阅读说明：本技术 一种55公斤级耐候钢用焊条及其应用 (Welding rod for 55 kg-grade weathering steel and application thereof ) 是由 杨恒闯 续杰 陈成 汪涛 刘飞 刘�东 蔡俊 于 2020-12-09 设计创作，主要内容包括：本发明提供了一种55公斤级耐候钢用焊条,包括焊芯以及涂覆于焊芯表面的药皮,所述药皮由干粉和粘合剂混合而成,所述药皮中干粉的成分及各成分占干粉总质量的百分比如下：大理石35～40％,萤石15～20％,锆英砂3～5％,金红石3～8％,石英2～4％,硅铁3～6％,金属锰5～8％,镍粉4～8％,金属铬1～3％,铜粉1～3％,纯碱0.5～1.0％,Fe余量。该发明通过药皮向熔敷金属过渡适量的Ni、Cr、Cu及其他合金元素,使焊接金属具有优异的耐候性,其耐候指数I可大于6.5；同时通过对药皮组分的调整,控制焊缝金属中Mn、Si、C及其他合金元素的含量,保证熔敷金属抗拉强度高于550MPa,延伸率大于22％,-40℃低温冲击吸收能量大于60J。(The invention provides a welding rod for 55 kg-grade weathering steel, which comprises a core wire and a coating coated on the surface of the core wire, wherein the coating is formed by mixing dry powder and an adhesive, and the dry powder in the coating comprises the following components in percentage by mass of the total dry powder: 35-40% of marble, 15-20% of fluorite, 3-5% of zircon sand, 3-8% of rutile, 2-4% of quartz, 3-6% of ferrosilicon, 5-8% of manganese metal, 4-8% of nickel powder, 1-3% of chromium metal, 1-3% of copper powder, 0.5-1.0% of soda and the balance of Fe. According to the invention, a proper amount of Ni, Cr, Cu and other alloy elements are transferred from the coating to the deposited metal, so that the welding metal has excellent weather resistance, and the weather resistance index I can be more than 6.5; meanwhile, the contents of Mn, Si, C and other alloy elements in the weld metal are controlled by adjusting the components of the coating, so that the tensile strength of the deposited metal is higher than 550MPa, the elongation is more than 22%, and the low-temperature impact absorption energy at minus 40 ℃ is more than 60J.)

1. The welding rod for 55 kg-grade weathering steel comprises a core wire and a coating coated on the surface of the core wire, and is characterized in that the coating is formed by mixing dry powder and an adhesive, and the components of the dry powder and the percentages of the components in the coating in the total mass of the dry powder are as follows: 35-40% of marble, 15-20% of fluorite, 3-5% of zircon sand, 3-8% of rutile, 2-4% of quartz, 3-6% of ferrosilicon, 5-8% of manganese metal, 4-8% of nickel powder, 1-3% of chromium metal, 1-3% of copper powder, 0.5-1.0% of soda and the balance of Fe.

2. The welding rod for the 55 kg-grade weathering steel as claimed in claim 1, characterized in that the core wire is H08A core wire, the core wire accounts for 65-70% of the total mass of the welding rod, and the coating accounts for 30-35% of the total mass of the welding rod.

3. The welding electrode for weathering steel of 55 kg scale as set forth in claim 1, wherein CaO and CaF are contained in the coating₂The mass ratio of (0.3-0.8): 1; CaO and SiO₂The mass ratio of (8-12): 1.

4. the welding electrode for weathering steel of 55 kg grade as claimed in claim 1, wherein the binder is potassium sodium water glass.

5. The welding rod for the 55 kg-grade weathering steel as claimed in claim 1, characterized in that the components of the dry powder in the coating and the percentage of each component in the total mass of the dry powder are as follows: 35% of marble, 20% of fluorite, 5% of zircon sand, 3% of rutile, 4% of quartz, 6% of ferrosilicon, 5% of manganese metal, 8% of nickel powder, 3% of chromium metal, 2% of copper powder, 0.5% of soda and the balance of Fe.

