Gas-shielded high-strength welding wire steel wire rod and short-process low-phosphorus low-nitrogen preparation method thereof

Abstract

The invention relates to a gas-shielded high-strength welding wire steel wire rod and a short-process low-phosphorus and low-nitrogen preparation method thereof. The mass content of phosphorus is smaller than 0.005%, the mass content of carbon is 0.03-0.07%, and the mass content of nitrogen is smaller than 0.005% at the smelting end point of an electric arc furnace. According to the invention, the final temperature and component control of the electric furnace smelting process is utilized to ensure the final molten steel component of electric furnace smelting, thereby reducing the risks of overlong refining time and phosphorus content increase caused by adding a large amount of alloy in LF refining. And secondly, efficient and deep dephosphorization in the smelting process is achieved by improving slagging, oxygen supply and power supply systems in the electric furnace smelting process, and nitrogen suction caused by electrification is reduced.

Description

Technical Field

[0001] The invention relates to a gas-shielded high-strength welding wire steel wire rod and a short-process low-phosphorus and low-nitrogen preparation method thereof, belonging to the technical field of gas-shielded high-strength welding wire steel production. Background Art

[0002] Gas-shielded high-strength welding wire steel achieves high strength, low-temperature toughness, and corrosion resistance through optimized alloy design. It meets the needs of a wide range of industries, from conventional industries to extreme environments, and is widely used in engineering machinery, automotive manufacturing, marine and offshore, and petrochemical industries. Due to the specific performance requirements of gas-shielded high-strength welding wire steel, alloying elements such as nickel, chromium, and molybdenum are added, and there are also high requirements for the content of impurity elements such as phosphorus and nitrogen in the steel. Traditionally, high-quality welding wire steel is generally produced using a blast furnace-KR hot metal pretreatment-converter-refining-continuous casting process, which is a long production process and has high carbon emissions. For example, patent application publication number CN118848336A provides a gas-shielded welding wire, gas-shielded welding wire steel wire rod, and a production method for the same. This method improves the performance of gas-shielded high-strength welding wire steel by optimizing alloy composition design and controlling the steelmaking and rolling processes during the long converter production process. In recent years, the use of short-process electric arc furnaces to produce high-quality welding wire steel has gradually increased. For example, the patent application with publication number CN105063474A provides an electric arc furnace smelting method for welding wire steel. This method achieves short-process low-phosphorus smelting of welding wire steel by optimizing the electric arc furnace slag formation system, temperature system, and slag flow system. However, at present, high-quality gas-shielded high-strength welding wire steel is mainly produced using a long converter process. The control of phosphorus and nitrogen in the steel is relatively easy, but there are problems with the long production process and high carbon emissions. When using the electric arc furnace short process for production, there is a problem of controlling impurity elements such as phosphorus and nitrogen. Summary of the Invention

