High-strength steel welding wire with tensile strength larger than 1000 Mpa as well as preparation method and application of high-strength steel welding wire

Abstract

The invention discloses a high-strength steel welding wire with the tensile strength larger than 1000 Mpa and a preparation method and application of the high-strength steel welding wire, and belongs to the technical field of welding materials and preparation of the welding materials. According to the method, a two-connection type three-roller roller die drawing technology is adopted, the pass area reduction rate and the drawing advancing speed are reasonably controlled, annealing-free ultra-large area reduction rate stable wire drawing is achieved, the tensile strength of the welding wire is uniform and stable, the welding material can have the high yield strength which cannot be achieved through an existing welding material preparation technology, and the welding quality is improved. And the wire feeding stability during welding wire welding is further improved while non-annealing high-speed continuous drawing is realized. In addition, procedures are effectively simplified, welding wire production efficiency is improved, production energy consumption is reduced, and high industrial value is achieved.

Description

Technical Field

[0001] The invention relates to a high-strength steel welding wire with a tensile strength greater than 1000Mpa and a preparation method and application thereof, belonging to the technical field of welding materials and preparation thereof. Background Art

[0002] The existing high-strength low-alloy gas shielded welding wire with a tensile strength greater than 1000Mpa is produced by the traditional fixed-eye die drawing technology. This process has a series of problems such as friction between the contact surface of the die and the wire rod and the accompanying heat effect, which affect the quality of the drawn product. Since the alloy content of high-strength steel welding wire with a tensile strength greater than 1000Mpa is relatively high, the original wire rod has high strength, and the work hardening phenomenon is serious during the die drawing process. When the wire rod is drawn to a certain deformation amount, it will cause serious embrittlement and frequent wire breakage. In order to successfully complete the production, two or three annealing treatments are required, but oxidation, nitridation and inconsistent annealing effects are inevitably generated during the annealing process. Oxidation and nitridation will increase the O and N content in the welding wire and reduce the performance of the welding wire. Inconsistent annealing effects will lead to uneven stress distribution in the length direction of the welding wire and affect the processability of the welding wire, thereby seriously affecting the quality stability of the welding wire.

[0003] For example, in patent CN107252997 A: oxidation, nitridation and uneven annealing will inevitably occur during the annealing process. Oxidation and nitridation will increase the content of O and N in the welding wire, reduce the performance of the welding wire, and uneven annealing will seriously affect the stability of the welding wire quality. In patent CN 109647916 A: pickling and boronization will cause unstable surface quality. Its production process cannot achieve continuous drawing, and the wire diameter is not less than 2.0mm, and it is impossible to achieve non-annealing drawing to the 1.2mm wire diameter specification commonly used in gas shielded welding. In addition, the die-drawing sizing process destroys the law of continuous strengthening of yield strength with deformation during roller drawing, and the yield strength drops sharply, which is not conducive to high-speed drawing and wire feeding during welding.

[0004] In addition, copper-plated welding wire produces a large amount of copper fume during welding. Inhalation of copper fume can cause metal fume fever, chills, fever, respiratory irritation, and long-term inhalation can cause lung fibrosis, which is extremely harmful to the health of users. Copper-plated welding wire produces a large amount of waste liquid during the copper plating process, which not only increases environmental protection expenses and production costs, but also is inconsistent with the "low-carbon production" concept promoted by modern production. Therefore, it is very necessary to provide a method for preparing a non-copper-plated high-strength steel gas shielded welding wire with a tensile strength greater than 1000Mpa without annealing treatment. Summary of the invention

[0005] In view of the above-mentioned technical problems existing in the existing method for preparing high-strength steel welding wire, the present invention provides a high-strength steel welding wire with a tensile strength greater than 1000Mpa, a preparation method thereof and an application thereof.

[0006] The technical solution of the present invention:

[0007] One of the purposes of the present invention is to provide a method for preparing a high-strength steel welding wire, the method comprising the following steps:

[0008] (1) Surface treatment is performed on high-strength steel wire rod to obtain pre-drawn wire rod;

[0009] (2) subjecting the pre-drawn wire rod to roller die diameter reduction drawing to obtain high-strength steel wire;

[0010] (3) The high-strength steel wire is oiled, wound and packaged to obtain high-strength steel welding wire.