6. The welding rod for the 55 kg-grade weathering steel as claimed in claim 1, characterized in that the components of the dry powder in the coating and the percentage of each component in the total mass of the dry powder are as follows: 40% of marble, 15% of fluorite, 3% of zircon sand, 6% of rutile, 2% of quartz, 4% of ferrosilicon, 6% of manganese metal, 7% of nickel powder, 1.5% of chromium metal, 1.5% of copper powder, 1.0% of soda and the balance of Fe.

7. The welding rod for the 55 kg-grade weathering steel as claimed in claim 1, characterized in that the components of the dry powder in the coating and the percentage of each component in the total mass of the dry powder are as follows: 36% of marble, 18% of fluorite, 4% of zircon sand, 5% of rutile, 3% of quartz, 3% of ferrosilicon, 8% of manganese metal, 4.5% of nickel powder, 1% of chromium metal, 3% of copper powder, 0.8% of soda and the balance of Fe.

8. The welding rod for the 55 kg-grade weathering steel as claimed in claim 1, characterized in that the components of the dry powder in the coating and the percentage of each component in the total mass of the dry powder are as follows: 37% of marble, 17% of fluorite, 4% of zircon sand, 7% of rutile, 2.5% of quartz, 5% of ferrosilicon, 6% of manganese metal, 6% of nickel powder, 2% of metal chromium, 1% of copper powder, 0.7% of soda and the balance of Fe.

9. The welding rod for the 55 kg-grade weathering steel as claimed in claim 1, characterized in that the components of the dry powder in the coating and the percentage of each component in the total mass of the dry powder are as follows: 38% of marble, 16% of fluorite, 3.5% of zircon sand, 8% of rutile, 2% of quartz, 4% of ferrosilicon, 7% of manganese metal, 5% of nickel powder, 1.5% of chromium metal, 2% of copper powder, 0.8% of soda ash and the balance of Fe.

10. The use of the welding rod for 55 kg weathering steel as claimed in any of claims 1 to 9, characterized in that the welding rod for 55 kg weathering steel is used for welding with a reverse DC power supply, the welding current is 160A, and the welding speed is 25.7 cm/min.

Technical Field

The invention belongs to the technical field of welding materials, and particularly relates to a welding rod for 55 kg-grade weathering steel and application thereof.

Background

The weathering steel has the capability of resisting atmospheric corrosion because a compact and stable protective oxide film is gradually formed on the surface in the using process of the weathering steel, and the oxide film prevents a corrosion medium from further permeating into the steel, so that the corrosion rate is greatly reduced. Corrosion not only causes damage to the structure, but also increases burdensome management and maintenance burden, and meanwhile, a large amount of manpower and capital are consumed for periodic coating. The trend of the resource-saving and environment-friendly society is that the demand for adopting weathering steel on structures such as bridge construction is higher and higher, and the development of welding materials matched with the weathering steel is more and more urgent.

At present, the corrosion-resistant steel welding rods on the market are few in variety, unstable in mechanical property and uneven in weather resistance. The corrosion resistance index I of weld metal is regulated to be not lower than 6.0 by referring to AWSD1.5, and at present, the weather resistance of a welding rod matched with weather-resistant steel with the tensile strength of 55 kilograms is rarely researched.

Disclosure of Invention

The invention aims to provide a welding rod for 55 kg-grade weathering steel, which solves the problem of unstable mechanical property of the existing corrosion-resistant steel welding rod, and ensures the corrosion resistance of the welding rod, so that the weathering index I is not lower than 6.5.

In order to achieve the purpose, the invention adopts the following technical scheme:

the welding rod for 55 kg-grade weathering steel comprises a core wire and a coating coated on the surface of the core wire, wherein the coating is formed by mixing dry powder and an adhesive, and the dry powder in the coating comprises the following components in percentage by mass of the total mass of the dry powder: 35-40% of marble, 15-20% of fluorite, 3-5% of zircon sand, 3-8% of rutile, 2-4% of quartz, 3-6% of ferrosilicon, 5-8% of manganese metal, 4-8% of nickel powder, 1-3% of chromium metal, 1-3% of copper powder, 0.5-1.0% of soda and the balance of Fe.

Further, the core wire is H08A core wire, the mass of the core wire accounts for 65-70% of the total mass of the welding rod, and the mass of the coating accounts for 30-35% of the total mass of the welding rod.

