Steel-cored wire as well as preparation method and application thereof

Abstract

The invention provides a steel-cored wire and a preparation method and application thereof, and relates to the technical field of welding materials. The steel-cored welding wire comprises a steel belt and a steel core wrapped in the steel belt, and the steel core comprises the following components in percentage by mass: 16.00-18.00% of chromium, 1.00-1.00% of chromium, 1.00-1.00% of chromium, 1.00-1.00% of chromium, 1.00-1.00% of chromium, 1.00-1.00% of The content of nickel is 10.00%-14.00%; the molybdenum content is 2.00%-3.00%; the carbon content is less than or equal to 0.030%; the manganese content is less than or equal to 2.00%; the silicon content is less than or equal to 1.00%; the phosphorus content is less than or equal to 0.045%; the sulfur content is less than or equal to 0.030%; the nitrogen content is 0.7-0.9%, and the balance is iron and inevitable impurities. According to the steel-cored wire, during welding, the splashing rate can be effectively reduced, the generation probability of air holes is reduced, and meanwhile, the occurrence of hot cracks can be restrained. The escape of nitrogen is effectively inhibited, the welding manufacturability is good, the molten drop transition is more uniform during welding, the welding seam performance is more stable, and the mechanical performance is excellent.

Description

Technical Field

[0001] The present invention relates to the technical field of welding materials, and in particular to a steel core welding wire and a preparation method and application thereof. Background Art

[0002] High nitrogen austenitic stainless steel is a new type of steel that uses nitrogen (N) to replace the expensive nickel (Ni) as the main austenitizing element. The nitrogen element dissolved in steel has a high stacking fault energy, which can not only optimize the material's structure, but also greatly improve the material's mechanical properties. At the same time, high nitrogen austenitic stainless steel has many advantages such as low cost, high work hardening rate and good corrosion resistance.

[0003] However, during the welding process, high nitrogen austenitic stainless steel has the phenomenon of solid solution nitrogen element aggregation and escape, which leads to the decline of the performance of the welded joint. Therefore, weldability becomes a key factor restricting its promotion and application. It is worth noting that the nitrogen content in the welding wire has a significant effect on the welding stability of high nitrogen austenitic stainless steel. With the increase of nitrogen content, the fluctuation of electrical signals will intensify and the distribution will be discrete. In addition, the increase of nitrogen content will also make the shape of the molten droplet irregular and the size increase, resulting in the deterioration of the processability of the welding wire. When the nitrogen content of the welding wire is below 0.40%, the welding process stability is good, but the welding spatter rate will continue to increase with the increase of nitrogen content. The nitrogen loss caused by nitrogen escape can easily cause the high nitrogen austenitic stainless steel molten droplet to explode violently and produce a large amount of spatter, thereby forming joint pores, which greatly reduces the mechanical properties of the welded joint. Summary of the invention

[0004] In view of the above problems existing in the prior art, the present invention provides a steel core welding wire and a preparation method thereof, so as to improve the problem of accumulation and escape of dissolved nitrogen elements during welding of high nitrogen austenitic stainless steel.

[0005] To achieve the above-mentioned purpose and other related purposes, the first aspect of the present invention provides a steel core welding wire, the steel core welding wire comprising a steel strip and a steel core wrapped in the steel strip, the steel strip comprising the following components and the content of each component in terms of mass percentage of the steel strip: chromium content 16.00% to 18.00%, nickel content 10.00% to 14.00%, molybdenum content 2.00% to 3.00%, carbon content ≤0.030%, manganese content ≤2.00%, silicon content ≤1.00%, phosphorus content ≤0.045%; sulfur content ≤0.030%, The nitrogen content is 0.30% to 0.40%, and the balance is iron and inevitable impurities. The steel core includes the following components and the content of each component in terms of mass percentage: chromium content is 16.00% to 18.00%; nickel content is 10.00% to 14.00%; molybdenum content is 2.00% to 3.00%; carbon content is ≤0.030%; manganese content is ≤2.00%; silicon content is ≤1.00%; phosphorus content is ≤0.045%; sulfur content is ≤0.030%; nitrogen content is 0.7% to 0.9%, and the balance is iron and inevitable impurities.

