Low spatter rate gas shielded solid wire electrode for all position automatic welding and welding wire

Abstract

The application discloses a low-splatter gas-protected solid wire rod for full-position automatic welding, which contains Fe and inevitable impurities, and also contains the following chemical elements with mass percentage as follows: C: 0.03-0.07%; Si: 0.25-0.55%; Mn: 0.75-1.25%; 0 The application also discloses a low-splatter gas-protected solid wire for full-position automatic welding, which is prepared by using the above gas-protected solid wire rod. The application further discloses a full-position automatic welding process, which is implemented by using the above gas-protected solid wire.

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 currently the most widely used welding method in industry. It has the advantages of convenient operation, high welding efficiency, low overall cost, and good reproducibility of welding quality. By matching appropriate welding process specifications to different industrial application requirements, it can meet the requirements of welding quality and joint performance of structural components in various application scenarios, and provide an important guarantee for the integrity of welded structures and service safety.

[0003] However, the welding of many large structural components often involves complex spatial welding positions, 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 non-flat and horizontal welding positions, the welding quality is very sensitive to the stability of the weld droplet transfer. Welding spatter often causes instability in the welding process and leads to welding defects.

[0004] In applications involving deep groove and narrow gap welding, welding spatter often causes poor fusion defects on both sides of the narrow gap groove. For steel structure welding under dynamic loads, large spatter particles in the stress concentration areas on both sides of the weld can become initial fatigue crack initiation sites, reducing the fatigue service life of the welded structure. Therefore, the spatter characteristics of gas-shielded solid welding wire during the droplet transfer process are crucial to the stability of the entire welding process and weld quality. Optimizing the chemical composition of solid welding wire to achieve low spatter rates and welding process stability can provide an effective solution for engineering applications.

[0005] In the prior art, existing patent literature involves gas-shielded solid welding wire, for example:

[0006] Chinese patent document CN101249593A, published on August 27, 2008, entitled "Gas Shielded Welding Solid Wire for X80 Pipeline Steel", discloses a gas shielded welding solid wire for X80 pipeline steel. It achieves the highest strength matching of X80 pipeline steel pipe through the combination and configuration of basic chemical elements, and has high toughness and certain corrosion resistance. However, it does not make special designs for the spatter characteristics during the welding process, nor does it describe the stability of arc combustion and droplet transfer.

[0007] Chinese patent document CN1970212A, published on October 24, 2006, entitled "Solid Welding Wire for Gas Shielded Arc Welding," discloses a solid welding wire for gas shielded arc welding. By controlling the yield strength ratio and hardening factor of the welding wire during the wire processing and drawing process, the deformation characteristics and straightness of the welding wire in the hose are controlled, ensuring the stability of wire feeding and welding quality. However, it does not describe controlling welding spatter and improving the stability of droplet transfer through directional design during the welding process, thereby ensuring the stability of welding quality.

[0008] Chinese patent document CN1868657A, published on May 22, 2006, entitled "Copper-plated Solid Welding Wire with Excellent Arc Stability," discloses a copper-plated solid welding wire with excellent arc stability. This is achieved by adding inorganic additives, primarily alkali metal and alkaline earth metal salts, to the plating solution during the copper plating process. This improves the electroplating adhesion of the welding wire and forms a composite coating containing alkali metal and alkaline earth metal ions on the wire surface. This fully utilizes the low ionization energy of alkali metals and alkaline earth metals to enhance stability during arc combustion and transfer. However, while this method effectively utilizes the advantages of low-ionization-potential chemical elements in improving arc and droplet transfer stability, it places high demands on the uniformity of the coating and the surface roughness of the welding wire. If uneven coating or peeling occurs, its design advantages cannot be realized. Summary of the Invention

[0009] One of the objectives of this invention is to provide a low-spatter gas-shielded solid welding wire rod for all-position automatic welding, which achieves low spatter and good weld formation during the welding process, resulting in a welded joint with good comprehensive mechanical properties.