[0011] It is further defined that the surface treatment in (1) is to sequentially unwind, peel, straighten and grind the high-strength steel wire rod, remove the oxide scale and impurities on the surface of the high-strength steel, and then retract the roller to obtain the pre-drawn wire rod.

[0012] It is further defined that the high-strength steel wire rod is composed of hot-rolled high-strength steel with a diameter of 5.5 mm and a tensile strength greater than 1000 MPa.

[0013] It is further defined that the tensile strength of high-strength steel wire rod is 1080-1150 MPa.

[0014] It is further defined that (2) the middle roller die diameter reduction drawing is carried out by a combined die roller to establish a round hole type two-roller Y-type three-roller die, the two-roller three-roller die has two roll groups, the two roll groups are staggered, and the staggered angle is 60°; each roll group consists of three rolls, the three rolls are arranged in a Y shape, and the angle between adjacent rolls is 120°.

[0015] It is further defined that the high-strength steel wire obtained in (2) has a diameter of 1.18 mm.

[0016] It is further defined that (2) the forward speed of the roller die reducing drawing process is not greater than 15 mm / s.

[0017] It is further defined that (2) the number of roller die diameter reducing drawing passes is 12, and the surface reduction rate decreases gradually with each pass.

[0018] It is further defined that the pass reduction rate is (compared with the original area) 24%→42%→54%→64%→73%→79%→85%→89%→91.5%→94%→94.5%→95%.

[0019] It is further defined that in (3), anti-rust oil is coated on the surface of the high-strength steel wire.

[0020] The second object of the present invention is to provide a high-strength steel welding wire with a tensile strength greater than 1000Mpa obtained by the above preparation method.

[0021] Further limiting is that high-strength steel welding wire with a tensile strength greater than 1000Mpa is used for gas shielded welding.

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

[0023] (1) The preparation process of the high-strength steel welding wire with a tensile strength greater than 1000Mpa provided by the present invention does not require pickling, boronization, annealing and softening, die cold drawing and other process steps that have a non-positive impact on the composition, structure and surface quality of the welding material. The yield strength and tensile strength of the welding material can be increased or decreased synchronously by controlling the cold plastic deformation process of the welding material, so that the obtained welding wire has a high yield strength, is uniform and stable, and has high surface quality and excellent wire feeding performance.

[0024] (2) The present invention adopts a two-stage three-roller die drawing technology, and by reasonably controlling the surface reduction rate and the drawing forward speed, it can achieve continuous drawing with a surface reduction rate of more than 95% without annealing in the middle of drawing, simplify the process, improve the welding wire production efficiency, reduce production energy consumption, and avoid the uneven performance of the wire rod caused by intermediate annealing, effectively ensuring the consistency of the finished welding wire and the stability of the surface quality and the yield rate. And by controlling the diameter reduction ratio, the yield strength of the finished welding wire can be effectively controlled, making the welding wire more conducive to wire feeding during welding.

[0025] (3) The high-strength steel welding wire preparation process of the present invention can reduce the wire rod from 5.5 mm in diameter to 1.18 mm in diameter in 12 passes at one time. The pass reduction rate is designed to be gradually reduced, so that the yield strength shows a continuous strengthening law with deformation, which is beneficial to the drawing of the welding wire, and the finished welding wire is conducive to wire feeding during welding.

[0026] (4) The high-strength steel welding wire prepared by the present invention does not need to be copper-plated, and can meet the wire feeding requirements of gas-shielded welding wire. It is safe and environmentally friendly, and avoids the mold diameter reduction process in the copper plating process that destroys the law that the yield strength of the welding wire increases with the deformation amount. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a scatter plot of the changes in tensile strength and yield strength during the preparation of high-strength steel welding wire in Example 1;

[0028] Figure 2 This is a scatter plot of the changes in tensile strength and yield strength during the preparation of high-strength steel welding wire in Comparative Example 1. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0032] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained through commercial channels by those skilled in the art.

