Self-stripping slag all-position welding gas shielded solid wire rod and welding wire

Abstract

The application discloses a gas shield solid wire rod and welding wire for improving full-position welding arc stability, which contains Fe and inevitable impurity elements, and the following chemical elements with mass percentage: C: 0.05-0.12%; Si: 0.7-1.4%; Mn: 1.0-1.9%; S: 0.008-0.02%; Ti: 0.08-0.19%; Al: 0.01-0.08%; Zr: 0.01-0.06%; Ni: 0.1-0.8%; Mo: 0.09-0.25%; Y: 0.02-0.07%; O: 0.003-0.008%. The welding wire can realize uniform distribution and spreading of the bead surface layer slag to both sides of the weld and self-stripping after welding, and avoids the problem of arc instability caused by a large amount of slag gathering in the center of the weld.

Description

Technical Field

[0001] This invention relates to a welding wire rod and welding wire, and more particularly to a gas-shielded solid welding wire rod and welding wire. Background Technology

[0002] Solid wire gas metal arc welding is a commonly used welding method in the construction of various engineering structures. Its equipment technology is mature and stable, easy to operate, efficient and low cost. With appropriate matching of welding materials and application of welding process specifications, welded joints with good welding quality and comprehensive performance can be obtained.

[0003] In the manufacturing process of specific industrial welded structures, complex spatial welding positions are often involved, such as all-position welding of pipelines, welding of energy medium storage tanks and spherical tanks in complex spatial positions, and vertical and overhead welding of important steel structures. In these cases, the weld droplets and molten pool, under the influence of gravity, exhibit different transition modes and forming characteristics compared to flat and horizontal welding. The stability of the welding arc often plays a crucial role in the normal transition of the molten droplets. Any factor that is detrimental to the stability of the welding arc will affect the stability and uniformity of the droplet transition, thereby adversely affecting the welding quality.

[0004] Many factors influence the stability of welding arcs. Currently, more attention is paid to the ease with which the gas medium in the arc region ionizes. This is achieved by adjusting the composition of the welding shielding gas and adding chemical elements with low vapor pressure and low ionization voltage to the welding wire, thereby improving arc stability. However, the problem of decreased conductivity and reduced arc stability caused by the thin layer of weld slag formed on the weld surface has not been identified.

[0005] For example, Chinese patent document CN 106475708A, published on March 8, 2017, entitled "A Gas-Shielded Solid Welding Wire for Welding Steel Ring Welds in X80 Pipelines," discloses a gas-shielded solid welding wire for welding steel ring welds in X80 pipelines. Its chemical composition by mass percentage is: C: 0.05%-0.10%; Si: 0.70%-1.00%; Mn: 1.45%-1.75%; P < 0.010%; S < 0.005%; Cr: 0.40%-0.60%; Ti: 0.06%-0.10%; Ni: 0.90%-1.10%; with the balance being Fe. However, this design does not address the issue of decreased conductivity caused by the thin layer of weld slag formed on the weld surface.

[0006] Based on this, it is desirable to provide a gas-shielded solid welding wire that can improve the stability of the all-position welding arc from the perspective of welding slag. Summary of the Invention

[0007] One of the objectives of this invention is to provide a solid welding wire rod for gas-shielded all-position welding with self-slag removal. By considering the chemical elements that are highly correlated with the characteristics of the surface slag of the weld bead, the chemical composition system of the solid welding wire is designed in reverse. Within a certain range of welding process parameters, it can achieve uniform dispersion and spreading of the surface slag of the weld bead to both sides of the weld during the welding process and self-slag removal after welding. This avoids the problem of a large amount of slag accumulating in the center of the weld, which would deteriorate the conductivity and cause instability of the welding arc. This ensures the quality of all-position welding, which is very sensitive to the stability of the welding arc.

[0008] To achieve the above objectives, the present invention provides a solid welding wire rod for slag self-peeling all-position welding gas shielded welding, which contains Fe and unavoidable impurity elements, and further contains the following chemical elements in the following mass percentages:

[0009] C: 0.05~0.12%; Si: 0.7~1.4%; Mn: 1.0~1.9%; S: 0.008~0.02%; Ti: 0.08~0.19%; Al: 0.01~ 0.08%; Zr: 0.01~0.06%; Ni: 0.1~0.8%; Mo: 0.09~0.25%; Y: 0.02~0.07%; O: 0.003~0.008%.