[0010] To achieve the above objectives, the present invention provides a low-spatter gas-shielded solid welding wire rod for all-position automated welding, which contains Fe and unavoidable impurities, and further contains the following chemical elements in the following mass percentages:

[0011] C: 0.03~0.07%; Si: 0.25~0.55%; Mn: 0.75~1.25%; 0<S≤0.007%; 0<P≤0.009%; Ti: 0.04~0.12%; Al: 0.02~0.08 %; Ca: 0.009~0.05%; Mg: 0.008~0.035%; Cr: 0.04~0.09%; Ce: 0.06~0.25%; Y: 0.05~0.20%; O: 0.0085~0.015%.

[0012] Furthermore, in the gas-shielded solid welding wire rod described in this invention, the mass percentage content of each chemical element is as follows:

[0013] C: 0.03–0.07%; Si: 0.25–0.55%; Mn: 0.75–1.25%; 0 < S ≤ 0.007%; 0 < P ≤ 0.009%; Ti: 0.04–0.12%; Al: 0.02–0.08%; Ca: 0.009–0.05%; Mg: 0.008–0.035%; Cr: 0.04–0.09%; Ce: 0.06–0.25%; Y: 0.05–0.20%; O: 0.0085–0.015%; balance Fe and unavoidable impurities.

[0014] In this invention, the lower silicon, manganese, and titanium chemical composition effectively ensures the oxidizing properties of the molten droplets during the arc generation stage. Thermodynamically, this avoids a high proportion of endothermic reactions in the shielding gas, preventing the generation of large amounts of CO and thus reducing the likelihood of arc temperature drop and droplet bursting, which could lead to spatter. The low carbon content also ensures the stability of the CO2 atmosphere. The combined addition of low-ionization-potential chemical elements Mg and Ca enhances the electron emission capability of the arc space during the droplet stage, helping to expand the arc column space, increase the area of ​​the arc root cathode spot, further reduce or eliminate the disordered arc contraction effect caused by the endothermic conversion of CO2 gas to CO, improve the stability of arc combustion and welding process, and reduce welding spatter. The role of rare earth element composite alloying is mainly reflected in the molten pool reaction and the solid-state phase transformation stage of the weld metal after solidification. It aims to improve the oxide morphology and distribution in the weld metal lacking deoxidizers and eliminate the adverse effects of excessive oxide content on the overall performance of the weld metal.

[0015] Specifically, the design principles of each chemical element in the low-spatter-rate gas-shielded solid welding wire rod for all-position automatic welding described in this invention are as follows:

[0016] C: In the gas-shielded solid welding wire rod described in this invention, carbon is an inherent and important non-metallic element in steel materials, largely determining the metallurgical characteristics of the molten pool and the solid-state phase transformation characteristics of the weld metal. It is also the chemical element that contributes the most to the strength of carbon steel and low-alloy high-strength steel. Simultaneously, carbon has a significant effect on expanding the austenite region, helping to delay the solid-state phase transformation to a low temperature during post-weld cooling, forming a low-temperature phase transformation structure with good toughness, which makes a significant contribution to the toughness of the weld metal. However, in CO2-rich argon mixed gas shielded welding, excessively high carbon content can easily undergo an endothermic reaction with CO2 during the droplet stage, generating a large amount of CO, while simultaneously lowering the arc temperature, causing the arc column and cathode spot to shrink, thus leading to welding spatter. Therefore, in the gas-shielded solid welding wire rod described in this invention, the mass percentage of carbon is controlled between 0.03% and 0.07%.

[0017] Si: In the gas-shielded solid welding wire rod described in this invention, silicon is generally used as an important deoxidizer to ensure the purity of the weld metal. Simultaneously, silicon can significantly reduce the surface tension of the weld droplets and, within a certain composition range, refines the droplet transition, thus contributing to the stability of the welding process. However, if the silicon content is too high, the surface tension of the droplets will decrease drastically, making it difficult to form a stable droplet-like jet transition. Even under high-current welding conditions, unstable short-circuit transitions will occur, which is detrimental to the stability of the welding arc and the entire welding process. Therefore, in the gas-shielded solid welding wire rod described in this invention, the mass percentage of Si is controlled between 0.25% and 0.55%.