Further, CaO and CaF in the coating₂The mass ratio of (0.3-0.8): 1; CaO and SiO₂The mass ratio of (8-12): 1.

further, the adhesive adopts potassium-sodium water glass.

Specifically, the components of the dry powder in the coating and the percentage of each component in the total mass of the dry powder are as follows: 35% of marble, 20% of fluorite, 5% of zircon sand, 3% of rutile, 4% of quartz, 6% of ferrosilicon, 5% of manganese metal, 8% of nickel powder, 3% of chromium metal, 2% of copper powder, 0.5% of soda and the balance of Fe.

Specifically, the components of the dry powder in the coating and the percentage of each component in the total mass of the dry powder are as follows: 40% of marble, 15% of fluorite, 3% of zircon sand, 6% of rutile, 2% of quartz, 4% of ferrosilicon, 6% of manganese metal, 7% of nickel powder, 1.5% of chromium metal, 1.5% of copper powder, 1.0% of soda and the balance of Fe.

Specifically, the components of the dry powder in the coating and the percentage of each component in the total mass of the dry powder are as follows: 36% of marble, 18% of fluorite, 4% of zircon sand, 5% of rutile, 3% of quartz, 3% of ferrosilicon, 8% of manganese metal, 4.5% of nickel powder, 1% of chromium metal, 3% of copper powder, 0.8% of soda and the balance of Fe.

Specifically, the components of the dry powder in the coating and the percentage of each component in the total mass of the dry powder are as follows: 37% of marble, 17% of fluorite, 4% of zircon sand, 7% of rutile, 2.5% of quartz, 5% of ferrosilicon, 6% of manganese metal, 6% of nickel powder, 2% of metal chromium, 1% of copper powder, 0.7% of soda and the balance of Fe.

Specifically, the components of the dry powder in the coating and the percentage of each component in the total mass of the dry powder are as follows: 38% of marble, 16% of fluorite, 3.5% of zircon sand, 8% of rutile, 2% of quartz, 4% of ferrosilicon, 7% of manganese metal, 5% of nickel powder, 1.5% of chromium metal, 2% of copper powder, 0.8% of soda ash and the balance of Fe.

When the welding rod for the 55 kg-level weathering steel provided by the invention is used for welding, a direct current reverse connection type power supply is adopted for welding operation, the welding current is 160A, and the welding speed is 25.7 cm/min.

The design principle of the formula of the traditional Chinese medicine coating of the welding rod for 55 kg-grade weathering steel is as follows:

the traditional Chinese medicine coating adopts CaO-CaF₂-TiO₂-SiO₂The basic slag system can better deoxidize, dehydrogenate and desulfurize, has more stable performance, and determines the basic components and content of the coating through a large number of tests to improve the process performance of the basic welding rod.

A small amount of quartz is added into the coating, because SiO in the quartz₂The content of the (B) is higher, the alkalinity of the slag can be properly reduced, the fluidity of the slag is improved, the weld joint can be more attractive in forming, and the slag can be more easily removed. In order to improve the press coating performance of the welding rod, a small amount of soda ash is added into the coating to increase the lubricity of the coating. In order to improve the low-temperature impact toughness of weld metal, ferrosilicon and manganese metal are added into the coating for deoxidation, so that the oxygen content in the weld is reduced, and the harm of oxide inclusions to the low-temperature impact toughness is reduced; the Ni element can reduce the low-temperature brittle transition temperature and is very favorable for improving the low-temperature impact toughness. In order to improve the corrosion resistance, copper powder and metal chromium powder are added into the coating, Cr can form a compact oxidation film on the surface of steel, the electrode potential is improved, the passivation effect is generated, the corrosion resistance of the steel is improved, the increase of the Cu content has a certain refining effect on corrosion product particles, the compactness of a rust layer is favorably improved, the average corrosion depth and the corrosion rate of the weathering steel are effectively reduced, and the corrosion resistance of the steel is favorably improved.