[0010] This invention also provides a solid welding wire rod for gas-shielded slag self-peeling all-position welding, wherein the mass percentage content of each chemical element is as follows:

[0011] C: 0.05–0.12%; Si: 0.7–1.4%; Mn: 1.0–1.9%; S: 0.008–0.02%; Ti: 0.08–0.19%; Al: 0.01–0.08%; Zr: 0.01–0.06%; Ni: 0.1–0.8%; Mo: 0.09–0.25%; Y: 0.02–0.07%; O: 0.003–0.008%; balance Fe and unavoidable impurities.

[0012] Furthermore, the mass percentage content of each chemical element in the slag self-peeling all-position welding gas-shielded solid welding wire rod of the present invention further satisfies at least one of the following:

[0013] C: 0.06–0.1%;

[0014] Si: 1.1–1.4%;

[0015] Mn: 1.3–1.7%;

[0016] S: 0.009~0.017%;

[0017] Ti: 0.1–0.17%;

[0018] Al: 0.03–0.05%;

[0019] Zr: 0.03~0.05%;

[0020] Ni: 0.3–0.7%;

[0021] Mo: 0.12–0.2%;

[0022] Y: 0.04~0.06%;

[0023] O: 0.004~0.006%.

[0024] The gas-shielded solid welding wire rod of this invention addresses the mechanism by which a thin layer of slag accumulates on the surface of the weld bead during multi-layer, multi-pass welding, isolating the welding arc from the weld metal and reducing conductivity, thereby deteriorating the welding arc stability and all-position welding quality. By controlling the range of chemical elements highly correlated with the characteristics of the surface slag, the chemical composition system of the solid welding wire is designed in reverse. Within a certain range of welding process parameters, this allows for the uniform dispersion and spreading of the surface slag to both sides of the weld during welding, as well as self-peeling after welding. This avoids the problem of a large amount of slag accumulating in the center of the weld, which deteriorates conductivity and causes welding arc instability. This ensures the all-position welding quality, which is highly sensitive to welding arc stability, thus guaranteeing the welding quality in complex spatial positions. This overcomes the limitations of existing technologies that focus more on the addition of alloying elements to the welding wire to ensure the service performance of the welded joint.

[0025] Specifically, the design principles of each chemical element in this invention are as follows:

[0026] C: Carbon is an inherent strengthening element in ferroalloys and is crucial for material strength. In this invention, carbon, as a significant austenite expander, contributes to the formation of more low-temperature phase transformation structures during the solidification phase transformation of the weld metal, preventing the formation of bulk proeutectoid ferrite at high temperatures and contributing to the weld metal's toughness. However, for the composition system of this invention, excessive carbon content reacts with oxygen during the molten pool reaction stage, increasing welding spatter, reducing arc stability, and causing hardening and embrittlement of the weld metal. Therefore, this invention controls the C content to 0.05–0.12%.

[0027] Si: Silicon is a crucial deoxidizer, ensuring the purity of the weld metal. During the molten pool reaction stage, silicon primarily forms oxides that float on the surface of the liquid molten pool. The addition of silicon improves the surface tension of the molten pool, enhancing the fluidity of the weld metal and slag, which is beneficial for their uniform dispersion and spreading. Furthermore, in this invention, the difference in thermal expansion coefficients between silicon oxides and the weld metal is significant, and both exist in an incoherent form, resulting in higher brittleness. The slag easily peels off during post-weld cooling, without adversely affecting arc stability or welding quality. However, silicon is a strong ferrite-forming element; increased content can promote the formation of high-temperature phase transformation structures, which is detrimental to ensuring the toughness of the weld metal. Therefore, this invention controls the Si content to be 0.7–1.4%.