[0006] In one embodiment of the present invention, the mass of the steel core is 80% to 85% of the total mass of the steel core welding wire.

[0007] In one embodiment of the present invention, the thickness of the steel strip is 0.2-0.4 mm, and the width of the steel strip is 10-14 mm.

[0008] In one embodiment of the present invention, the diameter of the steel core is 3.0-5.0 mm.

[0009] A second aspect of the present invention provides a method for preparing a steel core welding wire, comprising the following steps:

[0010] Rolling the steel strip into a U-shape;

[0011] Placing a steel core in a U-shaped steel belt, and closing the U-shaped steel belt to form a circle;

[0012] The steel strip filled with the steel core is drawn and reduced in diameter to a desired specification to obtain the steel core welding wire.

[0013] In one embodiment of the present invention, the diameter of the steel core welding wire is 1.2-1.6 mm.

[0014] A third aspect of the present invention provides a use of a steel core welding wire, wherein the steel core welding wire is suitable for welding high nitrogen austenitic stainless steel.

[0015] The steel core welding wire of the present invention uses a high nitrogen welding core as the steel core, and the steel strip is coated on the outside of the steel core. During the welding process, due to the skin effect of the current, the steel strip on the surface of the welding wire is melted first, and then the steel core is melted, and there is a certain melting time difference between the two. This feature can effectively inhibit the molten droplet transition during the welding of the high nitrogen austenitic stainless steel core, thereby reducing the occurrence of spatter, and at the same time can effectively control the overflow of nitrogen elements, thereby obtaining a deposited metal that meets the composition and performance requirements, and is suitable for high nitrogen austenitic stainless steel welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0017] Figure 1 FIG. 1 is a flow chart of the preparation of the steel core welding wire of the present invention in one embodiment. DETAILED DESCRIPTION

[0018] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the features in the following embodiments and the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific embodiments, rather than to limit the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are usually carried out under conventional conditions or according to the conditions recommended by the manufacturers.

[0019] When numerical ranges are given in the embodiments, it should be understood that unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are familiar to those skilled in the art and the description of the present invention, and any method, device and material of the prior art similar or equivalent to the method, device and material in the embodiments of the present invention can also be used to implement the present invention.

[0020] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" etc. used in this specification are only for the convenience of description and are not intended to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships, without substantially changing the technical content, should also be regarded as the scope of implementation of the present invention.

[0021] The present application provides a steel core welding wire, which comprises a steel strip and a steel core wrapped in the steel strip. The steel strip comprises the following components and the content of each component, measured by mass percentage of the steel strip: chromium content 16.00% to 18.00%, nickel content 10.00% to 14.00%, molybdenum content 2.00% to 3.00%, carbon content ≤0.030%, manganese content ≤2.00%, silicon content ≤1.00%, phosphorus content ≤0.045%; sulfur content ≤0.030%, nitrogen content 0.30% to 0. 40%, the balance being iron and inevitable impurities; the steel core comprises the following components and the content of each component, measured by mass percentage of the steel core: chromium content 16.00%-18.00%; nickel content 10.00%-14.00%; molybdenum content 2.00%-3.00%; carbon content ≤0.030%; manganese content ≤2.00%; silicon content ≤1.00%; phosphorus content ≤0.045%; sulfur content ≤0.030%; nitrogen content 0.7%-0.9%, the balance being iron and inevitable impurities.

[0022] In one embodiment, the mass of the steel core is 80% to 85% of the total mass of the steel core welding wire, for example, 80%, 83% or 85%, or any value within the range of 80% to 85%.

[0023] In one embodiment, the thickness of the steel strip is 0.2-0.4 mm, for example, the thickness of the steel strip is 0.2 mm, 0.3 mm, 0.4 mm, or any other value between 0.2 and 0.4 mm; the width of the steel strip is 10-14 mm, for example, any other value between 10 mm, 11 mm, 13 mm, or 14 mm.

