Flux-cored wire with high crack resistance and wear resistance and preparation method of flux-cored wire

Abstract

The invention discloses a flux-cored wire with high crack resistance and wear resistance and a preparation method of the flux-cored wire. The flux-cored wire comprises the following flux-cored raw materials in percentage by mass: 6-10% of electrolytic manganese; 28 to 34% of metal chromium; 0.5 to 1.5 percent of ferrotitanium; 1-4% of tungsten powder; 5-9% of nickel powder; 4-8% of 45 # ferrosilicon; 8 to 12% of colloidal graphene; 8-12% of molybdenum powder; and the balance of iron powder. According to the flux-cored wire, C, W, Cr, Mo and other elements are added into the flux core, the proportion of flux core powder is reasonably adjusted, and the flux-cored wire is suitable for surfacing continuous casting rollers, hot rolling rollers, shafts with the working temperature lower than 510 DEG C and sealing faces of medium-temperature and high-pressure stop valves and has the advantages of being high in heap melting speed, good in weldability, high in surface abrasion resistance, low in cost and the like. The hardness value of the steel plate can basically reach 50 HRC, and the steel plate has good crack resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of steel welding, and in particular relates to a highly crack-resistant and wear-resistant flux-cored welding wire and a preparation method thereof. Background Art

[0002] At present, the structure of my country's manufacturing industry is undergoing transformation and upgrading. China is transforming from a manufacturing power to a manufacturing power. The continuous development and innovation of wear-resistant technology are bringing major changes to the manufacturing industry, providing more flexible, efficient and sustainable manufacturing methods, and providing more possibilities for innovation and customized production. With the rapid development of industry, many mechanical equipment and components work in high-wear environments, such as mining machinery, construction machinery, metallurgical equipment, etc. In these scenarios, components are easily worn due to friction, and traditional materials are difficult to meet the wear resistance requirements. Welding wear-resistant material technology came into being. It can weld wear-resistant alloys on the surface of easily worn parts, so that the parts can obtain good wear resistance on the surface while maintaining the performance of the matrix. Early welding technology was relatively simple. With the advancement of science and technology, new welding methods continue to emerge, such as flux-cored arc welding, plasma arc surfacing, etc. These methods can more accurately control the welding process and improve the quality of the wear-resistant layer. However, the wear resistance and crack resistance of existing flux-cored welding wires need to be further improved. Summary of the invention

[0003] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a highly crack-resistant and wear-resistant flux-cored welding wire and a preparation method thereof. The flux-cored welding wire of the present invention is suitable for surfacing continuous casting rolls, hot rolling rolls and shafts with an operating temperature below 510°C, as well as the sealing surface of medium-temperature and high-pressure stop valves. It has a fast surfacing melting speed, good weldability, and strong surface wear resistance. Its hardness value can basically reach 50HRC and has good crack resistance.

[0004] The technical solution adopted by the present invention is as follows: A highly crack-resistant and wear-resistant flux-cored welding wire, the mass ratio of the welding wire flux-cored raw materials is:

[0005] Electrolytic manganese: 6-10%;

[0006] Metallic chromium: 28-34%;

[0007] Ferrotitanium: 0.5-1.5%;

[0008] Tungsten powder: 1-4%;

[0009] Nickel powder: 5-9%;

[0010] 45# ferrosilicon: 4-8%;

[0011] Colloidal graphene: 8-12%;

[0012] Molybdenum powder: 8-12%;

[0013] The remainder is iron powder.

[0014] The working principle of the welding wire core material added in the present invention is:

[0015] Metallic chromium: It mainly plays the role of alloying, which can improve the strength and hardness of the weld, and has red hardness and high-temperature oxidation resistance.

[0016] Nickel powder: Appropriate nickel powder can improve plastic toughness, but too high Ni content will increase hot cracking sensitivity.

[0017] Ti has a strong binding force with oxygen and has a stronger deoxidation ability than ferrosilicon, 2FeO+Ti→TiO2+2Fe. On the other hand, Ti can combine with N to reduce the gas in the weld metal.