[0028] Mn: Manganese is an important solid solution strengthening element in carbon steel and low alloy steel welds, significantly improving strength after dissolving in ferrite. Simultaneously, manganese can significantly expand the austenite region; increasing the manganese content within a certain range helps delay the solid-state phase transformation to a lower temperature range, ensuring weld metal toughness. Furthermore, in this invention, from the perspective of slag formation, manganese is an important oxide and sulfide generating element. Manganese oxide is relatively tightly bound to the base metal, making it difficult to disperse, spread, and freely detach, which is detrimental to the slag's self-peeling properties. However, manganese sulfide exhibits better dispersion, spreading, and self-peeling properties. When coexisting with appropriate amounts of silicon oxide and other elements that promote slag embrittlement and peeling, the slag dispersion and self-peeling properties can still meet the requirements. Based on this, this invention controls Mn content to be 1.0–1.9%.

[0029] S: Sulfur is often controlled as a harmful element during normal flat or horizontal welding to avoid hot cracking defects and embrittlement of the weld metal. However, in this invention, the sulfides formed by sulfur with manganese and zirconium can reduce the adverse effects of manganese oxide on slag dispersion and embrittlement. Furthermore, sulfur itself significantly reduces the viscosity of the molten pool and surface slag, improving fluidity and positively impacting slag dispersion and self-peeling properties. Simultaneously, the hot cracking tendency of the weld metal can be controlled as long as sulfur and manganese are appropriately matched. Therefore, this invention adds and controls sulfur as a beneficial element, maintaining its content at 0.008–0.02%.

[0030] Ti: The dispersed distribution of nitrides and oxides generated by titanium during the molten pool reaction stage promotes heterogeneous nucleation within columnar grains, refining the grain size and improving the strength and toughness of the weld metal. Furthermore, as a chemical element with strong affinity for oxygen, carbon, and nitrogen, titanium plays a role in deoxidation, carbon fixation, and nitrogen fixation during the molten pool reaction stage, improving the purity of the weld metal and ensuring the overall performance of the weld joint. Moreover, in this invention, titanium oxide existing in the form of surface weld slag has a certain degree of dispersion and spreading, and its difference in thermal expansion properties with the ferrite matrix makes it easy to remove after welding. Simultaneously, titanium has a relatively low ionization potential, making it an element that can be directly added in welding metallurgy with a significant arc-stabilizing effect, directly impacting the stability of the welding arc. Based on this, this invention controls Ti content to be 0.08%–0.19%.

[0031] Al: Aluminum plays a significant role in deoxidation and nitrogen fixation in low-alloy steel welding wire, especially in vacuum smelting, where its deoxidation efficiency is higher than that of commonly used silicon, manganese, and calcium. To limit the oxygen content in the weld metal and thus reduce the total amount of slag generated during multi-layer, multi-pass welding, a certain amount of aluminum needs to be added. However, in this invention, the alumina slag generated during the molten pool reaction stage has a high viscosity and exhibits a certain directional coherent relationship with the ferrite matrix. This not only easily accumulates in the weld center but is also relatively difficult to remove, affecting the stability of the welding arc. Therefore, to ensure slag dispersion and self-peeling characteristics, this invention controls the Al content to 0.01–0.08%.

[0032] Zirconium (Zr) is not only an important carbide-forming element, playing a role in carbon fixation and promoting heterogeneous nucleation and grain refinement during solid-state phase transformation, but in this invention, Zr is also a high-melting-point, stable sulfide-forming element. When combined with manganese, it can prevent welding hot cracking in situations with high sulfur content, and it improves slag fluidity and promotes slag dispersion and self-peeling in multi-layer, multi-pass welding. Based on this, the Zr content is controlled at 0.01–0.06% in this invention.

[0033] Ni (Ni): After infinite solid solution formation with iron, nickel significantly improves the toughness of the metal. Simultaneously, nickel significantly expands the austenite region, which is beneficial for low-temperature solid-state phase transformation, improving the weld metal properties from a microstructural perspective. The addition of nickel plays a positive role in ensuring the service performance of the joint. However, in this invention, nickel significantly increases the viscosity of the liquid weld slag, reducing the slag's spreading effect towards the weld edge during multi-layer, multi-pass welding. It also increases the bonding force between the slag and the ferrite matrix, decreasing the slag's dispersion, spreading ability, and self-peeling properties. Therefore, this invention controls the Ni content to 0.1%–0.8%.