[0018] Mn: In the gas-shielded solid welding wire rod of the present invention, manganese is an important deoxidizing and solid solution strengthening element in carbon steel and low-alloy high-strength steel welds. Its contribution to weld strength is second only to carbon, and its deoxidizing effect is second only to silicon. Simultaneously, manganese also significantly expands the austenite region; increasing the manganese content within a certain range is beneficial for low-temperature solid-state phase transformation and can improve weld metal toughness while ensuring weld metal strength. However, excessive silicon content can easily lead to welding spatter. Furthermore, if the manganese content is too high, the strong solid solution strengthening effect will lead to a decrease in weld metal ductility and toughness. Moreover, manganese has a high ionization potential, reducing the electron emission capability in the arc region, which is detrimental to the stability of the welding arc. Therefore, in the gas-shielded solid welding wire rod of the present invention, the mass percentage of Mn is controlled between 0.75% and 1.25%.

[0019] S: In the gas-shielded solid welding wire rod of the present invention, sulfur can significantly improve the surface tension of the liquid droplets at the tip of the welding wire, and under certain conditions, it has a significant effect on refining the droplets. Whether in the low or high welding current range, the refined droplets can significantly improve the stability of the welding arc. However, excessively high sulfur content not only causes severe hot cracking in the weld metal, but also makes it difficult to form a stable droplet-shaped transition in the arc region, resulting in unstable short-circuit transition, which is detrimental to the stability of the welding arc and the welding process. Therefore, in the gas-shielded solid welding wire rod of the present invention, the sulfur content is controlled to 0 < S ≤ 0.007%.

[0020] P: In the gas-shielded solid welding wire rod described in this invention, phosphorus can significantly improve the surface tension of the molten droplets at the wire tip under certain conditions, which helps to form finer droplets, thereby achieving a relatively stable droplet transfer over a wider welding current range and improving the welding arc stability. However, phosphorus can also form brittle compounds with iron and cause severe segregation, leading to significant embrittlement of the weld metal and increasing its tendency to cold crack. Therefore, in the gas-shielded solid welding wire rod described in this invention, the mass percentage of phosphorus is controlled to be 0 < P ≤ 0.009%.

[0021] Ti: In the gas-shielded solid welding wire rod described in this invention, titanium plays multiple beneficial roles in low-alloy steel welding wire. Firstly, titanium itself, as a low-ionization potential element, enhances the electron emission capability of the arc region and improves the stability of the welding arc. Furthermore, it has a higher yield than the three highly reactive metals magnesium, calcium, and aluminum, making it easier to add from the perspective of smelting process stability. Secondly, 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. Considering the high-oxidizing design of this welding wire product to avoid spatter during the arc droplet stage, the titanium content must be moderate. This ensures that while leveraging its low-ionization potential to stabilize the arc, excessive deoxidation can lead to excessive spatter during the droplet stage. Therefore, in the gas-shielded solid welding wire rod described in this invention, the mass percentage of Ti is controlled between 0.04% and 0.12%.

[0022] Al: In the gas-shielded solid welding wire rod described in this invention, aluminum plays a significant role in deoxidation and nitrogen fixation in low-alloy steel welding wire, exhibiting high deoxidation efficiency. Furthermore, aluminum itself is a low-ionization-potential chemical element, which, during the droplet stage, enhances electron emission capability and expands the arc column and cathode spot regions, thus contributing to arc stability and reducing spatter. However, the alumina slag generated during the molten pool reaction stage has a high viscosity and exhibits a unidirectional coherent relationship with the ferrite matrix, making it prone to accumulating in the weld center and relatively difficult to remove, thus affecting the welding arc stability. From the perspective of the microstructure evolution of the solid-state phase transformation in weld metal, aluminum is a typical ferrite-forming element, reducing austenite stability and promoting the formation of high-temperature phase transformation structures such as bulk ferrite and side-plate ferrite, which is detrimental to the overall performance of the weld metal. Therefore, in the gas-shielded solid welding wire rod described in this invention, the mass percentage of Al is controlled between 0.02% and 0.08%.