In addition, the invention is characterized in that CaO and CaF in the coating are treated₂、SiO₂The proportion control ensures the welding process performance of the welding rod, namely when CaO and CaF are used₂The ratio of (0.3-0.8): 1, the electric arc is soft and has small splashing, and the welding can be carried out at all positions; in CaO and SiO₂The ratio of (8-12): 1, the molten pool has good fluidity and good air permeability, and is not easy to generate air holes.

The invention has the beneficial effects that:

(1) the welding rod for the 55 kg-grade weathering steel provided by the invention has the advantages that a proper amount of Ni, Cr, Cu and other alloy elements are transferred to deposited metal through a coating, so that the welded metal has excellent weather resistance, and the weather resistance index I can be more than 6.5.

(2) The welding rod for 55 kg-grade weathering steel provided by the invention controls the contents of Mn, Si, C and other alloy elements in weld metal by adjusting the components of the coating, ensures that the tensile strength of deposited metal is higher than 550MPa, the elongation is more than 22%, and the low-temperature impact absorption energy at minus 40 ℃ is more than 60J.

(3) The welding rod for 55 kg-grade weathering steel provided by the invention can be used for all-position welding, and has excellent welding process performance and attractive weld formation.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the embodiment, the mass of a welding core adopted by the welding rod for 55 kg-grade weathering steel accounts for 65-70% of the total mass of the welding rod, and the mass of a coating accounts for 30-35% of the total mass of the welding rod; the core wire adopts an H08A core wire, and the dry powder component proportion adopted by the coating in the corresponding embodiment is shown in Table 1, when the welding rod is manufactured, according to the manufacturing method of a common alkaline low-hydrogen welding rod, potassium sodium water glass is used as a bonding agent, and the uniformly mixed coating is uniformly pressed and coated on the surface of the core wire to manufacture the welding rod with the diameter of 4.0 mm.

Table 1: composition of dry powder in coating of each example (mass%)

Composition of dry powder	Example 1	Example 2	Example 3	Example 4	Example 5
						Marble	35	40	36	37	38
Fluorite	20	15	18	17	16
						Zircon sand	5	3	4	4	3.5
Rutile type	3	6	5	7	8
						Quartz	4	2	3	2.5	2
Silicon iron	6	4	3	5	4
						Manganese metal	5	6	8	6	7
Nickel powder	8	7	4.5	6	5
						Metallic chromium	3	1.5	1.0	2.0	1.5
Copper powder	2	1.5	3.0	1.0	2.0
						Soda ash	0.5	1.0	0.8	0.7	0.8
Iron powder	8.5	13	13.7	11.8	12.2

The physical and chemical properties of deposited metal were tested on 5 welding rods made of the welding rod powder of the above 5 examples, and the groove, size, sampling method and position of the test plate were all performed according to the Chinese national standard GB/T5117 "non-alloy steel and fine grain steel welding rod". And (3) adopting a direct-current reverse connection type power supply to carry out welding operation, wherein the welding current is 160A, and the welding speed is 25.7 cm/min.

The chemical components, weather resistance index I and mechanical properties of the deposited metal of the welding rod prepared in each example are shown in tables 2 and 3, wherein the weather resistance index I is calculated according to the following formula, and the chemical components are the chemical component contents of the deposited metal:

I＝26.01(％Cu)+3.88(％Ni)+1.20(％Cr)+1.48(％Si)+17.28(％P)-7.29(％Cu)×(％Ni)-9.10(％Ni)×(％P)-33.39(％Cu)²。

table 2: chemical components (mass percent) of deposited metal and weather resistance index I

Table 3: mechanical properties of deposited metal

In conclusion, the welding rod for the 55 kg-grade weathering steel provided by the invention has the advantages that a proper amount of Ni, Cr, Cu and other alloy elements are transferred to deposited metal through the flux coating, so that the welded metal has excellent weather resistance, and the weather resistance index I can be more than 6.5; meanwhile, the contents of Mn, Si, C and other alloy elements in the weld metal are controlled by adjusting the components of the coating, so that the tensile strength of the deposited metal is higher than 550MPa, the elongation is more than 22%, and the low-temperature impact absorption energy at minus 40 ℃ is more than 60J.

The above examples are merely illustrative of the present invention and should not be construed as limiting the scope of the invention, which is intended to be covered by the claims and any design similar or equivalent to the scope of the invention.