[0034] Mo (Mo): Molybdenum is an alloying element that contributes to both strength and toughness. It significantly improves strength during the solid-state phase transformation of weld metal during cooling. Its role in delaying the austenite transformation temperature and expanding the low-temperature phase transformation temperature range also promotes the formation of a fine-grained, high-toughness low-temperature phase transformation microstructure, ensuring the toughness of the weld metal. Therefore, it is a crucial element for regulating the overall mechanical properties of welded joints. However, in this invention, molybdenum also hardens the oxidizing slag on the weld bead surface and increases its bonding force with the ferrite matrix, reducing the self-peeling characteristics of the slag after welding. Therefore, the adverse effect of molybdenum on slag peeling needs to be balanced by adding other elements. Based on this, the Mo content in this invention is controlled at 0.09–0.25%.

[0035] Yttrium (Y): Yttrium is a heavy rare earth element that exhibits high activity during the molten pool reaction. It can react with most non-metallic impurities to purify the weld metal and improve its overall mechanical properties. In this invention, the slag containing yttrium has low viscosity and good dispersion and spreading properties. After solidification, the slag has a high coefficient of linear expansion, thus ensuring its dispersion, spreading, and self-peeling. Furthermore, after yttrium activates the molten pool and slag system, it reduces the bonding force of some slag elements that easily form coherent relationships with the ferrite matrix, which also facilitates slag peeling after welding. Based on this, the Y content is controlled at 0.02% to 0.07% in this invention.

[0036] O: In this invention, increased oxygen content is the main factor in slag formation. Although increased oxygen content can improve slag fluidity and thus its dispersion and spreading ability, a balance needs to be struck between controlling the total amount of slag and ensuring dispersion, spreading, and self-peeling. Meanwhile, a large amount of residual oxide inclusions inside the weld can lead to embrittlement. Therefore, this invention controls O: to be 0.003–0.008%.

[0037] Furthermore, the mass percentage of unavoidable impurity elements in the slag self-peeling all-position welding gas-shielded solid welding wire rod of the present invention satisfies the following conditions: P≤0.01%, N≤0.008%.

[0038] The unavoidable impurities in this invention are mainly P and N.

[0039] Phosphorus is generally restricted as a harmful element in carbon steel and low-alloy steel, mainly because it can form brittle compounds with iron and cause severe segregation, leading to significant embrittlement of the weld metal. Although phosphorus has positive effects in improving the surface tension of the molten pool and slag and increasing fluidity, it is still restricted as a harmful element when considering that the combination of other elements already meets the requirements.

[0040] Nitrogen is an impurity element in welding wire and should be kept at a low level as much as possible. Excessive nitrogen content can lead to the formation of nitride aggregates with related alloying elements, and excessive nitrogen dissolved in ferrite can also cause severe embrittlement of the weld.

[0041] Furthermore, in the slag self-peeling all-position welding gas-shielded solid welding wire rod described in this invention, it also satisfies at least one of the following:

[0042] Slag precipitation parameter S sp The control range is 4.8–6.9;

[0043] Slag embrittlement parameter S br The value should be controlled above 1.5; among which:

[0044] S sp =150[O]+55[S]+0.3[Mn]+0.6[Si]+4[Ti]+18[Al]+12[Zr]+21[Y],

[0045]

[0046] In the formula, each chemical element is replaced with the value before the percentage sign of its mass percentage content.

[0047] In multi-layer, multi-pass gas metal arc welding, the thin layer of slag on the weld surface is mainly composed of oxides, sulfides, and a small amount of nitrides formed by alloying elements. The slag spreads to both sides of the weld during solidification and has self-peeling characteristics after solidification, depending on its melting point, viscosity, surface tension, coefficient of linear expansion, and crystallographic bonding with the base metal. Different chemical elements have different effects on the characteristics of surface slag.