[0023] Ca and Mg: In the gas-shielded solid welding wire rod described in this invention, magnesium and calcium are both active alkaline earth metal elements. Their low ionization potential gives them a high electron emission capability in the welding arc region, which helps to expand the arc column space and increase the area of ​​the arc root cathode spot. This reduces or eliminates the disordered arc contraction effect caused by the endothermic conversion of CO2 gas to CO, effectively improving the stability of arc combustion and the welding process and reducing welding spatter. Simultaneously, magnesium and calcium also serve as additives in the refining process of welding wire steel, which helps ensure the purity of the welding wire steel. However, excessive addition of magnesium and calcium not only increases the amount of welding slag but also causes a decrease in the overall performance of the weld metal. Since magnesium and calcium are both very active metal elements, in order to ensure the yield in the final welding wire product, they need to be added after deoxidation and refining during the smelting process of the welding wire steel to avoid unnecessary burn-off during the smelting stage. Furthermore, adding them in the form of an aluminum-magnesium alloy can effectively ensure the magnesium yield. Therefore, in the gas-shielded solid welding wire rod of the present invention, the mass percentage content of Ca element is controlled between 0.009 and 0.05%, and the mass percentage content of Mg element is controlled between 0.008 and 0.035%.

[0024] Cr: In the gas-shielded solid welding wire rod of the present invention, chromium effectively ensures the strength index of the weld metal through post-weld cooling hardening. Simultaneously, under the condition of sufficient austenite-enlarging elements, an appropriate chromium content helps to suppress the growth of dendrites in the as-cast weld, reduce the overall grain size, promote the formation of low-temperature bainite, and improve the overall performance of the weld metal. Furthermore, chromium also has a moderate ionization potential and a certain electron emission capability, which has a positive effect on the stability of the welding arc and droplet transfer. Therefore, in the gas-shielded solid welding wire rod of the present invention, the mass percentage of Cr is controlled between 0.04% and 0.09%.

[0025] Ce and Y: In the gas-shielded solid welding wire rod of this invention, the light rare earth element cerium and the heavy rare earth element yttrium are important active metal elements added to this welding wire, and their beneficial effects are mainly reflected in the molten pool reaction stage. In order to achieve the stability of the welding arc combustion and droplet transfer stages and reduce welding spatter, the welding wire of this invention adopts a high oxidizing droplet environment design, which will result in a high oxide content in the weld pool and the solidified weld metal, which will have an adverse effect on the comprehensive mechanical properties of the weld metal. The combined addition of the two rare earth elements can effectively improve the morphology and distribution of a large number of oxides in the weld metal and eliminate the adverse effects of excessive oxide content on the comprehensive properties of the weld metal. Therefore, in the gas-shielded solid welding wire rod of this invention, the mass percentage of Ce element is controlled between 0.06% and 0.25%, and the mass percentage of Y element is controlled between 0.05% and 0.20%.

[0026] O: In the gas-shielded solid welding wire rod described in this invention, a specific high-oxidizing droplet environment design is adopted. By reducing the use of deoxidizers, a welding arc and droplet environment with higher oxygen content is formed, avoiding the effect of CO2 decomposition into CO explosion and endothermic arc column contraction in the argon-rich shielding gas mixture, thereby reducing the welding spatter rate. However, excessively high oxygen content will cause violent chemical reactions with metal elements and carbon during the droplet stage, not only resulting in a large amount of spatter and abnormal fluctuations in the welding arc, but also altering the final design and application effect of the welding wire due to excessive burning of beneficial chemical elements. Therefore, in the gas-shielded solid welding wire rod described in this invention, the mass percentage of oxygen is controlled between 0.0085% and 0.015%.

[0027] Furthermore, the mass percentage of unavoidable impurity elements in the gas-shielded solid welding wire rod described in this invention satisfies the following condition: N ≤ 0.007%.

[0028] The unavoidable impurity in this invention is mainly nitrogen (N), and its content should be as low as possible.

[0029] Excessive nitrogen content can lead to the formation of nitride aggregates with related alloying elements, and excessive nitrogen dissolved in ferrite can cause severe weld embrittlement. Therefore, in the gas-shielded solid welding wire rod described in this invention, the mass percentage of oxygen is controlled to N ≤ 0.007%.

[0030] Furthermore, the gas-shielded solid welding wire rod described in this invention also satisfies the following condition: welding spatter rate control coefficient SP ≤ 0.75%; wherein:

[0031]

[0032] Each chemical element in the formula is substituted with its mass percentage content.