[0033] Example 1

[0034] In this embodiment, a low-alloy steel wire rod for hydropower with a tensile strength of 1080-1150 MPa and a diameter of 5.5 mm in a hot-rolled state is processed into a 1000 MPa-grade low-alloy steel gas shielded welding wire for hydropower with a diameter of 1.18 mm. The preparation method is carried out according to the following steps:

[0035] (1) a 5.5 mm diameter low alloy steel wire rod for hydropower is subjected to wire laying, shelling, straightening, grinding and polishing treatments in sequence, and the oxide scale and impurities on the surface of the high-strength steel are removed and then rolled to obtain a pre-drawn wire rod;

[0036] Specifically, a Ф5.5mm low-alloy steel wire rod for hydropower is connected to a mechanical shelling device from a pay-off stand to pretreat the oxide scale on the surface of the welding wire and straighten the wire rod at the same time. The surface of the wire rod is then deeply ground and polished by a sanding machine to remove the oxide scale and debris attached to it.

[0037] (2) subjecting the pre-drawn wire rod to roller die diameter reduction drawing to obtain high-strength steel wire;

[0038] Specifically, the pre-drawn wire rod is continuously reduced in diameter by using a two-roll Y-type three-roll roller die with a round hole formed by a combined die roller. The pre-drawn wire rod is continuously drawn to a finished product at one time. The maximum forward speed of the roller die drawing is 15mm / s. The pre-drawn wire rod is directly drawn from Ф5.5mm to Ф1.18mm. The roller die diameter reduction drawing passes are 12 passes, and the pass reduction rate gradually decreases. The specific pass reduction rate is (compared with the original area) 24%→42%→54%→64%→73%→79%→85%→89%→91.5%→94%→94.5%→95%. The two-roll three-roll roller die has two roller groups, the two roller groups are staggered, and the staggered angle is 60°; each roller group consists of three rollers, the three rollers are Y-shaped, and the angle between adjacent rollers is 120°. The tensile strength and yield strength were characterized at the area reduction ratios of 95%, 94%, 79%, 64% and 0%. Figure 1 As shown. Figure 1 It can be seen that without heat treatment during the drawing process, the purpose of large area reduction drawing can be achieved by controlling the cold plastic deformation of the weld material only through roller pulling, and the yield strength and tensile strength of the weld material can be increased simultaneously.

[0039] (3) cleaning, oiling, winding and packaging the high-strength steel wire to obtain high-strength steel welding wire;

[0040] The high-strength steel wire is cleaned to remove impurities such as lubricants on the surface of the welding wire, and a certain thickness of anti-rust oil is applied to the surface of the welding wire through a device. Finally, it is wound and packaged to obtain high-strength steel welding wire.

[0041] Comparative Example 1

[0042] The difference between this comparative example and Example 1 is that in step (2), a conventional fixed die is used to reduce the diameter of the pre-drawn wire rod to obtain a high-strength steel wire, and the remaining operation process and parameter settings are the same as those in Example 1. The specific preparation method is carried out according to the following steps:

[0043] (1) a 5.5 mm diameter low alloy steel wire rod for hydropower is subjected to wire laying, shelling, straightening and grinding and polishing treatments in sequence, and the oxide scale and impurities on the surface of the high strength steel wire rod are removed and then rolled to obtain a pre-drawn wire rod;

[0044] Specifically, a Ф5.5mm low-alloy steel wire rod for hydropower is connected to a mechanical shelling device from a pay-off stand to pretreat the oxide scale on the surface of the welding wire and straighten the wire rod at the same time. The surface of the wire rod is then deeply ground and polished by a sanding machine to remove the oxide scale and debris attached to it.

