by the present invention.

Claims

1. A high-toughness and high-strength steel basic welding rod, characterized by: The invention comprises a welding core and a coating, wherein the coating is formed by mixing a solid component and a liquid component; the solid component comprises the following raw materials in parts by weight: 42-50 parts of marble, 25-33 parts of fluorite, 7-10 parts of carbonate, 5-7 parts of ferromanganese, 4-5 parts of sodium fluoride, 2-3 parts of phlogopite, and 2-3 parts of high-entropy rare earth oxide; the liquid component is a binder, comprising the following raw materials in parts by weight: 78-82 parts of modified potassium sodium water glass, 17-20 parts of hydroxyethyl cellulose, and 1-2 parts of lithium hydroxide; the liquid component accounts for 21-24% of the mass of the solid component; The preparation method of the modified potassium-sodium water glass comprises the following steps: (a) adding magnesium oxide to a silane coupling agent solution, stirring to react, and drying to obtain modified magnesium oxide; (b) Potassium silicate, sodium silicate and modified magnesium oxide are added to water, heated and stirred to react, thereby obtaining modified potassium-sodium water glass.

2. The high-toughness and high-strength steel basic welding rod according to claim 1, characterized in that: The preparation method of the high entropy rare earth oxide comprises the following steps: (1) Weighing each rare earth nitrate raw material in an equal molar ratio, adding ethanol and water to dissolve them to obtain a mixed solution; (2) adding liquid ammonia to the mixed solution and stirring to react, and filtering to obtain a precipitate; (3) Mixing the precipitate with n-pentanol and performing rotary evaporation to obtain a precursor powder; (4) Sintering the precursor powder at 1000-1100° C. for 2-3 h and grinding the powder to obtain a high entropy rare earth oxide.

3. The high toughness and high strength steel basic welding rod according to claim 2, characterized in that: The particle size of the high entropy rare earth oxide is 20-100 nm.

4. The high toughness and high strength steel basic welding rod according to claim 2, characterized in that: The rare earth nitrate raw materials described in step (1) are selected from at least five of La(NO3)3, Ce(NO3)3, Nd(NO3)3, Sm(NO3)3, Gd(NO3)3, Y(NO3)3, and Er(NO3)3; the ratio of the total mass of the rare earth nitrate raw materials to ethanol and water is 1g: (5-10)mL: (50-80)mL; the temperature of the rotary evaporation in step (3) is 40-60°C.

5. The high toughness and high strength steel basic welding rod according to claim 2, characterized in that: The molar ratio of nitrate to liquid ammonia in the mixed solution in step (2) is 1:(1.5-2); the stirring reaction time is 1-2 hours; and the amount ratio of the precipitate to n-pentanol in step (3) is 1 g:(10-20) mL.

6. The high toughness and high strength steel basic welding rod according to claim 1, characterized in that: The silane coupling agent in step (a) is 3-hydroxypropyltrimethoxysilane or 3-hydroxypropyltriethoxysilane; the mass ratio of the magnesium oxide to the silane coupling agent is (10-12):1; the solvent of the silane coupling agent solution is toluene; the stirring time is 10-12 hours; the drying temperature is 80-90°C and the drying time is 4-5 hours.

7. The high toughness and high strength steel basic welding rod according to claim 1, characterized in that: The mass ratio of potassium silicate, sodium silicate, and modified magnesium oxide in step (b) is 100:(20-25):(0.5-1); the heating and stirring temperature is 50-70°C, and the time is 1-2 hours; the modulus of the potassium silicate is 2.7-2.9, and the modulus of the sodium silicate is 2.3-2.

5.

8. The method for preparing the high-toughness and high-strength steel basic welding rod according to any one of claims 1 to 7, characterized in that: The following steps are involved: The high-strength steel is drawn, cut, polished and cleaned to obtain a welding core; the liquid components in the coating are mixed uniformly according to the weight parts to obtain a binder; the solid components in the coating are mixed according to the weight parts, and then the binder is added and stirred uniformly to obtain a viscous coating; the viscous coating is applied to the welding core to form a coating, and the coating is dried and then baked to obtain a high-toughness and high-strength steel basic welding rod.

9. The method for preparing a high-toughness and high-strength steel basic welding rod according to claim 8, characterized in that: The drying process is as follows: first, the temperature is kept at 140-160° C. for 0.5-1.5 h, and then the temperature is raised to 240-260° C. and kept at this temperature for 0.5-1.5 h.

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