[0003] In order to solve the above problems, the present invention discloses a gas-shielded high-strength welding wire steel wire rod and a short-process low-phosphorus and low-nitrogen preparation method thereof. The specific technical solution is as follows: A short-process low-phosphorus and low-nitrogen preparation method for gas-shielded high-strength welding wire steel adopts an electric arc furnace smelting-LF refining-small square billet continuous casting-high-strength wire rolling process, specifically comprising the following steps: Step 1: Electric Arc Furnace Smelting: Add molten iron, scrap steel and ferronickel into the furnace. Add ferronickel into the scrap steel bag and add it into the furnace together with the scrap steel. Add crushed material to the bottom of the scrap steel bag, add ferronickel to the middle and lower part of the scrap steel bag, add heavy scrap steel to the middle and upper part of the scrap steel bag, and add crushed material to the top of the scrap steel bag. Step 2: After the arc furnace smelting is completed, the arc furnace final tapping temperature is greater than 1620 ° C, the final phosphorus mass content is less than 0.005%, the final carbon mass content is 0.03%~0.07%, and the final nitrogen mass content is less than 0.005%; Step 3: When the electric arc furnace is one-third full of steel, start adding 900-950 kg of low-titanium and low-aluminum ferrosilicon, 1500-1550 kg of low-carbon ferromanganese, and 300-350 kg of lime; when the electric arc furnace is finished tapping, add 700-750 kg of ferromolybdenum into the ladle; Step 4: The ladle is hoisted into the LF refining station and temperature measurement and sampling are started; the power is turned on to increase the temperature, and 100-150 kg of calcium carbide is added to diffuse and deoxidize the slag; 300-400 kg of lime is added, and the bottom blowing argon flow rate is controlled at 600-800 NL / min; Step 5: Based on the composition results of the molten steel sample, nickel plate and low-carbon ferrochrome, as well as the remaining low-titanium and low-aluminum ferrosilicon, low-carbon ferromanganese and ferromolybdenum from step 3, are added to adjust the composition. The bottom blowing flow rate is controlled at 400~600NL / min. Step 6: After the silicon, manganese, nickel, chromium and molybdenum components in the steel are qualified, feed 400~450m of titanium wire, and control the bottom blowing flow rate at 150~250 NL / min; Step 7: After the composition adjustment is completed, gradually reduce the argon blowing from the bottom of the ladle to a soft stirring state. The argon flow rate is 40 ~ 100NL / min, with slight fluctuations on the slag surface. The soft stirring time is 15min ~ 16min. Step 8: Casting using a billet continuous caster; Step 9: High-speed wire rolling process: The soaking temperature during heating is 1120℃~1160℃, the finishing rolling temperature is 930℃~970℃, and the spinning temperature is 810℃~850℃.

[0004] Furthermore, the specific process of the electric arc furnace smelting in step 1 is as follows: Step 1.1: After the molten iron is added into the electric arc furnace, the furnace wall gun is opened for blowing. The total oxygen flow rate of the furnace wall gun is 3500~3600Nm 3 / h; After the molten iron is added, the oxygen injection flow rate of the furnace wall gun is controlled at 5400~5500Nm 3 / h, the oxygen spray flow rate of the furnace door gun is controlled at 2000~2200Nm 3 / h; Step 1.2: Electric arc furnace smelting, oxygen consumption reaches 800Nm 3 Then, the electrodes are lowered and energized, with the voltage level at level 10 and the current level at level 5, controlling the active power to 40~45MW. Step 1.3: Electric arc furnace smelting: After the start of electric arc furnace smelting, add 400-500 kg of lime and 400-500 kg of light-burned dolomite from the high-level silo. Thereafter, add 400-500 kg of lime every 2 minutes. Step 1.4: After the scrap steel is melted in the electric arc furnace, temperature measurement and sampling are started. When the molten pool temperature is greater than 1520℃, the oxygen flow rate of the furnace wall gun is controlled at 4200~4300Nm 3 / h, the oxygen spray flow rate of the furnace door gun is controlled at 1500~2000Nm 3 / h; add 400~500kg lime every 2~3min; Step 1.5: After the scrap steel is melted, the temperature is greater than 1520°C, the voltage level is controlled at level 8, the current level is controlled at level 5, and the active power is controlled at 35-40MW; Step 1.6: After the scrap steel is melted in the electric arc furnace, the furnace wall gun starts to spray carbon powder to ensure that the height of the foam slag at the furnace door is 1 / 2 to 2 / 3 of the furnace door height.

[0005] Furthermore, in step 1, the mass of the molten iron entering the furnace is 70t~75t, the amount of scrap steel added is 30t~35t, and the amount of ferronickel added is 11t~13t; Add 8t-10t of crushed material to the bottom of the scrap steel bag, and control the bulk density at 0.8-1.0; add 11t-13t of ferronickel to the lower middle part of the scrap steel bag; add 10t-13t of heavy scrap steel to the upper middle part of the scrap steel bag, and control the bulk density at 1.3-1.5; add 10t-12t of crushed material to the upper part of the scrap steel bag, and control the bulk density at 0.6-0.8; The thickness of scrap steel entering the furnace is ≥3.0mm, the S mass content in the scrap steel is ≤0.025%, the Cu mass content is ≤0.05%, and the Al mass content is ≤0.03%; the molten iron temperature is >1350℃, the S mass content in the molten iron is <0.005%, and the P mass content is <0.09%.

