WO2022236975A1 - High-manganese steel wire rod for welding and steel rolling process therefor - Google Patents

High-manganese steel wire rod for welding and steel rolling process therefor Download PDF

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WO2022236975A1
WO2022236975A1 PCT/CN2021/110537 CN2021110537W WO2022236975A1 WO 2022236975 A1 WO2022236975 A1 WO 2022236975A1 CN 2021110537 W CN2021110537 W CN 2021110537W WO 2022236975 A1 WO2022236975 A1 WO 2022236975A1
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temperature
wire rod
steel wire
welding
manganese steel
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PCT/CN2021/110537
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French (fr)
Chinese (zh)
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黄一新
谯明亮
孙超
闫旭强
肖丙政
范益
李东晖
赵柏杰
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南京钢铁股份有限公司
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Publication of WO2022236975A1 publication Critical patent/WO2022236975A1/en

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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
    • C21D8/065—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/001—Austenite

Definitions

  • the invention belongs to the technical field of metal materials, and in particular relates to a high manganese steel wire rod for welding and a steel rolling process thereof.
  • the temperatures for obtaining liquefied ethylene, liquefied natural gas, liquid hydrogen, and liquid helium under normal pressure are -104°C, -162°C, -253°C, and -269°C, respectively.
  • the mechanical properties of storage and transportation container materials are extremely high, especially Impact toughness at low temperatures. At present, the lowest temperature can reach -269°C and low-temperature steels such as S30403 and S31603 stainless steel are widely used.
  • the Ni content of stainless steel wire rods used in the manufacture of supporting welding materials such as H06Cr21Ni10 and H06Cr19Ni12Mo2 are all above 10%.
  • High-manganese low-temperature steel has attracted much attention as a new generation of nickel-saving low-temperature steel, but its composition system is special and the process control is difficult.
  • South Korea’s POSCO has successfully developed high-manganese low-temperature steel plates and welding consumables that can be used in the storage and transportation of liquefied natural gas and has entered the stage of application and promotion.
  • the country is still in the development stage in general, and the nickel-saving welding consumables that match high-manganese low-temperature steel The research and development of the steel plate needs to be accelerated simultaneously.
  • the present invention provides a high-manganese steel wire rod for welding, which can be used as the steel raw material for manufacturing high-manganese low-temperature steel matching welding consumables, and the steel wire rod itself has excellent plasticity,
  • the formed deposited metal has excellent low temperature toughness.
  • Another object of the present invention is to provide a steel rolling process for the above-mentioned high manganese steel wire rod for welding.
  • a high manganese steel wire rod for welding according to the present invention is characterized in that the composition contains C: 0.3-0.5%, Mn: 26.5-32.5%, Ni: 4-5.5%, Cr : 4 to 6%, Si ⁇ 0.2%, P ⁇ 0.012%, S ⁇ 0.008%, and the balance contains Fe and unavoidable impurities.
  • the high manganese steel wire rod for welding also contains one or more of Cu ⁇ 0.6%, Mo ⁇ 0.6%, V ⁇ 0.3%, Al ⁇ 0.1%, Ti ⁇ 0.1%, N ⁇ 0.05% element instead of a part of the Fe.
  • Austenitic structure has excellent strength, plasticity, toughness matching and lower service temperature. Although adding a high content of Ni can obtain an austenitic structure, such as 304 austenitic stainless steel, etc., the economy is poor, so it is necessary to use a variety of alloying elements that can stabilize austenite.
  • C, Mn, and Ni are all austenite forming elements, and can reduce the martensite transformation temperature, which is beneficial to improve the stability of austenite.
  • Cr is a ferrite forming element, it can lower the martensitic transformation temperature, so it is also beneficial to improve the stability of austenite.
  • the stability of austenite is measured by the stability factor:
  • Austenite stability factor 35C+0.5Mn+Ni-0.0833(Cr-20) 2 -12.
  • the invention controls the lower limit of the addition amount of C, Mn, Ni and Cr to make the austenite stability coefficient ⁇ -5.6 and ensure sufficient austenite stability.