[0018] Molybdenum powder: It mainly plays the role of alloying. Molybdenum powder is mainly added as an alloying agent to improve the hardenability and hardness of steel. The carbide formed is stronger than that of W and Cr.

[0019] Electrolytic manganese: Electrolytic manganese can be used as a deoxidizer. Appropriate manganese content is beneficial to the crack resistance of the molten metal.

[0020] Tungsten powder: It mainly plays the role of alloying, which can increase hardenability and form a strong and stable compound with carbon. Its hardness is second only to diamond.

[0021] 45# Ferrosilicon: In the process of additive melting, it mainly plays a deoxidation role. Silicon is chemically active and can graphitize metals.

[0022] Graphite: It is a key element to improve wear resistance and hardness. The carbide formed by graphite combined with Mo, Cr, W and V has better wear resistance than the compound combined with Mo, Cr, W, V and C element.

[0023] Iron powder: dilutes other elements and improves the melting efficiency as weld metal.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention reasonably designs the proportions of various powders in the flux core formula of the welding wire and adds elements such as C, W, Cr, and Mo to the flux core, so that the welding wire of the present invention has good welding processability and crack resistance, is suitable for enhancing the wear resistance of the surface of the base material, has fast melting speed, good weldability, strong surface wear resistance, and its hardness value can reach 50HRC and has good crack resistance.

[0026] 2. The raw materials used in the present invention are all high-grade raw materials with low content of S and P impurities, which is beneficial to improving the crack resistance of the molten metal.

[0027] As a preferred embodiment of the present invention, the diameter of the flux-cored welding wire is 0.8-1 mm. This solution uses a small-diameter welding wire to repair the surface of wear-resistant materials under small input conditions.

[0028] As a preferred embodiment of the present invention, the flux-cored welding wire is a metal powder flux-cored welding wire, which is welded by 75-85% Ar+CO2. This solution adopts 75-85% Ar+CO2 welding, which has uniform melting, beautiful weld shape, can realize continuous stacking, does not need slag cleaning, and improves welding efficiency during production.

[0029] As a preferred embodiment of the present invention, the metal chromium, ferrotitanium, tungsten powder, nickel powder, 45# ferrosilicon, colloidal graphene, and iron powder all use 140-220 mesh powder particles. In this solution, the powder particles use 140-220 mesh metal chromium, ferrotitanium, tungsten powder, nickel powder, 45# ferrosilicon, colloidal graphene, and iron powder as raw materials for flux-cored welding wire. These fine powder particles can enhance the wear resistance and crack resistance of the weld during welding, while optimizing the welding process performance, such as improving arc stability, reducing spatter and pores, and significantly improving the comprehensive performance of the welding wire.

[0030] As a preferred embodiment of the present invention, the flux-cored welding wire comprises a steel strip and a welding wire core, and the main chemical elements of the steel strip satisfy: C≤0.030, Mn≤0.6%, Si≤0.5%, P≤0.020%, S content≤0.020%, Ni≤0.6%, Mo≤0.5%, Cr:11.5-13.5%, Cu≤0.2%; the welding wire core accounts for 11.5-12.5% ​​of the total mass of the flux-cored welding wire.

[0031] In this scheme, the higher chromium content (11.5-13.5%) in the steel strip composition gives the welding wire good corrosion resistance and oxidation resistance, while controlling low sulfur and low phosphorus helps reduce welding defects and improve the toughness of the weld. The flux core accounts for 11.5-12.5% ​​of the total mass, which can provide stable welding process performance, such as stable arc, small spatter, and beautiful weld formation. In addition, the alloying elements in the flux core (such as nickel, molybdenum, etc.) can further optimize the mechanical properties and crack resistance of the weld. This flux-cored welding wire is suitable for a variety of welding processes and materials, with high deposition efficiency and good all-position welding capabilities.