[0006] Furthermore, in the electric arc furnace smelting process in step 1, the mass content of some elements in the nickel iron entering the furnace is 8%≤Ni≤12%, P≤0.06%, S≤0.5%, C≤4.0%, and Si≤5.0%.

[0007] Furthermore, the lime addition in the electric arc furnace smelting process is controlled at 50-55 kg / t, and the power consumption is controlled at 70-90 kWh / t.

[0008] Furthermore, in the electric arc furnace smelting process, the slag basicity is controlled at 1.8-2.3 before the scrap steel is melted clean, and the slag basicity is controlled at 3.5-4.0 after the scrap steel is melted clean.

[0009] Furthermore, during the electric arc furnace smelting process, the carbon powder injection flow rate of the furnace wall gun is controlled at 60-70 kg / min, and the carbon powder consumption is controlled at 10-12 kg / t.

[0010] Furthermore, the step 8 is specifically as follows: before pouring, argon is blown into the tundish for more than 5 minutes, the immersion nozzle is inserted to a depth of 90 to 140 mm, and the immersion nozzle is ensured to be centered, with a deviation of less than 5 mm from the center line of the crystallizer copper tube; Use low-carbon steel mold slag for small square billets, and control the thickness of the mold slag layer to 8~10mm; Control the superheat of molten steel in the tundish to 30℃~50℃; The crystallizer was stirred with electromagnetic stirring, the current was 300~400A, the frequency was 4~6Hz, and the water flow rate of the crystallizer was controlled at 1725±25L / min.

[0011] Furthermore, the continuous casting machine is a straight arc continuous casting machine, and the cross-sectional size of the continuous casting billet is 140 mm × 140 mm; The tonnage of the continuous casting tundish is ≥20t when starting to pour, ≥35t when pouring normally, and ≥38t when changing tundishes during continuous casting; During the continuous casting process, the argon sealing pressure of the ladle long nozzle is 0.2-0.3 MPa, and the continuous casting billet drawing speed is controlled at 2.4-2.6 m / min.

[0012] A gas-shielded high-strength welding wire steel wire rod, which is obtained by the above-mentioned gas-shielded high-strength welding wire steel short-process low-phosphorus and low-nitrogen preparation method; Calculated in mass percentage, the gas-shielded high-strength welding wire steel, in addition to Fe element and inevitable impurities, also includes the following chemical components, calculated in mass percentage: C: 0.08%~0.1%, Si: 0.55%~0.66%, Mn: 1.65%~1.80%, Cr: 0.15%~0.25%, Mo: 0.45%~0.55%, Ni: 1.45%~1.55%, V≤0.02%, Al≤0.008%, S: 0.008%~0.016%, and P≤0.01%.

[0013] The working principle of the present invention is: Due to the special performance requirements of high-quality gas shielded welding wire steel, it is usually necessary to add alloy elements such as nickel, chromium and molybdenum, and at the same time, there are high requirements for the content of impurity elements such as phosphorus and nitrogen in the steel. At present, high-quality gas shielded welding wire steel is mainly produced by the long converter process. The control of phosphorus and nitrogen in the steel is relatively easy, but there are problems of long production process and high carbon emissions. When the electric furnace short process is used for production, there is a problem of controlling impurity elements such as phosphorus and nitrogen. The present invention improves the production process of gas shielded welding wire steel by systematically using the electric furnace-LF refining-small square billet continuous casting-high wire rolling process for production. The key points of the entire process are as follows: (1) In view of the problem that the content of alloy elements in gas shielded welding wire steel is high and a large amount of alloy is added in the LF refining station during conventional production, which makes it difficult to control the phosphorus content in the steel and the refining time is too long, some non-oxidizing alloys are added into the furnace together with scrap steel in the electric furnace process in the form of raw materials. The advantages of precise terminal temperature control and efficient dephosphorization when the electric furnace is powered on and heated are fully utilized, which solves the problem of difficult phosphorus content control and long refining time caused by the large amount of alloy added in high-quality welding wire steel, and at the same time reduces the alloy cost.