  • the content of the above four elements exists in the expression of the austenite stability coefficient, C has the strongest austenite stabilizing effect.
  • the present invention considers that low-temperature steel does not have special requirements for corrosion resistance under many service conditions, so it does not control the very low C content like the design of stainless steel alloys, but adopts the design of medium and high C above 0.3% to improve the corrosion resistance. body stability.
  • the increase of C content leads to the increase of the critical temperature of carbide precipitation, which narrows the process window of hot rolling and heat treatment of wire rod, and also increases the tendency of carbide precipitation during welding, so the upper limit of the content needs to be controlled.
  • controlling the C content within 0.5% can make the carbide precipitation critical temperature lower than 900°C.
  • Ni has a high austenite stabilization effect, and Ni is a non-carbide forming element. Adding a certain amount of Ni is beneficial to obtain better low temperature performance. A large amount of Ni element is added to the composition of 304 stainless steel and other materials. Although it also has certain low-temperature toughness, the starting point of its content design is to control the structure type and obtain high corrosion resistance. When the material is used as a structural material in a low temperature environment, especially when it is used as a structural material for liquefied ethylene, liquefied natural gas, liquid hydrogen and liquid helium storage and transportation containers in an extremely low temperature environment from -104°C to -269°C, it is not suitable for the material Corrosion resistance is required. Therefore, the present invention reduces the Ni content in the composition design and controls the Ni content within the range of 4-5.5%. Sufficient austenite stability is ensured by the content of the elements Mn and Cr after the reduced Ni content.
  • Mn is half that of Ni, which can be seen from the coefficient difference of different elements in the stability coefficient expression. Therefore, reducing the Ni content requires adding more Mn to ensure sufficient austenite stability.
  • Mn is cheap, but too much Mn alloy content will increase the difficulty of industrial smelting, narrow the rolling process window, and increase the Mn content of welding fumes.
  • Another important basis for determining the addition amount of Mn in the present invention is to control the stacking fault energy of austenite.
  • the present invention further determines the Mn content to be 26.5-32.5% on the basis of the C content, and controls the stacking fault energy of the austenite within the temperature range of 20°C to -269°C to 17-46mJ/ m2 , thereby obtaining the best cladding Metal mechanical properties.
  • the content of Cr element is within 20%, the stability of austenite increases as the content increases. Therefore, adding a certain amount of Cr element is also beneficial to reduce the requirement of Ni.
  • the effect of unit content of Cr element on improving the stability of austenite is weakened.
  • the Cr element is easy to form carbides. Excessively high Cr content increases the critical temperature of carbide precipitation and the volume fraction of carbide precipitation, which is not conducive to the improvement of the low-temperature impact toughness of the deposited metal.
  • the present invention controls the Cr content to 4-6%, which is far lower than the Cr content in 304 stainless steel.
  • the invention controls the upper limit of the content of Si, P and S. If the content of Si in the deposited metal is too high, the low-temperature performance will be deteriorated. The segregation of P and S at the grain boundary will lead to liquefaction cracks and reheat cracks. S will also form MnS with Mn, reducing the low temperature performance. Impact toughness.
  • the present invention requires Si ⁇ 0.2%, P ⁇ 0.012%, S ⁇ 0.01%, so as to reduce the adverse effects of elements on the deposited metal.
  • the present invention considers the technological characteristics of manual arc welding, submerged arc welding, argon arc welding and other welding methods
  • the determined composition range can ensure that the austenite stability, austenite stacking fault energy and alloying effect contained in the austenite of the deposited metal can achieve the expected effect of the present invention.
  • no more than 0.6% of Cu, no more than 0.6% of Mo, and no more than 0.05% of N can be added.
  • the addition of Cu is also beneficial to improve the corrosion resistance of the material to a certain extent.
  • not more than 0.3% of V, not more than 0.1% of Al, and not more than 0.1% of Ti is beneficial to improve the strength of the deposited metal, and can also improve the material in the form of fine dispersed second phase particles. Service performance in hydrogen containing environment.