[0033] In this invention, during gas metal arc welding (GMAW), the generation of welding spatter mainly originates from three aspects: First, the CO2 in the shielding gas undergoes high-temperature decomposition and absorbs heat, i.e., CO2 = CO + O2 - H. The CO gas explodes during its escape, directly causing spatter. Second, the endothermic reaction of CO2 decomposition at high temperature lowers the arc space temperature and causes the arc column and cathode spot to shrink, reducing the stability of arc combustion and causing spatter. Third, the disordered shrinkage caused by the decrease in arc space temperature increases the pressure of the cathode spot at the end of the arc, thereby increasing the resistance to droplet transfer and easily triggering non-axial droplet transfer, increasing spatter during the droplet transfer process. Considering both controlling the welding spatter rate and preventing excessive oxygen content that would reduce the overall performance of the weld metal, comprehensive optimization and design of chemical elements are carried out. Within the control range of relevant chemical elements, a series of combinations and adjustments are made to control the welding spatter rate control coefficient SP within 0.75.

[0034] Furthermore, the microstructure of the deposited metal in the gas-shielded solid welding wire rod of the present invention is a mixed structure, including small blocky ferrite, acicular ferrite and granular (small blocky) MA components.

[0035] Furthermore, the deposited metal properties of the gas-shielded solid welding wire rod described in this invention meet the following requirements: yield strength of 450-550 MPa, tensile strength of 560-600 MPa, and low-temperature impact energy KV2 ≥ 47 J at -10℃.

[0036] Another objective of this invention is to provide a low-spatter gas-shielded solid welding wire for all-position automatic welding. This gas-shielded solid welding wire is suitable for argon-rich mixed gas shielded welding in various application scenarios, including complex spatial welding of pipeline all-position automatic circumferential welds, deep bevel and narrow gap welding, and structural component welding under dynamic load fatigue service.

[0037] To achieve the above objectives, the present invention provides a low-spatter gas-shielded solid welding wire for all-position automatic welding, which is made from the aforementioned gas-shielded solid welding wire rod.

[0038] Furthermore, the spatter rate of the gas-shielded solid welding wire described in this invention is ≤8%.

[0039] Furthermore, the surface of the gas-shielded solid welding wire described in this invention has a copper plating layer.

[0040] Another objective of this invention is to provide an all-position automatic welding process that, combined with a certain range of welding process specifications, can guarantee the quality of all-position welding and meet the requirements for all-position welding of pipelines.

[0041] To achieve the above objectives, the present invention provides an all-position automatic welding process, which is implemented using the aforementioned gas-shielded solid welding wire.

[0042] Furthermore, in the all-position automatic welding process described in this invention, the welding current is controlled to be 180-220A, the welding voltage to be 19-24V, and the welding speed to be 300-450mm / min.

[0043] The low-spatter gas-shielded solid welding wire rod and welding wire for all-position automatic welding described in this invention have the following beneficial effects:

[0044] The present invention provides a multi-dimensional directional design scheme for the chemical composition of the low-spatter gas-shielded solid welding wire rod and welding wire for all-position automatic welding, which achieves low spatter and good weld formation during the welding process, resulting in a welded joint with good comprehensive mechanical properties.

[0045] The low-spatter gas-shielded solid welding wire rod and welding wire described in this invention for all-position automatic welding have a wide range of applications and broad prospects. They can be applied to welding situations in complex spatial positions, especially in all-position pipeline welding where welding spatter is highly sensitive, narrow-gap welding where edge fusion capability is required to be high, and situations where welded joints have dynamic load fatigue design requirements. With a significant reduction in welding spatter, the quality of all-position welding can remain stable, the rate of non-fusion defects at the edge of narrow-gap welds will be significantly reduced, and welded structural components used in dynamic load applications will also have improved fatigue service life due to the reduction of fatigue crack initiation sources caused by large-particle spatter.

[0046] The low-spatter gas-shielded solid welding wire rod and welding wire for all-position automatic welding described in this invention adopt commonly used chemical element combinations. Through highly correlated design, the stability of welding arc combustion and welding process is achieved, effectively reducing welding spatter, resulting in stable welding quality and weld metal with good comprehensive performance. It achieves the most ideal performance indicators at a lower cost, and is both economical and applicable.