[0048] This invention fits a chemical element that is highly correlated with the total amount of welding slag formation and the ease of slag self-peeling as a slag precipitation parameter S. sp and slag embrittlement parameter S br By designing the reverse chemical composition, the precipitation parameter S of the slag was controlled. sp Based on this, appropriately increase the embrittlement parameter S of the slag. br This allows for the uniform dispersion and spreading of molten slag on the surface of the weld bead to both sides of the weld during multi-layer, multi-pass welding, as well as self-peeling after welding, ensuring the stability of the welding arc in all positions and the final welding quality.

[0049] Within the chemical composition range of this invention, the slag precipitation parameter S sp The embrittlement parameter S of the slag should be controlled between 4.8 and 6.9. br The value is controlled above 1.5 because: if the slag precipitation parameter S... sp If the slag concentration is too low, the amount of slag generated on the surface of multi-layer, multi-pass welds will be very small, which is certainly beneficial to arc stability. However, according to the basic principles of weld pool metallurgy, the oxygen content remaining in the weld will increase, which is very detrimental to the overall mechanical properties of the weld. If the slag precipitation parameter S... spIf the slag concentration is too high, excessive slag formation will increase the risk of slag inclusions in the weld, even if the weld exhibits the characteristics of spreading and self-peeling. If the slag embrittlement parameter S... br If the value is too small, the bonding force between the slag and the base metal will be enhanced, the coefficient of thermal expansion will be reduced, which is not conducive to achieving slag self-peeling.

[0050] Furthermore, in the slag self-peeling all-position welding gas-shielded solid welding wire rod of the present invention, the microstructure of its deposited metal is a low-temperature phase transformation structure dominated by bainite, and the total volume content of the bulk proeutectoid ferrite and side strip ferrite formed during the high-temperature phase transformation process is less than 5%.

[0051] Furthermore, in the slag self-peeling all-position welding gas-shielded solid welding wire rod described in this invention, the properties of the deposited metal meet the following requirements: tensile strength ≥625MPa, yield strength ≥550MPa, and low-temperature impact energy KV2 ≥70J at -10℃.

[0052] Another object of the present invention is to provide a slag-self-peeling all-position welding gas-shielded solid welding wire, which is made from the gas-shielded solid welding wire rod as described above.

[0053] In the preparation process, the wire rod is first smelted, refined, cast, hot rolled, and annealed in a vacuum electric furnace to obtain the wire rod. Then, the finished welding wire is prepared by drawing and winding the welding wire.

[0054] Furthermore, the surface of the gas-shielded solid welding wire of the present invention has a copper plating layer.

[0055] The present invention can also improve the welding arc stability by increasing the conductivity and wire feeding stability of the welding wire by plating copper on the surface of the welding wire.

[0056] During preparation, copper plating is performed after the wire drawing step.

[0057] Since the preparation process of the wire rod and welding wire in this case is not an improvement over the prior art, that is, conventional processes in the field can be used, the preparation process of the wire rod and welding wire will not be described in detail in this invention.

[0058] The slag-self-peeling all-position welding gas-shielded solid welding wire rod and welding wire described in this invention have the following beneficial effects:

[0059] This invention breaks through conventional design thinking. Considering the actual situation that welding quality in complex spatial positions is very sensitive to arc stability, it extracts the slag precipitation parameter S. sp and slag embrittlement parameter S br By reverse-engineering the chemical composition of the welding wire, controlling the total amount of multi-layer and multi-pass welding slag, and improving its dispersion, spreading, and self-peeling capabilities, the conductivity uniformity is improved and the welding arc is stably burned, thereby ensuring welding quality.

[0060] The gas-shielded solid welding wire of this invention has a moderate strength level, good toughness, tensile strength ≥625MPa, yield strength ≥550MPa, and low-temperature impact energy KV2 ≥70J at -10℃. Therefore, it has a wide range of applications and solves the problem of welding material matching in many industrial fields with requirements for uniform welding quality in spatial positions.