  • the high manganese steel wire rod used for welding has a diameter of 5.5-6.5mm, and the reduction of area in the tensile test is greater than or equal to 50%.
  • the -269°C impact energy of the deposited metal formed by the high manganese steel wire rod for welding is ⁇ 60J.
  • the rolling process of high manganese steel wire rod for welding of the present invention comprises the following steps:
  • the rolling start temperature is 1030-1130°C
  • the inlet temperature of the finishing rolling unit is 980-1040°C
  • the temperature of the entering and reducing sizing unit is 900-960°C
  • the maximum reduction rate of the rolled piece is ⁇ 35%
  • the target diameter is 5.5-6.5 mm
  • the furnace temperature in the preheating section is 550-750°C
  • the furnace temperature in the heating section I is 800-1100°C
  • the furnace temperature in the heating section II is 1050-1180°C
  • the furnace temperature in the soaking section is 1080-1170°C .
  • the alloy content of the steel wire rod of the invention is high, and the thermal conductivity of the material below 750°C is less than half of that of the low alloy steel, so preheating is required to avoid thermal stress from causing the billet to crack.
  • the use of two-stage heating zone control during the heating process can further avoid thermal cracks.
  • sufficiently high heating and soaking temperatures are required.
  • the solidus temperature of the billet is 1215-1290°C, which is far lower than that of common low-alloy steel billets, so the heating and soaking temperatures cannot be too high.
  • the temperature of the highest heating point is controlled to be 35° C. or lower than the solidus temperature.
  • High-pressure water descaling is carried out after the billet is released from the furnace to ensure sufficient descaling water pressure to remove the iron oxide scale formed during the heating process.
  • the temperature of the rolled piece is the lowest in the reducing and sizing unit. At this time, it is necessary to ensure that the lowest point temperature is above the critical temperature of carbide precipitation, that is, above 900 ° C, to avoid carbide precipitation. Determine the maximum reduction rate of the rolled piece ⁇ 35% according to the hot processing map to avoid rolling cracks. After spinning, the rolled piece is forced to be air-cooled.
  • the cooling rate can be obtained by air cooling, which realizes on-line solid solution treatment, avoids the precipitation of coarse carbides in the austenite structure, and significantly improves the steel quality.
  • the plasticity of the wire rod, the reduction of area in the tensile test is ⁇ 50%, thereby improving the manufacturability of subsequent drawing for manufacturing welding consumables.
  • the invention makes the material have austenite structure and excellent performance by alloying C, Mn, Cr and adding a certain amount of Ni, and prepares a steel wire rod with excellent plasticity through a matching steel rolling process.
  • the steel wire rod of the invention is welded after being made into welding rods or welding wires, and the formed welding seam metal has an impact energy of more than 60J at -269°C and has excellent low-temperature toughness.
  • the Ni content is reduced by more than 50%, the nickel saving effect is remarkable, and the cost is greatly reduced.
  • the steel wire rod of the invention is particularly suitable for manufacturing high-manganese low-temperature steel matching welding materials, and building low-temperature storage and transportation containers required for liquefied ethylene, liquefied natural gas, liquid hydrogen or liquid helium.
  • Fig. 1 is the austenite structure with cellular dendrite structure of the welding deposited metal formed after the wire rod of Example 1 is made into an electrode.
  • Embodiment 1 use the square billet that section side length is 170mm, chemical composition comprises in mass percent: 0.3% C, 26.5% Mn, 4% Ni, 4% Cr, 0.08% Si, 0.012% P, 0.007% S, the balance is Fe and unavoidable impurities.
  • the furnace temperature in the preheating section is 750°C
  • the furnace temperature in the heating section I is 1100°C
  • the furnace temperature in the heating section II is 1180°C
  • the furnace temperature in the soaking section is 1170°C.
  • the high pressure water descaling pressure is 15MPa.
  • the rolling start temperature is 1130°C
  • the inlet temperature of the finish rolling unit is 1040°C
  • the temperature of the entering and reducing sizing unit is 960°C.