[0032] The embodiment of the present invention also provides a method for preparing a highly crack-resistant and wear-resistant flux-cored welding wire, comprising the following steps:

[0033] S1: Pre-proportion and weigh the raw materials of the welding wire core, and the particle size of metal chromium, ferrotitanium, tungsten powder, nickel powder, 45# ferrosilicon, colloidal graphene, and iron powder is controlled within 140-220 meshes;

[0034] S2: Mix all the raw materials evenly and bake at 220-270℃, keep warm for 2-3h, wait for the powder to cool to no higher than 60℃ and stir for 30-60min;

[0035] S3: The powder is loaded into the welding wire steel strip at a filling rate of 11.5-12.5% ​​through the molding process, and five 20-30cm welding wires are cut for filling rate detection when the molding is off the line;

[0036] S4: Through the molding process, the uniformly mixed powder is filled into the welding wire steel strip at a filling rate of 11.5-12.5%, rolled into shape, and finely drawn to a specification of 0.8-1 mm.

[0037] Compared with the prior art, the beneficial effects of this solution are:

[0038] 1. By rationally designing the flux core formula of welding wire, adding wear-resistant enhancing ingredients such as metal chromium, titanium iron, tungsten powder, optimizing the proportion of various powders in the flux core formula, and adding elements such as C, W, Cr, Mo, etc. to the flux core, the welding wire can form a weld with high hardness and high wear resistance during the welding process, while significantly reducing the crack sensitivity of the weld.

[0039] 2. The flux core, which has been baked and stirred at 220-270℃, combined with strictly controlled filling rate and fine drawing process, ensures arc stability, low spatter and good slag removal during welding, improving welding quality and efficiency.

[0040] 3. The alloy elements and graphene in the flux core can improve the microstructure of the weld during the welding process, enhance the toughness and impact resistance of the weld, and make it suitable for welding scenarios with high strength and high wear resistance requirements. DETAILED DESCRIPTION

[0041] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions therein are essentially used as illustrations rather than to limit the present invention.

[0042] The flux-cored welding wire of the present invention is composed of a stainless steel SUS410L steel strip and a flux core. The steel strip has a specification of 0.4mm×10mm. The main chemical elements of the steel strip meet the following requirements: C≤0.030, Mn≤0.6%, Si≤0.5%, P≤0.020%, S content≤0.020%, Ni≤0.6%, Mo≤0.5%, Cr: 11.5-13.5%, Cu≤0.2%, and the flux core filling rate is 11.5-12.5%.

[0043] Examples 1-3

[0044] The flux core proportions of the welding wires of Examples 1-3 of the present invention are shown in Table 1.

[0045] The method for preparing a highly crack-resistant and wear-resistant flux-cored welding wire according to an embodiment of the present invention comprises the following steps:

[0046] S1: Pre-proportion and weigh the raw materials of the welding wire core, and the particle size of metal chromium, ferrotitanium, tungsten powder, nickel powder, 45# ferrosilicon, colloidal graphene, and iron powder is controlled within 140-220 meshes;

[0047] S2: Mix all the raw materials evenly and bake at 220-270℃, keep warm for 2-3h, wait for the powder to cool to no higher than 60℃ and stir for 30-60min;

[0048] S3: Through the molding process, the powder is loaded into the welding wire steel strip at a filling rate of 11.5-12.5%, and five 20-30cm welding wires are cut for filling rate detection when the molding line is off;

[0049] S4: Through the molding process, the uniformly mixed powder is filled into the welding wire steel strip at a filling rate of 11.5-12.5%, rolled into shape, and finely drawn to a specification of 0.9 mm.