[0024] In one embodiment, the diameter of the steel core is 3.0-5.0 mm, for example, the diameter of the steel core can be any value among 3 mm, 4 mm or 5 mm.

[0025] The steel core welding wire of the present application adopts a high nitrogen austenitic stainless steel core with a nitrogen content of about 0.8%. Due to its high nitrogen content, if the steel core material is used alone to produce welding wire for welding, under improper control, the porosity tendency of the weld joint will increase, and it will also show a high sensitivity to hot cracking. In the high nitrogen austenitic stainless steel welding process, when the weld is fully austenitic, it will show a very high sensitivity to hot cracking. The present invention reduces the sensitivity to hot cracking of welding by reasonably adjusting the content of other alloying elements in the steel strip so that a certain amount of high-temperature ferrite is produced in the weld. Therefore, the nitrogen content of the steel strip is between 0.3% and 0.4%. By adopting the design of steel strip wrapped around steel core to produce composite welding wire, during the welding process, with the help of the skin effect of the current, the steel strip on the surface of the welding wire is melted first, and then the steel core is melted. There is a certain melting time difference between the two, which can effectively inhibit the molten droplet transition during the welding of high-nitrogen austenitic stainless steel core, thereby reducing the occurrence of spatter. At the same time, the overflow of nitrogen elements can be effectively controlled, thereby obtaining a deposited metal that meets the composition and performance requirements, which meets the steel plate's demand for high nitrogen content in welding materials.

[0026] See also Figure 1 The present application also provides a method for preparing a steel core welding wire, comprising the following steps:

[0027] S1, rolling the steel strip into a U shape;

[0028] S2. Place the steel core in the U-shaped steel belt, and close the U-shaped steel belt to form a circle;

[0029] S3. The steel strip filled with the steel core is drawn and reduced in diameter to the required specifications to obtain the steel core welding wire.

[0030] In step S1, the steel strip includes the following components and the content of each component in terms of mass percentage of the steel strip: chromium content 16.00% to 18.00%, nickel content 10.00% to 14.00%, molybdenum content 2.00% to 3.00%, carbon content ≤0.030%, manganese content ≤2.00%, silicon content ≤1.00%, phosphorus content ≤0.045%; sulfur content ≤0.030%, nitrogen content 0.30% to 0.40%, and the remainder is iron and unavoidable impurities. Exemplarily, the thickness of the steel strip is 0.2 to 0.4 mm, for example, the thickness of the steel strip is any value of 0.2 mm, 0.3 mm or 0.4 mm, etc.; the width of the steel strip is 10 to 14 mm, for example, any value of 10 mm, 11 mm, 13 mm or 14 mm.

[0031] In step S2, the steel core includes the following components and the content of each component, measured by mass percentage of the steel core: chromium content 16.00% to 18.00%; nickel content 10.00% to 14.00%; molybdenum content 2.00% to 3.00%; carbon content ≤0.030%; manganese content ≤2.00%; silicon content ≤1.00%; phosphorus content ≤0.045%; sulfur content ≤0.030%; nitrogen content 0.7% to 0.9%, and the remainder is iron and unavoidable impurities.

[0032] In step S3, the diameter of the steel core welding wire is 1.2-1.6 mm, for example, any value among 1.2 mm, 1.4 mm or 1.6 mm.

[0033] The steel core welding wire prepared in this application can effectively reduce the spatter rate and the probability of pores during welding, and can also inhibit the occurrence of thermal cracks. The escape of nitrogen is effectively suppressed, the welding process is good, the droplet transition during welding is more uniform, the weld performance is more stable, and the mechanical properties are excellent, which is suitable for high nitrogen austenitic stainless steel welding.

[0034] The technical scheme of the present invention is described in detail below through several specific examples. Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available products, or can be prepared by conventional methods in the art, and the instruments used in the examples are all commercially available.