[0014] (2) In the electric arc furnace smelting process, in order to improve the dephosphorization effect, before the scrap steel is melted, the oxygen flow rate of the furnace wall gun and the furnace door gun is controlled. The impact of the oxygen jet on the molten pool and the stirring effect of the gas generated by the decarburization reaction are used to accelerate the mass transfer of phosphorus to the steel slag interface. At the same time, the amount and frequency of lime addition are controlled to accelerate the melting of lime into slag and control the slag alkalinity at 1.8-2.3 to achieve rapid dephosphorization. After the scrap steel is melted, the power supply voltage and current level are controlled to slow down the temperature rise of the molten steel and prevent the deterioration of the molten pool stirring effect caused by power outages. Furthermore, the amount and frequency of lime addition are optimized to control the slag alkalinity at 3.5-4.0 to achieve enhanced dephosphorization in the later stage of smelting.

[0015] (3) In the electric arc furnace smelting process, in order to control the nitrogen absorption of molten steel after the scrap steel is melted, a continuous carbon powder spraying process is adopted on the furnace wall. By optimizing the carbon powder spraying amount, continuous and good foam slag is ensured, and the foam slag height covers 1 / 2 to 2 / 3 of the furnace door. At the same time, the voltage and current gears are optimized to reduce the arc length, thereby achieving good arc coverage and reducing the nitrogen absorption of molten steel.

[0016] (4) In the early stage of the refining process, the composition is quickly adjusted, and appropriate amounts of calcium carbide and lime are added to control the oxidizability and alkalinity of the slag. After the composition adjustment is completed, the bottom blowing argon gas size is adjusted to perform soft stirring to promote the floating removal of inclusions.

[0017] The beneficial effects of the present invention are: The present invention systematically improves the production process of high-quality welding wire steel, takes advantage of the precise control of the terminal temperature and composition of the electric arc furnace smelting process, optimizes the amount of scrap steel, molten iron and alloy added to the raw materials entering the furnace, ensures the composition of the molten steel at the end of the electric arc furnace smelting, and thus reduces the risk of long refining time and increased phosphorus content caused by the addition of a large amount of alloys in LF refining. Secondly, by improving the slag making, oxygen supply and power supply system of the electric arc furnace smelting process, efficient deep dephosphorization of the smelting process is achieved, reducing the inhalation of nitrogen caused by power on. Further control of the refining, continuous casting and rolling processes to obtain high-quality welding wire steel coils, the tensile strength of the weld metal obtained by the deposited metal test using the welding wire is ≥800MPa, and the low-temperature impact energy of -40°C is ≥110J. DETAILED DESCRIPTION

[0018] The present invention will be further described below in conjunction with specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0019] Two specific application examples of the present invention are given below: The electric arc furnace smelting adopts the method of adding one bag of molten iron and one bag of scrap steel. The scrap steel is added into the furnace from the material bag, and the molten iron is added into the furnace from the molten iron chute at the back of the furnace. The specific amount of scrap steel added is shown in Table 1: Table 1

