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CN-119368968-B - Low-carbon low-alloy welding wire and preparation and welding methods thereof

CN119368968BCN 119368968 BCN119368968 BCN 119368968BCN-119368968-B

Abstract

The invention relates to a low-carbon low-alloy welding wire and a preparation method and a welding method thereof, belongs to the technical field of welding materials, and solves the problems that the existing welding wire is easy to generate defects such as hot cracks, air holes, coarse crystallization and the like when being used for welding high-strength materials, and the strength and low-temperature toughness of weld metal are insufficient, the property matching performance with base materials is poor and the like. The invention provides a low-carbon low-alloy welding wire, wherein the welding wire comprises the components in percentage by mass ：C 0.04～0.08％、Si 0.30～0.50％、Mn 1.6～2.0％、Cr 0.15～0.35％、Ni 3.5～4.0％、Cu 0.008～0.01％、Mo 0.007～0.01％、V 0.0005～0.001％、Ti 0.02～0.07％、Al 0.01～0.018％., the mechanical property and the low-temperature toughness of a welding joint are obviously improved through component design, and the welding wire is particularly suitable for welding P690QL2 steel and is better in welding performance when being used in combination with a matched welding method.

Inventors

  • ZUO YUE
  • AN TONGBANG
  • CAO ZHILONG
  • XU ZIXIN
  • ZHU YANJIE
  • XIAO HONGJUN
  • MA CHENGYONG

Assignees

  • 钢铁研究总院有限公司

Dates

Publication Date
20260508
Application Date
20241128

Claims (10)

  1. 1. A low-carbon low-alloy welding wire for welding P690QL2 steel is characterized by comprising the following components in percentage by mass ：C 0.04～0.08%、Si 0.35～0.45%、Mn 1.75～1.86%、Cr 0.15～0.35%、Ni 3.5～3.8%、Cu 0.008～0.01%、Mo 0.007～0.01%、V 0.0005～0.001%、Ti 0.054～0.056%、Al 0.013～0.018%; When the low-carbon low-alloy welding wire is used for welding, preheating treatment is carried out before welding of a piece to be welded, and the average absorption energy of a welded joint obtained after welding in a 60 ℃ impact test is more than or equal to 130.4J.
  2. 2. The welding wire according to claim 1, wherein the welding wire comprises the following components in percentage by mass ：C 0.04～0.06%、Si 0.35～0.45%、Mn 1.75～1.85%、Cr 0.25～0.30%、Ni 3.6～3.8%、Cu 0.008～0.01%、Mo 0.007～0.01%、V 0.0005～0.001%、Ti 0.054～0.056%、Al 0.013～0.015%.
  3. 3. The welding wire according to claim 1, wherein the welding wire comprises, by mass, 0.051% of C, 0.39% of Si, 1.81% of Mn, 0.28% of Cr, 3.77% of Ni, 0.0097% of Cu, 0.0092% of Mo, 0.0006% of V, 0.055% of Ti, and 0.013% of Al.
  4. 4. A method for preparing a welding wire according to any one of claims 1 to 3, comprising the steps of: S21, ultra-pure smelting, namely, preliminarily weighing and mixing raw materials according to a preset formula, adopting a double smelting technology, firstly, carrying out primary smelting in an electric arc furnace, then refining in an induction furnace to obtain alloy liquid with a preset composition, and pouring and cooling to obtain a casting blank; s22, forging and rolling, namely forging by adopting a gradual cooling technology, and rolling after forging to obtain a welding wire rod; and S23, bright drawing, namely adding a lubricant and drawing the welding wire rod to obtain the low-carbon low-alloy welding wire.
  5. 5. The method according to claim 4, wherein the temperature in the refining step in step S21 is controlled to 1600-1700 ℃ and the maintaining time is 1.5-3 hours, and the vacuum degree is maintained at least 10-3 Torr.
  6. 6. The preparation method of the alloy in the step S22 is characterized in that the specific operation of the forging step is that firstly, the alloy is heated to 850-1050 ℃ through preheating, then the alloy is forged at the initial forging temperature of 1150-1250 ℃, the temperature is controlled by adopting a gradual cooling technology, the alloy is slowly cooled after the forging is finished, the final cooling temperature is more than or equal to 900 ℃, and the application pressure of each forging in the forging step is more than or equal to 120 MPa.
  7. 7. The method according to claim 4, wherein the specific operations and parameters of the rolling step in step S22 are as follows: the rough rolling stage, namely firstly heating the blank to 1100-1150 ℃, wherein the reduction of each rough rolling is 25-35%, and the cooling rate is 40-60 ℃ per hour; In the finish rolling stage, the temperature is kept between 850 and 900 ℃, the rolling reduction of each finish rolling is controlled between 10 and 15 percent, and the cooling rate is controlled between 10 and 20 ℃ per hour.
  8. 8. The method according to claim 4, wherein the drawing speed in the drawing step in step S23 is 5-10 m/min.
  9. 9. The method according to claim 4, further comprising the step of cleaning the surface of the substrate by wiping at step S24 after step S23: And firstly, mechanically wiping the low-carbon low-alloy welding wire, and then performing ultrasonic cleaning to remove microscopic impurities.
  10. 10. A welding method of a welding wire according to any one of claims 1 to 3 or a welding wire obtained by the preparation method according to any one of claims 4 to 9, characterized in that a consumable part is welded by using the welding wire by adopting a consumable electrode active gas shielded welding process in a shielding gas of 95% argon+5% carbon dioxide by volume.