[0047] In some embodiments, the low-spatter gas-shielded solid welding wire rod and the weld metal properties of the welding wire for all-position automatic welding described in this invention meet the following requirements: yield strength of 450-550 MPa, tensile strength of 560-600 MPa, low-temperature impact energy KV2≥47J at -10℃, and have low spatter rate, good welding process stability and weld formation quality, and good comprehensive mechanical properties. Detailed Implementation

[0048] The following will provide further explanation and description of the low-spatter-rate gas-shielded solid welding wire rod and welding wire for all-position automatic welding according to the present invention, with reference to specific embodiments. However, this explanation and description do not constitute an undue limitation on the technical solution of the present invention.

[0049] Examples 1-5

[0050] Tables 1-1 and 1-2 list the mass percentage of each chemical element in the low-spatter gas-shielded solid welding wire rods and the welding wire before copper plating for all-position automated welding in Examples 1-5.

[0051] Table 1-1. (wt%, balance Fe and other unavoidable impurities besides O and N)

[0052] Example C Si Mn S P Ti Al Ca 1 0.03 0.25 1.25 0.005 0.009 0.04 0.08 0.015 2 0.04 0.30 1.10 0.006 0.006 0.06 0.06 0.009 3 0.04 0.40 0.95 0.006 0.005 0.08 0.04 0.025 4 0.06 0.50 0.90 0.007 0.008 0.10 0.03 0.040 5 0.07 0.55 0.75 0.005 0.007 0.12 0.02 0.050

[0053] Table 1-2. (wt%, balance Fe and other unavoidable impurities besides O and N)

[0054] Example Mg Cr Ce Y O N SP 1 0.030 0.09 0.08 0.07 0.0095 0.005 0.74 2 0.035 0.07 0.06 0.05 0.0085 0.006 0.73 3 0.025 0.05 0.13 0.15 0.0105 0.004 0.69 4 0.016 0.05 0.20 0.18 0.0110 0.007 0.74 5 0.008 0.04 0.25 0.20 0.0150 0.005 0.75

[0055] Note: In the above table, In the formula, each chemical element is replaced with the value before the percentage sign of its mass percentage content.

[0056] The low-spatter gas-shielded solid welding wire rods and welding wires for all-position automatic welding described in Examples 1-5 of this invention are all prepared using the following steps:

[0057] 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.

[0058] All-position welding of pipelines was performed using the low-spatter gas-shielded solid welding wires for all-position automatic welding described in Examples 1-5. The welding current was controlled at 180–220 A, the welding voltage at 19–24 V, and the welding speed at 300–450 mm / min. Table 2 lists the welding process parameters for each example.

[0059] Table 2.

[0060]

[0061]

[0062] Samples were taken from the weld metal obtained by the above welding process in Examples 1-5, and their microstructure was observed and tested by a high-resolution metallographic microscope. The reference test standard was GB / T13298: Test Method for Metal Microstructure, which standardized the preparation, etching and microscopic photography of the samples. The microstructure observation results are listed in Table 3.

[0063] Table 3 lists the microstructure observation results of the low-spatter-rate gas-shielded solid welding wire rods for all-position automated welding in Examples 1-5.

[0064] Table 3.

[0065] Example Microorganism 1 Small blocky ferrite, acicular ferrite and granular (small blocky) MA components 2 Small blocky ferrite, acicular ferrite and granular (small blocky) MA components 3 Small blocky ferrite, acicular ferrite and granular (small blocky) MA components 4 Small blocky ferrite, acicular ferrite, and granular (small blocky) MA components 5 Small blocky ferrite, acicular ferrite and granular (small blocky) MA components

[0066] Based on the above welding process, performance tests were conducted on all-position welding of pipelines. The welding spatter characteristics, welding process stability, and comprehensive mechanical properties of the weld metal in each embodiment were comprehensively evaluated, and the evaluation results are listed in Table 4. Among them:

[0067] Weld spatter characteristics definition:

[0068] Excellent: The welding spatter rate based on GB / T 25776 (Method for Evaluation of Welding Process Performance of Welding Materials) does not exceed 5%;

[0069] Good: The welding spatter rate, based on GB / T 25776 (Method for Evaluation of Welding Process Performance of Welding Materials), does not exceed 8%.