[0020] The chemical composition of the scrap steel entering the furnace is S content ≤ 0.025%, Cu content ≤ 0.05%, Al content ≤ 0.03%, and the thickness of the scrap steel is ≥ 3.0mm. After the scrap steel is added, the molten iron is added and the furnace wall oxygen lance is opened for blowing. The total flow rate of the furnace wall oxygen lance is controlled at 3500-3600Nm 3 / h. After the molten iron is added, the flow rate of the furnace wall gun is controlled at 5400-5500Nm 3 / h, the furnace door gun flow rate is controlled at 2000-2200Nm 3 / h. At the same time, 400kg of lime and 500kg of light burnt are added from the high-level silo, and 400kg of lime is added every 2 minutes thereafter. The oxygen consumption reaches 800Nm 3 After that, the electrode is lowered and energized, with the voltage gear at gear 10 and the current gear at gear 5. After the scrap steel is melted, temperature measurement and sampling are started. When the molten pool temperature is greater than 1520℃, the flow rate of the furnace wall gun is controlled at 4200-4300Nm 3 / h, the furnace door gun flow rate is controlled at 1500-2000Nm 3 / h. 400kg of lime was added every 2-3 minutes. The voltage was controlled at level 8, and the current at level 5. Carbon powder was sprayed from the furnace wall guns, with the flow rate maintained at 60-70kg / min. The tapping temperature of the electric arc furnace and the final carbon, phosphorus, and nitrogen contents are shown in Table 2: Table 2

[0021] When the electric arc furnace is one-third full, low-titanium, low-aluminum ferrosilicon, low-carbon ferromanganese and lime are added. When the electric arc furnace is finished tapping, ferromolybdenum is added to the ladle, as shown in Table 3: Table 3

[0022] The ladle is hoisted into the LF refining station and the power is turned on to increase the temperature. Calcium carbide is added to diffuse and deoxidize the slag. Lime is added to control the slag basicity and the bottom blowing argon flow rate, as shown in Table 4: Table 4

[0023] Temperature measurement and sampling are performed. Based on the composition requirements of the molten steel sample, the remaining low-titanium, low-aluminum ferrosilicon, low-carbon ferromanganese, nickel plate, ferromolybdenum, and low-carbon ferrochrome are added. Once the composition is adjusted, titanium wire is added to control the molten steel temperature within the appropriate range. Soft stirring is performed to remove inclusions. The argon gas flow from the ladle bottom is gradually reduced to achieve a soft stirring state, and the soft stirring time is controlled.

[0024] Table 5

[0025] The continuous casting machine then enters the pouring process, with the cross-sectional dimensions of the continuous casting billet being 140 mm × 140 mm. The tundish tonnage for the start of continuous casting is set at 20 t, the tundish tonnage for normal pouring is 35 t, and the tundish tonnage for continuous casting and ladle replacement is 38 t. The tundish steel superheat is controlled at 40°C, the continuous casting speed is controlled at 2.5 m / min, and the mold protective slag layer thickness, shroud argon seal pressure, mold electromagnetic current, mold frequency, and mold water volume are shown in Table 6: Table 6

[0026] In the rolling process, the rolling heating temperature, finishing rolling temperature and spinning temperature are set as shown in Table 7: Table 7

[0027] The content of some elements in the final gas shielded high-strength welding wire steel wire rod is shown in Table 8: Table 8

[0028] From Table 8, we can see the element limitations of high-quality welding steel wire rod.

[0029] The properties of the weld metals obtained by conducting deposited metal tests on the welding wires obtained in Examples 1 and 2 are shown in Table 9: Table 9

[0030] It can be seen from Table 9 that the welding wires of Examples 1 and 2 meet the requirements of high-quality welding wire steel wire rods.

[0031] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art and, unless defined as such, will not be interpreted in an idealized or overly formal sense.