[0035] Example 1

[0036] The steel core welding wire of this embodiment includes a steel strip and a steel core wrapped in the steel strip. The steel strip includes the following components and the content of each component in terms of mass percentage of the steel strip: chromium content 16.00%, nickel content 13.00%, molybdenum content 3.00%, carbon content 0.030%, manganese content 1.8%, silicon content 0.80%, phosphorus content 0.045%; sulfur content 0.010%, nitrogen content 0.40%, and the balance is iron and unavoidable impurities; in terms of mass percentage of the steel core, the steel core includes the following The components and contents of each component are as follows: chromium content 17.00%; nickel content 13.00%; molybdenum content 2.50%; carbon content 0.020%; manganese content 2.00%; silicon content 0.70%; phosphorus content 0.043%; sulfur content 0.020%; nitrogen content 0.8%, and the balance is iron and inevitable impurities. The steel strip is rolled into a U shape; a steel core is placed in the U-shaped steel strip, and the U-shaped steel strip is seamed and formed into a circle; the steel strip filled with the steel core is drawn and reduced to the required specifications to obtain a steel core welding wire.

[0037] In this embodiment, the diameter of the steel core is 5.0 mm, the width of the steel strip is 14 mm, the thickness of the steel strip is 0.4 mm, the diameter of the steel core welding wire is 1.6 mm, and the mass of the steel core is 85% of the total mass of the steel core welding wire.

[0038] Example 2

[0039] The steel core welding wire of this embodiment includes a steel strip and a steel core wrapped in the steel strip. The steel strip includes the following components and the content of each component in terms of mass percentage of the steel strip: chromium content 18.00%, nickel content 14.00%, molybdenum content 2.00%, carbon content 0.020%, manganese content 2%, silicon content 0.90%, phosphorus content 0.044%; sulfur content 0.010%, nitrogen content 0.40%, and the balance is iron and unavoidable impurities; in terms of mass percentage of the steel core, the steel core includes the following components The steel strip is rolled into a U-shape; a steel core is placed in the U-shaped steel strip, and the U-shaped steel strip is joined to form a circle; the steel strip filled with the steel core is drawn and reduced to the required specification to obtain a steel core welding wire.

[0040] In this embodiment, the diameter of the steel core is 4.0 mm, the width of the steel strip is 12 mm, the thickness of the steel strip is 0.3 mm, the diameter of the steel core welding wire is 1.4 mm, and the mass of the steel core is 83% of the total mass of the steel core welding wire.

[0041] Example 3

[0042] The steel core welding wire of this embodiment includes a steel strip and a steel core wrapped in the steel strip. The steel strip includes the following components and the content of each component in terms of mass percentage of the steel strip: chromium content 18.00%, nickel content 10.00%, molybdenum content 2.50%, carbon content 0.025%, manganese content 1.7%, silicon content 1.00%, phosphorus content 0.044%; sulfur content 0.020%, nitrogen content 0.30%, and the balance is iron and unavoidable impurities; in terms of mass percentage of the steel core, the steel core includes: The following components and the contents of each component: chromium content 18.00%; nickel content 10.00%; molybdenum content 3.0%; carbon content 0.03%; manganese content 1.80%; silicon content 0.90%; phosphorus content 0.045%; sulfur content 0.020%; nitrogen content 0.70%, the balance is iron and inevitable impurities, the steel strip is rolled into a U shape; the steel core is placed in the U-shaped steel strip, the U-shaped steel strip is seamed and formed into a circle; the steel strip filled with the steel core is drawn and reduced to the required specifications to obtain the steel core welding wire.

[0043] In this embodiment, the diameter of the steel core is 3.0 mm, the width of the steel strip is 10 mm, the thickness of the steel strip is 0.2 mm, the diameter of the steel core welding wire is 1.2 mm, and the mass of the steel core is 81% of the total mass of the steel core welding wire.