  • the maximum reduction rate of the rolled piece is 35%
  • the target diameter is 6.5mm.
  • the spinning temperature is 965°C, and forced air cooling after spinning.
  • the reduction of area of the wire rod tensile test is 50%.
  • the wire rod is annealed and drawn to make a 4.0mm diameter straight strip, wrapped with a special coating to make an electrode, and then welded a 16mm thick high-manganese low-temperature steel plate by manual arc welding with a line energy of 21kJ/cm.
  • the impact energy of metal at -269°C is 60J.
  • the weld deposit formed after the wire rod is made into an electrode has an austenite structure with a cellular dendrite structure, which is an important factor for its -269°C impact energy above 60J.
  • Embodiment 2 Use the square billet that section side length is 130mm, chemical composition comprises in mass percent: 0.5% C, 32.5% Mn, 5.5% Ni, 6% Cr, 0.15% Si, 0.005% P, 0.003% S, the balance is Fe and unavoidable impurities.
  • the furnace temperature in the preheating section is 550°C
  • the furnace temperature in the heating section I is 800°C
  • the furnace temperature in the heating section II is 1050°C
  • the furnace temperature in the soaking section is 1080°C.
  • the pressure of high-pressure water descaling is 19MPa.
  • the rolling start temperature is 1030°C
  • the inlet temperature of the finish rolling unit is 980°C
  • the temperature of the entering and reducing sizing unit is 900°C.
  • the maximum reduction rate of the rolled piece is 30%
  • the target diameter is 5.5mm.
  • the spinning temperature is 910°C, and forced air cooling after spinning.
  • the reduction of area in the tensile test of the wire rod is 62%.
  • the wire rod is annealed and drawn to make a 3.2mm diameter straight strip, wrapped with a special coating to make an electrode, and then welded a 20mm thick high-manganese low-temperature steel plate by manual arc welding, with a line energy of 19kJ/cm.
  • the impact energy of metal at -269°C is 67J.
  • Embodiment 3 use the square billet that section side length is 150mm, chemical composition comprises in mass percent: 0.4% C, 29% Mn, 5% Ni, 5% Cr, 0.2% Si, 0.007% P, 0.01% S, the balance is Fe and unavoidable impurities.
  • the furnace temperature in the preheating section is 630°C
  • the furnace temperature in the heating section I is 900°C
  • the furnace temperature in the heating section II is 1120°C
  • the furnace temperature in the soaking section is 1110°C.
  • the high pressure water descaling pressure is 17MPa.
  • the rolling start temperature is 1040°C
  • the inlet temperature of the finishing rolling unit is 1005°C
  • the temperature of the entering and reducing sizing unit is 920°C.
  • the maximum reduction rate of the rolled piece is 28%
  • the target diameter is 6.5mm.
  • the spinning temperature is 930°C, and forced air cooling after spinning.
  • the reduction in area of the wire rod tensile test is 58%.
  • the wire rod is annealed and drawn to make a diameter of 4.0mm.
  • the 30mm thick high-manganese low-temperature steel plate is welded by submerged arc welding.
  • the line energy is 24kJ/cm
  • the impact energy of the deposited metal at -269°C is 70J.
  • Embodiment 4 Use the square billet that section side length is 150mm, chemical composition comprises in mass percent: 0.4% C, 27% Mn, 5% Ni, 4% Cr, 0.07% Si, 0.01% P, 0.003% S, 0.6% Cu, 0.6% Mo, 0.03% V, 0.1% Al, 0.1% Ti, 0.05% N, and the balance is Fe and unavoidable impurities.
  • the furnace temperature in the preheating section is 700°C
  • the furnace temperature in the heating section I is 1020°C
  • the furnace temperature in the heating section II is 1120°C
  • the furnace temperature in the soaking section is 1110°C.
  • the high pressure water descaling pressure is 15MPa.
  • the rolling start temperature is 1030°C
  • the inlet temperature of the finishing rolling unit is 990°C
  • the temperature of the entering and reducing sizing unit is 910°C.
  • the maximum reduction rate of the rolled piece is ⁇ 35%
  • the target diameter is 6.0mm.