Description

Low-carbon low-alloy welding wire and preparation and welding methods thereof Technical Field The invention relates to the technical field of welding materials, in particular to a low-carbon low-alloy welding wire and a preparation method and a welding method thereof. Background With the worldwide increasing demand for liquefied carbon dioxide storage and transportation, low temperature, high pressure storage tanks are becoming critical devices. However, most of the liquefied carbon dioxide tank materials currently used are steel materials having relatively low yield strength, such as 07MnNiMoVDR (yield strength 490 MPa) and 15MnNbR (yield strength 370 MPa). Although the materials can meet the requirements of common low-temperature storage tanks, the materials often have defects such as limited strength and unsatisfactory impact resistance under the high-pressure and low-temperature limit working conditions such as liquefied carbon dioxide storage tanks, so that the bearing capacity and the safety of the storage tanks are difficult to reach the optimal state. To achieve a higher storage capacity of the tank per unit volume, the choice of materials with higher strength levels is a necessary trend. The 690 MPa-grade high-strength low-temperature steel P690QL2 has excellent low-temperature toughness and high-strength performance, and is one of ideal materials for manufacturing liquefied carbon dioxide storage tanks. The P690QL2 steel can effectively reduce the wall thickness of the storage tank and lighten the structure weight, thereby improving the storage efficiency and the economic benefit of the storage tank on the premise of not increasing the cost. Furthermore, the use of such high strength materials allows for a higher safety margin for the tank when faced with high pressure conditions. However, the technical challenges of P690QL2 steel in welding processes are significant. Because of the high strength of the material, defects such as hot cracks, air holes, coarse crystallization and the like are easy to generate in the welding process, and the defects can influence the toughness and mechanical properties of the welded joint, in particular the impact resistance under the low-temperature environment. The low-temperature toughness and impact resistance of weld metal formed by the existing welding wire are poor, and the special requirements of a liquefied carbon dioxide storage tank are difficult to meet. Disclosure of Invention In view of the above analysis, the embodiment of the invention aims to provide a low-carbon low-alloy welding wire and a preparation method and a welding method thereof, which are used for solving the problems that the existing welding wire is easy to generate defects such as hot cracks, air holes, coarse crystallization and the like when being used for welding high-strength materials, and the strength and low-temperature toughness of weld metal are insufficient, and the property of the weld metal and the base metal are not good in matching. The invention provides a low-carbon low-alloy welding wire, which comprises the following components in percentage by mass ：C 0.04～0.08％、Si 0.30～0.50％、Mn 1.6～2.0％、Cr 0.15～0.35％、Ni 3.5～4.0％、Cu 0.008～0.01％、Mo 0.007～0.01％、V 0.0005～0.001％、Ti 0.02～0.07％、Al 0.01～0.018％. Preferably, the welding wire comprises the following components in percentage by mass ：C 0.04～0.06％、Si0.35～0.45％、Mn 1.75～1.85％、Cr 0.25～0.30％、Ni 3.6～3.8％、Cu0.008～0.01％、Mo 0.007～0.01％、V 0.0005～0.001％、Ti 0.04～0.06％、Al 0.013～0.015％. More preferably, the welding wire comprises, by mass, 0.051% of C, 0.39% of Si, 1.81% of Mn, 0.28% of Cr, 3.77% of Ni, 0.0097% of Cu, 0.0092% of Mo, 0.0006% of V, 0.055% of Ti and 0.013% of Al. The invention also provides a preparation method of the welding wire, which comprises the following steps: S21, ultra-pure smelting, namely, preliminarily weighing and mixing raw materials according to a preset formula, adopting a double smelting technology, firstly, carrying out primary smelting in an electric arc furnace, then refining in an induction furnace to obtain alloy liquid with a preset composition, and pouring and cooling to obtain a casting blank; s22, forging and rolling, namely forging by adopting a gradual cooling technology, and rolling after forging to obtain a welding wire rod; and S23, bright drawing, namely adding a lubricant and drawing the welding wire rod to obtain the low-carbon low-alloy welding wire. Further, in the step S21, the temperature in the refining step is controlled to 1600-1700 ℃, the maintaining time is 1.5-3 hours, and the vacuum degree is kept at least 10-3 Torr. Further, the specific operation of the forging step in the step S22 is that firstly, the alloy is heated to 850-1050 ℃ through preheating, then, forging is carried out at the initial forging temperature of 1150-1250 ℃, the temperature control is carried out by applying a gradual cooling technology, the alloy is slowly cooled after the forging is finished, the final cooli