[0044] Example 4

[0045] The steel core welding wire of this embodiment includes a steel strip and a steel core wrapped in the steel strip. The steel strip includes the following components and the content of each component in terms of mass percentage of the steel strip: chromium content 17.50%, nickel content 12.00%, molybdenum content 2.00%, carbon content 0.030%, manganese content 1.60%, silicon content 0.70%, phosphorus content 0.040%; sulfur content 0.025%, nitrogen content 0.35%, and the balance is iron and unavoidable impurities; in terms of mass percentage of the steel core, the steel core includes: The following components and the contents of each component: chromium content 16.50%; nickel content 14.00%; molybdenum content 2.8%; carbon content 0.025%; manganese content 1.60%; silicon content 0.70%; phosphorus content 0.040%; sulfur content 0.03%; nitrogen content 0.70%, the balance is iron and inevitable impurities, the steel strip is rolled into a U shape; the steel core is placed in the U-shaped steel strip, the U-shaped steel strip is seamed and formed into a circle; the steel strip filled with the steel core is drawn and reduced to the required specifications to obtain the steel core welding wire.

[0046] In this embodiment, the diameter of the steel core is 5.0 mm, the width of the steel strip is 14 mm, the thickness of the steel strip is 0.3 mm, the diameter of the steel core welding wire is 1.2 mm, and the mass of the steel core is 80% of the total mass of the steel core welding wire.

[0047] Example 5

[0048] The steel core welding wire of this embodiment includes a steel strip and a steel core wrapped in the steel strip. The steel strip includes the following components and the content of each component in terms of mass percentage of the steel strip: chromium content 17.00%, nickel content 12.00%, molybdenum content 2.50%, carbon content 0.021%, manganese content 1.80%, silicon content 0.80%, phosphorus content 0.045%; sulfur content 0.030%, nitrogen content 0.35%, and the balance is iron and unavoidable impurities; in terms of mass percentage of the steel core, the steel core includes: The following components and the contents of each component: chromium content 17.00%; nickel content 14.00%; molybdenum content 2.0%; carbon content 0.03%; manganese content 1.50%; silicon content 0.80%; phosphorus content 0.040%; sulfur content 0.015%; nitrogen content 0.90%, the balance is iron and inevitable impurities, the steel strip is rolled into a U shape; the steel core is placed in the U-shaped steel strip, the U-shaped steel strip is seamed and formed into a circle; the steel strip filled with the steel core is drawn and reduced to the required specifications to obtain the steel core welding wire.

[0049] In this embodiment, the diameter of the steel core is 4.0 mm, the width of the steel strip is 12 mm, the thickness of the steel strip is 0.2 mm, the diameter of the steel core welding wire is 1.4 mm, and the mass of the steel core is 80% of the total mass of the steel core welding wire.

[0050] Comparative Example 1

[0051] In this comparative example, the welding wire is a solid welding wire of uniform material. The chemical composition of the welding wire is as follows: chromium content 17.50%, nickel content 12.00%, molybdenum content 2.00%, carbon content 0.030%, manganese content 1.60%, silicon content 0.70%, phosphorus content 0.040%; sulfur content 0.025%, nitrogen content 0.8%, and the balance is iron and unavoidable impurities. The diameter of the welding wire in this comparative example is 1.2 mm.

[0052] Comparative Example 2

[0053] In this comparative example, the welding wire is a solid welding wire of uniform material. The chemical composition of the welding wire is as follows: chromium content 17.00%, nickel content 12.00%, molybdenum content 2.50%, carbon content 0.021%, manganese content 1.80%, silicon content 0.80%, phosphorus content 0.045%; sulfur content 0.030%, nitrogen content 0.65%, and the balance is iron and unavoidable impurities. The diameter of the welding wire in this comparative example is 1.4 mm.