  • the spinning temperature is 915°C, and forced air cooling after spinning.
  • the reduction of area in the wire rod tensile test is 53%.
  • the wire rod is annealed and drawn to make a diameter of 4.0mm, wrapped with a special coating to make an electrode, and then welded a 20mm thick high-manganese low-temperature steel plate by manual arc welding with a line energy of 20kJ/cm.
  • the impact energy at -269°C is 76J.
  • the steel rolling process of comparative example 1 is consistent with the steel rolling process of the present invention, has prepared diameter 5.5mm wire rod, and chemical composition comprises: the Cr of 0.21% C, 18.3% Mn, 1.1% Ni, 5.2% by mass percentage , 0.09% Si, 0.009% P, 0.003% S, and the balance is Fe and unavoidable impurities.
  • the -269°C impact energy of the welded deposited metal formed after the wire rod is made into an electrode is 40J, which is lower than the effect of the present invention.
  • Comparative Example 2 also adopts the same steel rolling process as the present invention to prepare a wire rod with a diameter of 5.5mm, and the chemical composition includes: 0.7% of C, 31.5% of Mn, 4.3% of Ni, 6.9% of Cr, 0.10% in mass percent % Si, 0.011% P, 0.005% S, and the balance is Fe and unavoidable impurities.
  • the content of C and Cr in the composition of this example exceeds the range of the present invention, the critical temperature of carbide precipitation is 1010°C, which is higher than the spinning temperature range of the steel rolling process of the present invention, and obvious carbide precipitation occurs before spinning.
  • the reduction of area in the wire rod tensile test is 27%, which is lower than the effect of the present invention. Cause final technical effect also can not satisfy.
  • the wire rod chemical composition of comparative example 3 comprises in mass percent: 0.3% of C, 26.5% of Mn, 4% of Ni, 4% of Cr, 0.08% of Si, 0.012% of P, 0.007% of S, The balance is Fe and unavoidable impurities. What changed in the rolling process of wire rod with a diameter of 5.5mm is that after spinning, it is slowly cooled in the cover, resulting in the precipitation of coarse carbides in the structure of the wire rod, which reduces the plasticity, and the reduction of area in the tensile test is 27%. In the end, the target technical effect was not achieved.

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Abstract

The present invention relates to the technical field of metal materials, and disclosed are a high-manganese steel wire rod for welding and a steel rolling process therefor. By alloying C, Mn and Cr and in combination with a certain amount of Ni, the material has an austenite structure and excellent properties, and a steel wire rod having excellent plasticity is prepared by means of a matching steel rolling process. In the present invention, the steel wire rod is made into a welding rod or welding wire and then welded, and a weld metal formed has impact energy of more than 60 J at a temperature of -269°C and has excellent low-temperature toughness. Compared with a stainless-steel wire rod having a similar use, the content of Ni is reduced by more than 50%, a nickel-saving effect is significant, and the cost is greatly reduced. According to the present invention, the steel wire rod is particularly suitable for manufacturing a high-manganese low-temperature steel matching welding material, and constructing a low-temperature storage-transport vessel required for liquefied ethylene, liquefied natural gas, liquid hydrogen or liquid helium.

Description

一种焊接用高锰钢盘条及其轧钢工艺A kind of high manganese steel wire rod for welding and steel rolling process thereof 技术领域technical field
本发明属于金属材料技术领域，具体涉及一种焊接用高锰钢盘条及其轧钢工艺。The invention belongs to the technical field of metal materials, and in particular relates to a high manganese steel wire rod for welding and a steel rolling process thereof.