[0070] Definition of welding process stability:

[0071] Excellent: Based on the constant current characteristic welding power supply, the unidirectional current fluctuation during the welding process does not exceed 3%;

[0072] Good: Based on the constant current characteristic welding power supply, the unidirectional fluctuation of current during welding does not exceed 5%.

[0073] The mechanical properties of weld metal were tested using a universal tensile testing machine and an instrumented impact testing machine, with the reference testing standard being GB / T 2652.

[0074] Table 4 lists the evaluation results of the all-position welding process performance of the low-spatter gas-shielded solid welding wire rod and welding wire used for all-position automatic welding in Examples 1-5.

[0075] Table 4.

[0076] Example Splash characteristics Welding process stability Yield strength (MPa) Tensile strength (MPa) -10℃ Low-temperature impact energy KV2(J) 1 ● ○ 458 567 266 / 258 / 257 2 ● ○ 479 569 279 / 251 / 255 3 ○ ○ 481 573 269 / 253 / 261 4 ● ○ 529 591 235 / 221 / 224 5 ● ● 537 598 207 / 184 / 188

[0077] Note: In Table 4, ○ indicates excellent and ● indicates good. It should be noted that the -10℃ low-temperature impact energy KV2 was recorded three times.

[0078] As can be seen from Table 4 above, the yield strength of the low-spatter gas-shielded solid welding wire rods and the weld metal of the welding wires used for all-position automatic welding in Examples 1-5 are all between 450 and 550 MPa, the tensile strength is all between 560 and 600 MPa, and the low-temperature impact energy KV2 at -10℃ is all greater than 47 J.

[0079] 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.

[0080] 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 low-spatter gas-shielded solid welding wire rod for all-position automated welding, containing Fe and unavoidable impurities, characterized in that, It also contains the following chemical elements in the following percentages by mass: C: 0.03~0.07%; Si: 0.25~0.55%; Mn: 0.75~1.25%; 0＜S≤0.007％； 0<P≤0.009%; Ti: 0.04~0.12%; Al: 0.02~0.08%; Ca: 0.009~0.05%; Mg: 0.008~0.035%; Cr: 0.04~0.09%; Ce: 0.06~0.25%; Y: 0.05~0.20%; O：0.0085～0.015％。 2. The gas-shielded solid welding wire rod as described in claim 1, characterized in that, Its mass percentage content of each chemical element is as follows: C: 0.03~0.07%; Si: 0.25~0.55%; Mn: 0.75~1.25%; 0＜S≤0.007％； 0<P≤0.009%; Ti: 0.04~0.12%; Al: 0.02~0.08%; Ca: 0.009~0.05%; Mg: 0.008~0.035%; Cr: 0.04~0.09%; Ce: 0.06~0.25%; Y: 0.05~0.20%; O: 0.0085–0.015%; balance is Fe and unavoidable impurities.

3. The gas-shielded solid welding wire rod as described in claim 1 or 2, characterized in that, The unavoidable impurity element mass percentage content meets the following requirement: N≤0.007%.

4. The gas-shielded solid welding wire rod as described in any one of claims 1-3, characterized in that, It also meets the following requirement: the welding spatter rate control coefficient SP ≤ 0.75%; where: Each chemical element in the formula is substituted with its mass percentage content.

5. The gas-shielded solid welding wire rod as described in claim 1 or 2, characterized in that, The microstructure of its deposited metal includes blocky ferrite, acicular ferrite and granular MA components.

6. The gas-shielded solid welding wire rod as described in claim 1 or 2, characterized in that, The properties of the deposited metal meet the following requirements: yield strength of 450-550 MPa, tensile strength of 560-600 MPa, and low-temperature impact energy KV2≥47J at -10℃.

7. A low-spatter gas-shielded solid welding wire for all-position automatic welding, characterized in that, It is made from gas-shielded solid welding wire rod as described in any one of claims 1-6.

8. The gas-shielded solid welding wire as described in claim 7, characterized in that, Its splash rate is ≤8%.

9. An all-position automatic welding process, characterized in that, It is implemented using the gas-shielded solid welding wire as described in claim 7 or 8.

10. The all-position automatic welding process as described in claim 9, characterized in that, Control the welding current to 180–220A, the welding voltage to 19–24V, and the welding speed to 300–450mm / min.

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