[0045] (2) subjecting the pre-drawn wire rod to conventional fixed die diameter reduction drawing to obtain high-strength steel wire;

[0046] Specifically, the pre-drawn wire rod is drawn by a fixed die with a maximum forward speed of 12 mm / s, and the pre-drawn wire rod is drawn from Ф5.5 mm to Ф1.18 mm. The roller die diameter reduction drawing passes are 14 passes, and the pass reduction rates are (compared with the original area) 27% → 47% → 57% → 64% → 70% → 75% → 79% → 84% → 87% → 89% → 91.5% → 94% → 94.5% → 95%. Annealing is carried out at a reduction rate of 0% and 79%, the annealing temperature is 1050°C, and annealing is carried out on a continuous annealing line. The tensile strength and yield strength are characterized at a reduction rate of 95%, 94%, 79%, 64% and 0%, and the results are as follows Figure 2 shown.

[0047] (3) cleaning, oiling, winding and packaging the high-strength steel wire to obtain high-strength steel welding wire;

[0048] The high-strength steel wire is cleaned to remove impurities such as lubricants on the surface of the welding wire, and a certain thickness of anti-rust oil is applied to the surface of the welding wire through a device. Finally, it is wound and packaged to obtain high-strength steel welding wire.

[0049] contrast Figure 1 and Figure 2 It can be seen that under the same area reduction rate, the tensile strength of the welding wire obtained by roller drawing and die drawing is not much different, but the yield strength is very different. The welding wire drawn by reducing roller die is less likely to yield, which is conducive to high-speed drawing during production and more beneficial to wire feeding during welding.

[0050] Further comparison of the yield rate showed that the yield rate of roller die continuous drawing was 97.2%, and the yield rate of fixed die drawing was 92.5%.

[0051] Further comparison of production efficiency showed that when a bundle of wire rods is 2 tons, the fastest cycle for producing 2 tons of welding wire using roller die continuous drawing is 10 hours, and the fastest cycle for producing 2 tons of welding wire using fixed die drawing (including two annealing and cooling times) is 42 hours.

[0052] Further comparison of energy consumption shows that roller die drawing consumes 1560kW·h of electricity to produce 2 tons of welding wire, while fixed die drawing consumes 1810kW·h of electricity to produce 2 tons of welding wire.

[0053] In summary, the present invention effectively overcomes the shortcomings of the prior art and has high industrial value.

[0054] Although the present invention has been disclosed as above in the preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A method for preparing a high-strength steel welding wire, characterized in that: include: (1) Surface treatment is performed on high-strength steel wire rod to obtain pre-drawn wire rod; (2) subjecting the pre-drawn wire rod to roller die diameter reduction drawing to obtain high-strength steel wire; (3) The high-strength steel wire is cleaned, oiled, wound and packaged to obtain high-strength steel welding wire.

2. The preparation method according to claim 1, characterized in that: (1) The surface treatment is to sequentially unwind the high-strength steel wire rod by wire laying, shelling, straightening, and grinding and polishing, remove the oxide scale and impurities on the surface of the high-strength steel, and then retract the roller to obtain the pre-drawn wire rod.

3. The preparation method according to claim 1, characterized in that: The high-strength steel wire rod is made of hot-rolled high-strength steel with a diameter of 5.5mm and a tensile strength greater than 1000Mpa.

4. The preparation method according to claim 1, characterized in that: The tensile strength of high-strength steel wire rod is 1080~1150Mpa.

5. The preparation method according to claim 1, characterized in that: (2) The middle roller die diameter reduction drawing is carried out by a combined die roll to establish a round hole type two-roller Y-type three-roller die. The two-roller three-roller die has two roll groups, and the two roll groups are staggered with an angle of 60°; each roll group consists of three rolls, and the three rolls are arranged in a Y shape, with an angle of 120° between adjacent rolls.

6. The preparation method according to claim 1, characterized in that: (2) The high-strength steel wire material has a diameter of 1.18 mm.

7. The preparation method according to claim 1, characterized in that: (2) The forward speed of the middle roller die reducing drawing shall not exceed 15 mm / s.

8. The preparation method according to claim 1, characterized in that: (2) The number of roller die diameter reduction drawing passes is 12, and the surface reduction rate decreases gradually with each pass.

9. A high-strength steel welding wire having a tensile strength greater than 1000 MPa obtained by the preparation method according to any one of claims 1 to 8.

10. An application of the high-strength steel welding wire according to claim 9, characterized in that: Used for gas shielded welding.

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