[0032] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A method for preparing gas-shielded high-strength welding wire steel with low phosphorus and low nitrogen in a short process, characterized in that: The production process adopts electric arc furnace smelting - LF refining - billet continuous casting - high-speed wire rolling, which specifically includes the following steps: Step 1: Electric Arc Furnace Smelting: Add molten iron, scrap steel and ferronickel into the furnace. Add ferronickel into the scrap steel bag and add it into the furnace together with the scrap steel. Add crushed material to the bottom of the scrap steel bag, add ferronickel to the middle and lower part of the scrap steel bag, add heavy scrap steel to the middle and upper part of the scrap steel bag, and add crushed material to the top of the scrap steel bag. Step 2: After the arc furnace smelting is completed, the arc furnace final tapping temperature is greater than 1620 ° C, the final phosphorus mass content is less than 0.005%, the final carbon mass content is 0.03%~0.07%, and the final nitrogen mass content is less than 0.005%; Step 3: When the electric arc furnace is one-third full of steel, start adding 900-950 kg of low-titanium and low-aluminum ferrosilicon, 1500-1550 kg of low-carbon ferromanganese, and 300-350 kg of lime; when the electric arc furnace is finished tapping, add 700-750 kg of ferromolybdenum into the ladle; Step 4: The ladle is hoisted into the LF refining station and temperature measurement and sampling are started; the power is turned on to increase the temperature, and 100-150 kg of calcium carbide is added to diffuse and deoxidize the slag; 300-400 kg of lime is added, and the bottom blowing argon flow rate is controlled at 600-800 NL / min; Step 5: Based on the composition results of the molten steel sample, nickel plate and low-carbon ferrochrome, as well as the remaining low-titanium and low-aluminum ferrosilicon, low-carbon ferromanganese and ferromolybdenum from step 3, are added to adjust the composition. The bottom blowing flow rate is controlled at 400~600NL / min. Step 6: After the silicon, manganese, nickel, chromium and molybdenum components in the steel are qualified, feed 400~450m of titanium wire, and control the bottom blowing flow rate at 150~250 NL / min; Step 7: After the composition adjustment is completed, gradually reduce the argon blowing from the bottom of the ladle to a soft stirring state. The argon flow rate is 40 ~ 100NL / min, and the slag surface fluctuates slightly. The soft stirring time is 15min ~ 16min; Step 8: Casting using a billet continuous caster; Step 9: High-speed wire rolling process: The soaking temperature during heating is 1120℃~1160℃, the finishing rolling temperature is 930℃~970℃, and the spinning temperature is 810℃~850℃.

2. The method for preparing gas shielded high-strength welding wire steel with short process and low phosphorus and low nitrogen according to claim 1, characterized in that: The specific process of electric arc furnace smelting in step 1 is as follows: Step 1.1: After the molten iron is added into the electric arc furnace, the furnace wall gun is opened for blowing. The total oxygen flow rate of the furnace wall gun is 3500~3600Nm 3 / h; After the molten iron is added, the oxygen injection flow rate of the furnace wall gun is controlled at 5400~5500Nm 3 / h, the oxygen spray flow rate of the furnace door gun is controlled at 2000~2200Nm 3 / h; Step 1.2: Electric arc furnace smelting, oxygen consumption reaches 800Nm 3 Then, the electrodes are lowered and energized, with the voltage level at level 10 and the current level at level 5, controlling the active power to 40~45MW. Step 1.3: Electric arc furnace smelting: After the start of electric arc furnace smelting, add 400-500 kg of lime and 400-500 kg of light-burned dolomite from the high-level silo. Thereafter, add 400-500 kg of lime every 2 minutes. Step 1.4: After the scrap steel is melted in the electric arc furnace, temperature measurement and sampling are started. When the molten pool temperature is greater than 1520℃, the oxygen flow rate of the furnace wall gun is controlled at 4200~4300Nm 3 / h, the oxygen spray flow rate of the furnace door gun is controlled at 1500~2000Nm 3 / h; add 400~500kg lime every 2~3min; Step 1.5: After the scrap steel is melted, the temperature is greater than 1520°C, the voltage level is controlled at level 8, the current level is controlled at level 5, and the active power is controlled at 35-40MW; Step 1.6: After the scrap steel is melted in the electric arc furnace, the furnace wall gun starts to spray carbon powder to ensure that the height of the foam slag at the furnace door is 1 / 2 to 2 / 3 of the furnace door height.