[0061] This invention employs a commonly used combination of chemical elements, fully leveraging the close correlation between elements during the molten pool reaction process, achieving the most ideal performance indicators at the lowest cost, and combining economy and applicability. Detailed Implementation

[0062] The following will provide a further explanation and description of the slag self-peeling all-position welding gas-shielded solid welding wire rod and welding wire of the present invention with reference to specific embodiments. However, this explanation and description do not constitute an improper limitation on the technical solution of the present invention.

[0063] Examples 1-6

[0064] Table 1 lists the mass percentage of each chemical element in the slag self-peeling all-position welding gas-shielded solid welding wire rods and welding wires of Examples 1-6.

[0065] Table 1. (wt%, balance Fe and other unavoidable impurities besides P and N)

[0066]

[0067] The slag-self-peeling all-position welding gas-shielded solid welding wires described in Examples 1-6 of this invention are all prepared using the following steps:

[0068] The ingots are smelted, refined, and cast in a vacuum electric furnace to obtain ingots with the chemical composition shown in Table 1. Then, the wire rods are hot rolled, annealed, drawn, copper-plated, wound, and packaged to finally obtain finished welding wire with a diameter of 1.0 mm.

[0069] This invention conducts performance tests on gas-shielded solid welding wires for all-position welding of pipelines using the slag-self-peeling method described in Examples 1-6. The arc stability during welding and the final all-position weld formation quality are evaluated. The gas-shielded solid welding wires of Examples 1-6 are comprehensively evaluated based on four indicators: appropriate slag total amount, slag dispersion and spreading, slag self-peeling property, and arc stability. The evaluation results are listed in Table 2. In the pipeline all-position welding performance evaluation test, since the edge characteristics of multi-layer, multi-pass filler welds are difficult to observe, only the quality of the capping weld is evaluated. The capping welding current is 200-230A, the welding voltage is 22-24V, and the welding speed is 320-380mm / min. Appropriate welding torch oscillation is performed according to the bevel width before capping welding to ensure the bevel edge coverage of the single-pass capping weld.

[0070] The performance evaluation results of the all-position welding process of gas-shielded solid welding wire for slag self-peeling welding in Examples 1 to 6 are shown in Table 2.

[0071] Table 2.

[0072] Example Moderate total slag content Slag Dispersion and Spreadability Slag self-stripping properties Arc stability 1 ● ● ○ ● 2 ○ ○ ○ ○ 3 ○ ● ● ● 4 ○ ○ ○ ○ 5 ○ ○ ○ ○ 6 × ○ ○ ○

[0073] Note: In Table 2, ○ indicates excellent, ● indicates good, and × indicates poor. Excellent arc stability means welding current fluctuations are less than 3% and welding voltage fluctuations are less than 2%; good arc stability means welding current fluctuations are 3%–6% and welding voltage fluctuations are 2%–5%; poor arc stability means welding current fluctuations are greater than 6% and welding voltage fluctuations are greater than 5%. For slag total weight moderation, "excellent" means the total slag coverage of a randomly selected 300mm weld bead is less than 20%; "good" means the total slag coverage of a randomly selected 300mm weld bead is between 20% and 50%; and "poor" means the total slag coverage of a randomly selected 300mm weld bead exceeds 50%. Slag dispersion and spreadability are measured by the amount of slag remaining at the centerline of a randomly selected 300mm weld bead. "Excellent" means less than 10% slag remaining at the centerline; "Good" means between 10% and 30%; and "Poor" means more than 30%. For slag self-removal properties, "Excellent" means the slag will peel off spontaneously upon cooling and can be completely removed with a manual wire brush in one pass; "Good" means more than 75% will be removed with a manual wire brush in one pass; and "Poor" means less than 75% will be removed with a manual wire brush in one pass.

[0074] It can be seen that the slag dispersion and spreading properties, slag self-peeling properties, and arc stability of Examples 1 to 6 are all excellent, while those of Example 6 are inferior.sp The value is not within the range controlled by the preferred embodiment of the present invention, therefore the total amount of slag is too small, and the oxygen content of the weld metal is at risk of exceeding the standard.

[0075] Furthermore, as can be seen from Table 2, Examples 2, 4, and 5 exhibit better all-position welding adaptability compared to Examples 1, 3, and 6.