[0054] Comparative Example 3

[0055] In this comparative example, the welding wire is a solid welding wire of uniform material. The chemical composition of the welding wire is as follows: chromium content 16.00%, nickel content 13.00%, molybdenum content 3.00%, carbon content 0.030%, manganese content 1.8%, silicon content 0.80%, phosphorus content 0.045%; sulfur content 0.010%, nitrogen content 0.70%, and the balance is iron and unavoidable impurities. The diameter of the welding wire in this comparative example is 1.6 mm.

[0056] Welding tests were carried out on the welding wires prepared in Examples 1 to 5 and Comparative Examples 1 to 3. According to the standard "GB / T29713-2013 Stainless Steel Welding Wire and Welding Strip", the chemical composition of the deposited metal was detected, and the mechanical properties of the welded joint were detected. The welding process performance and the nitrogen content of the deposited metal are shown in Table 1, and the mechanical properties of the welded joint are shown in Table 2:

[0057] Table 1: Welding process performance and nitrogen content of deposited metal of welding wires prepared in Examples 1 to 5 and Comparative Examples 1 to 3

[0058]

[0059] Table 2: Mechanical properties of welded joints using welding wires prepared in Examples 1 to 5 and Comparative Examples 1 to 3

[0060]

[0061] It can be seen from Table 1 that the steel core welding wire of the present application has good arc stability, small spatter, beautiful shape and stable nitrogen content.

[0062] The steel core welding wire of the present invention uses a high nitrogen welding core as the steel core, and the steel strip is coated on the outside of the steel core. During the welding process, due to the skin effect of the current, the steel strip on the surface of the welding wire is melted first, and then the steel core is melted, and there is a certain melting time difference between the two. This feature can effectively inhibit the molten droplet transition during the welding of the high nitrogen austenitic stainless steel core, thereby reducing the occurrence of spattering, and at the same time can effectively control the overflow of nitrogen elements, thereby obtaining a deposited metal that meets the composition and performance requirements, and is suitable for high nitrogen austenitic stainless steel welding. Therefore, the present invention effectively overcomes some practical problems in the prior art and has a high utilization value and use significance.

[0063] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A steel core welding wire, characterized in that: The steel core welding wire comprises a steel strip and a steel core wrapped in the steel strip. The steel strip comprises the following components and the content of each component, calculated by mass percentage of the steel strip: chromium content 16.00% to 18.00%, nickel content 10.00% to 14.00%, molybdenum content 2.00% to 3.00%, carbon content ≤0.030%, manganese content ≤2.00%, silicon content ≤1.00%, phosphorus content ≤0.045%; sulfur content ≤0.030%, nitrogen content 0.30% to 0.40%, The balance is iron and inevitable impurities; the steel core includes the following components and the content of each component in terms of mass percentage: chromium content 16.00% to 18.00%; nickel content 10.00% to 14.00%; molybdenum content 2.00% to 3.00%; carbon content ≤0.030%; manganese content ≤2.00%; silicon content ≤1.00%; phosphorus content ≤0.045%; sulfur content ≤0.030%; nitrogen content 0.7% to 0.9%, and the balance is iron and inevitable impurities.

2. The steel core welding wire according to claim 1, characterized in that: The mass of the steel core is 80% to 85% of the total mass of the steel core welding wire.

3. The steel core welding wire according to claim 1, characterized in that: The thickness of the steel strip is 0.2-0.4 mm, and the width of the steel strip is 10-14 mm.

4. The steel core welding wire according to claim 1, characterized in that: The diameter of the steel core is 3.0-5.0 mm.

5. A method for preparing the steel core welding wire according to any one of claims 1 to 4, characterized in that: The steps include: Rolling the steel strip into a U-shape; Placing a steel core in a U-shaped steel belt, and closing the U-shaped steel belt to form a circle; The steel strip filled with the steel core is drawn and reduced in diameter to a desired specification to obtain the steel core welding wire.

6. The preparation method according to claim 5, characterized in that: The diameter of the steel core welding wire is 1.2-1.6 mm.

7. Use of the steel core welding wire according to any one of claims 1 to 4, characterized in that: The steel core welding wire is suitable for welding high nitrogen austenitic stainless steel.

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