3. The method for preparing gas shielded high-strength welding wire steel with short process and low phosphorus and low nitrogen according to claim 1, characterized in that: In the step 1, the mass of the molten iron entering the furnace is 70t~75t, the amount of scrap steel added is 30t~35t, and the amount of ferronickel added is 11t~13t; Add 8t-10t of crushed material to the bottom of the scrap steel bag, and control the bulk density at 0.8-1.0; add 11t-13t of ferronickel to the lower middle part of the scrap steel bag; add 10t-13t of heavy scrap steel to the upper middle part of the scrap steel bag, and control the bulk density at 1.3-1.5; add 10t-12t of crushed material to the upper part of the scrap steel bag, and control the bulk density at 0.6-0.8; The thickness of scrap steel entering the furnace is ≥3.0mm, the S mass content in the scrap steel is ≤0.025%, the Cu mass content is ≤0.05%, and the Al mass content is ≤0.03%; the molten iron temperature is >1350℃, the S mass content in the molten iron is <0.005%, and the P mass content is <0.09%.

4. The method for preparing gas shielded high-strength welding wire steel with short process and low phosphorus and low nitrogen according to claim 1, characterized in that: In the electric arc furnace smelting process in step 1, the mass content of some elements in the nickel iron entering the furnace is 8%≤Ni≤12%, P≤0.06%, S≤0.5%, C≤4.0%, and Si≤5.0%.

5. The method for preparing gas shielded high-strength welding wire steel with short process and low phosphorus and low nitrogen according to claim 1, characterized in that: In the electric arc furnace smelting process, the lime addition is controlled at 50-55 kg / t, and the power consumption is controlled at 70-90 kWh / t.

6. The method for preparing gas shielded high-strength welding wire steel with short process and low phosphorus and low nitrogen according to claim 1, characterized in that: In the electric arc furnace smelting process, the slag basicity is controlled at 1.8-2.3 before the scrap steel is melted clean, and the slag basicity is controlled at 3.5-4.0 after the scrap steel is melted clean.

7. The method for preparing gas shielded high-strength welding wire steel with short process and low phosphorus and low nitrogen according to claim 1, characterized in that: During the electric arc furnace smelting process, the carbon powder injection flow rate of the furnace wall gun is controlled at 60-70 kg / min, and the carbon powder consumption is controlled at 10-12 kg / t.

8. The method for preparing gas shielded high-strength welding wire steel with short process and low phosphorus and low nitrogen according to claim 1, characterized in that: The step 8 specifically includes: blowing argon into the tundish for more than 5 minutes before pouring, inserting the submerged nozzle to a depth of 90-140 mm, and ensuring that the submerged nozzle is centered and the deviation from the center line of the crystallizer copper tube is less than 5 mm; Use low-carbon steel mold slag for small square billets, and control the thickness of the mold slag layer to 8~10mm; Control the superheat of molten steel in the tundish to 30℃~50℃; The crystallizer was stirred with electromagnetic stirring, the current was 300~400A, the frequency was 4~6Hz, and the water flow rate of the crystallizer was controlled at 1725±25L / min.

9. The method for preparing gas shielded high-strength welding wire steel with short process and low phosphorus and low nitrogen according to claim 1, characterized in that: The continuous casting machine is a straight arc continuous casting machine, and the cross-sectional size of the continuous casting billet is 140mm×140mm; The tonnage of the continuous casting tundish is ≥20t when starting to pour, ≥35t when pouring normally, and ≥38t when changing tundishes during continuous casting; During the continuous casting process, the argon sealing pressure of the ladle long nozzle is 0.2-0.3 MPa, and the continuous casting billet drawing speed is controlled at 2.4-2.6 m / min.

10. A gas-shielded high-strength welding wire steel wire rod, characterized in that: The gas shielded high-strength welding wire steel is obtained by the short-process low-phosphorus and low-nitrogen preparation method according to any one of claims 1 to 9; Calculated in mass percentage, the gas-shielded high-strength welding wire steel, in addition to Fe element and inevitable impurities, also includes the following chemical components, calculated in mass percentage: C: 0.08%~0.1%, Si: 0.55%~0.66%, Mn: 1.65%~1.80%, Cr: 0.15%~0.25%, Mo: 0.45%~0.55%, Ni: 1.45%~1.55%, V≤0.02%, Al≤0.008%, S: 0.008%~0.016%, and P≤0.01%.

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