[0076] The inventors also conducted welding tests on the slag-self-peeling all-position welding gas-shielded solid welding wires of Examples 1-6 according to the requirements of GB / T8110-2008 standard, and evaluated the strength and impact toughness of the weld metal to assess its mechanical adaptability during service. Table 3 lists the mechanical properties of the weld metal obtained by welding the slag-self-peeling all-position welding gas-shielded solid welding wires of Examples 1-6. During the solid welding wire weld metal welding tests, the welding current was 230-250A, the welding voltage was 24-26V, and the welding speed was 340mm / min.

[0077] Table 3.

[0078] Example Yield strength (MPa) Tensile strength (MPa) Impact toughness (KV2, -10℃) 1 568 644 83 2 564 645 74 3 574 665 163 4 582 666 163 5 590 674 107 6 598 682 77

[0079] As can be seen from Table 3, the gas-shielded solid welding wires of Examples 1 to 6 of the present invention all meet the following mechanical properties of the deposited metal: tensile strength > 625 MPa, yield strength > 550 MPa, and low-temperature impact energy (KV) > 70 J at -10℃. From the perspective of the mechanical properties of the deposited metal of the solid welding wires, Examples 3 and 4 exhibit superior mechanical properties.

[0080] It should be noted that the combination of the technical features in this case is not limited to the combination methods described in the claims of this case or the combination methods described in the specific embodiments. All technical features described in this case can be freely combined or combined in any way, unless they contradict each other.

[0081] It should also be noted that the embodiments listed above are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and similar changes or modifications made thereto are those that can be directly derived or easily conceived by those skilled in the art from the content disclosed in the present invention, and should all fall within the protection scope of the present invention.

Claims

1. A solid welding wire rod for gas-shielded all-position welding with slag self-peeling, characterized in that, Its mass percentage content of each chemical element is as follows: C: 0.05~0.12%; Si: 0.7~1.4%; Mn: 1.0~1.9%; S：0.008~0.02% ； Ti: 0.08~0.19%; Al: 0.01~0.08%; Zr: 0.01~0.06%; Ni: 0.1~0.8%; Mo: 0.09~0.25%; Y: 0.02~0.07%; O: 0.003~0.008%; balance is Fe and unavoidable impurities; It also satisfies at least one of the following conditions: Slag precipitation parameter S sp The control range is 4.8~6.9; Slag embrittlement parameter S br Keep it above 1.5; in: ， In the formula, each chemical element is replaced with the value before the percentage sign of its mass percentage content.

2. The slag-self-peeling all-position welding gas-shielded solid welding wire rod as described in claim 1, characterized in that, Its mass percentage content of each chemical element further satisfies at least one of the following conditions: C：0.06~0.1%； Si: 1.1~1.4%; Mn: 1.3~1.7%; S：0.009~0.017% ； Ti: 0.1~0.17%; Al：0.03~0.05%； Zr：0.03~0.05%； Ni: 0.3~0.7%; Mo: 0.12~0.2%; Y：0.04~0.06%； O：0.004~0.006%。 3. The slag-self-peeling all-position welding gas-shielded solid welding wire rod as described in claim 1, characterized in that, The unavoidable impurity element mass percentage content meets the following requirements: P≤0.01%, N≤0.008%.

4. The slag-self-peeling all-position welding gas-shielded solid welding wire rod as described in claim 1, characterized in that, The microstructure of the deposited metal includes a low-temperature phase transformation structure dominated by bainite, in which the total volume content of the bulk proeutectoid ferrite and side strip ferrite formed during the high-temperature phase transformation process is less than 5%.

5. The slag-self-peeling all-position welding gas-shielded solid welding wire rod as described in claim 1, characterized in that, Its deposited metal properties meet the following requirements: tensile strength ≥625MPa, yield strength ≥550MPa, and low-temperature impact energy KV2 ≥70J at -10℃.

6. A slag-self-peeling gas-shielded solid welding wire for all-position welding, characterized in that, It is made from gas-shielded solid welding wire rod as described in any one of claims 1-5.

7. The gas-shielded solid welding wire as described in claim 6, characterized in that, Its surface has a copper plating layer.

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