[0050] Table 1 Welding wire flux core ratio of Examples 1-3

[0051] Core ratio Example 1 Example 2 Example 3 Electrolytic manganese: 6-10% 6 8 10 Metallic chromium: 28-34% 28 31 34 Ferrotitanium: 0.5-1.5% 1.5 1 0.5 Tungsten powder: 1-4% 1 2.5 4 Nickel powder: 5-9% 5 7 9 45# Ferrosilicon: 4-8% 4 6 8 Colloidal graphene: 8-12% 12 10 8 Molybdenum powder: 8-12% 12 10 8 Iron Fan The balance is iron powder The balance is iron powder The balance is iron powder

[0052] Heap melting test:

[0053] The wear-resistant metal powder cored flux-cored welding wire obtained in the above Examples 1-3 was subjected to a fusion test, using 75-85% Ar+CO2 gas shielded welding. The test results of the chemical composition (mass fraction %) in the fusion metal are shown in Table 3.

[0054] Table 3 Chemical composition content in Examples 1-3

[0055] Chemical Elements C Mn Si S P Cr Ni Mo Example 1 0.155 0.84 0.44 0.03 0.05 14.65 0.68 1.01 Example 2 0.175 0.86 0.50 0.004 0.05 14.9 0.75 1.12 Example 3 0.182 0.95 0.55 0.004 0.06 15.2 0.8 1.23

[0056] Table 4 Surface hardness of molten metal

[0057] Example HRC Example 1 53 48 52 Example 2 47 54 55 Example 3 50 54 53

[0058] It can be seen from Table 4 that the hardness value of the molten metal obtained by the wear-resistant metal powder core flux core of this embodiment is good and the value is stable.

[0059] In addition, the molten metal obtained in the above Examples 1-3 was subjected to a radiographic flaw detection test, and the result was Level I.

[0060] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A highly crack-resistant and wear-resistant flux-cored welding wire, characterized in that: The mass ratio of welding wire core raw materials is: Electrolytic manganese: 6-10%; Metallic chromium: 28-34%; Ferrotitanium: 0.5-1.5%; Tungsten powder: 1-4%; Nickel powder: 5-9%; 45# ferrosilicon: 4-8%; Colloidal graphene: 8-12%; Molybdenum powder: 8-12%; The remainder is iron powder.

2. A highly crack-resistant and wear-resistant flux-cored welding wire according to claim 1, characterized in that: The diameter specification of the flux-cored welding wire is 0.8-1 mm.

3. A highly crack-resistant and wear-resistant flux-cored welding wire according to claim 2, characterized in that: The flux-cored welding wire is a metal powder type flux-cored welding wire, which is welded by 75-85% Ar+CO2.

4. The method #1 according to claim 3, characterized in that: The metal chromium, titanium iron, tungsten powder, nickel powder, 45# ferrosilicon, colloidal graphene and iron powder all adopt 140-220 mesh powder particles.

5. The highly crack-resistant and wear-resistant flux-cored welding wire according to claim 4, characterized in that: The flux-cored welding wire comprises a steel strip and a welding wire flux core. The main chemical elements of the steel strip meet the following requirements: C≤0.030, Mn≤0.6%, Si≤0.5%, P≤0.020%, S content≤0.020%, Ni≤0.6%, Mo≤0.5%, Cr: 11.5-13.5%, Cu≤0.2%; the welding wire flux core accounts for 11.5-12.5% ​​of the total mass of the flux-cored welding wire.

6. The method for preparing a highly crack-resistant and wear-resistant flux-cored welding wire according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: Pre-proportion and weigh the raw materials of the welding wire core, and the particle size of metal chromium, ferrotitanium, tungsten powder, nickel powder, 45# ferrosilicon, colloidal graphene, and iron powder is controlled within 140-220 meshes; S2: Mix all the raw materials evenly and bake at 220-270℃, keep warm for 2-3h, wait for the powder to cool to no higher than 60℃ and stir for 30-60min; S3: Through the molding process, the powder is loaded into the welding wire steel strip at a filling rate of 11.5-12.5%. When the molding is off the line, five 20-30cm welding wires are cut to test the filling rate; S4: Through the molding process, the uniformly mixed powder is filled into the welding wire steel strip at a filling rate of 11.5-12.5%, rolled into shape, and finely drawn to a specification of 0.8-1mm.