背景技术Background technique
目前我国已成为乙烯、天然气等基础原燃料最大需求国家，推动了液化乙烯、液化天然气等低温储运容器建造的快速增长。在我国实现“碳中和”过程中，氢能作为最具发展潜力的清洁能源更是深度减排的“攻坚利器”，工信部将“氢冶金”列为钢铁工业高质量发展主要目标之一，液氢低温储运容器建造将迎来增长。此外，氦气在卫星飞船发射、导弹武器工业、低温超导研究、半导体生产等方面具有重要用途，是重要的战略物资，我国近年来对氦气的需求量越来越大，推动了液氦储运容器需求的提升。At present, my country has become the country with the largest demand for basic raw materials such as ethylene and natural gas, which has promoted the rapid growth of the construction of low-temperature storage and transportation containers such as liquefied ethylene and liquefied natural gas. In the process of realizing "carbon neutrality" in my country, hydrogen energy, as the clean energy with the most development potential, is a "tough weapon" for deep emission reduction. The Ministry of Industry and Information Technology has listed "hydrogen metallurgy" as one of the main goals of the high-quality development of the iron and steel industry. The construction of liquid hydrogen cryogenic storage and transportation containers will usher in growth. In addition, helium has important uses in satellite spacecraft launch, missile weapon industry, low-temperature superconducting research, semiconductor production, etc., and is an important strategic material. Increased demand for storage and transportation containers.
传统低温容器用钢如殷瓦钢(36％Ni)、奥氏体不锈钢(10％Ni)、9％Ni钢等镍含量高，配套焊材也需要添加10％甚至更高的镍。同时，《汽车产业中长期发展规划》提出动力电池三元正极材料“高镍化”已成为提升电池能量密度的重要途径。但是，我国属于“贫镍”国家，镍金属对外依存度超过60％。因此，开发以高锰低温钢为代表的新一代节镍型低温钢，以及与之配套的节镍型焊材，具有重要意义。一是填补液化乙烯、液化天然气、液氢、液氦等储运设施经济型关键材料的国内空白，实现自主保障；二是为动力电池制造释放更多的镍资源空间，助力新能源汽车产业链发展；三是为实现“碳达峰”、“碳中和”目标作出贡献。Traditional cryogenic container steels such as invar steel (36% Ni), austenitic stainless steel (10% Ni), and 9% Ni steel have high nickel content, and matching welding consumables also need to add 10% or even higher nickel. At the same time, the "Medium and Long-term Development Plan of the Automobile Industry" proposes that "high nickelization" of ternary cathode materials for power batteries has become an important way to increase the energy density of batteries. However, my country is a "nickel-poor" country, and its external dependence on nickel metal exceeds 60%. Therefore, it is of great significance to develop a new generation of nickel-saving low-temperature steel represented by high-manganese low-temperature steel, and its matching nickel-saving welding consumables. One is to fill the domestic blank of economical key materials for storage and transportation facilities such as liquefied ethylene, liquefied natural gas, liquid hydrogen, and liquid helium, and realize independent guarantee; the other is to release more nickel resource space for power battery manufacturing and help the new energy vehicle industry chain The third is to contribute to the realization of the goals of "carbon peak" and "carbon neutrality".
常压条件下获得液化乙烯、液化天然气、液氢和液氦的温度分别为-104℃、-162℃、-253℃和-269℃，对储运容器材料的力学性能要求极高，特别是低温下的冲击韧性。目前使用温度最低能够达到-269℃且应用较多的低温钢如S30403、S31603不锈钢，制造配套焊材使用的不锈钢盘条如H06Cr21Ni10、H06Cr19Ni12Mo2的Ni含量均在10％以上。高锰低温钢作为新一代节镍型低温钢备受瞩目，但其成分体系特殊、工艺控制难度大。韩国浦项已成功开发可应用于液化天然气储运的高锰低温钢钢板及焊材产品并进入应用推广阶段，而国内总体尚处在研制阶段，与高锰低温钢配套的节镍型焊材的研发需要与钢板同步加快。The temperatures for obtaining liquefied ethylene, liquefied natural gas, liquid hydrogen, and liquid helium under normal pressure are -104°C, -162°C, -253°C, and -269°C, respectively. The mechanical properties of storage and transportation container materials are extremely high, especially Impact toughness at low temperatures. At present, the lowest temperature can reach -269°C and low-temperature steels such as S30403 and S31603 stainless steel are widely used. The Ni content of stainless steel wire rods used in the manufacture of supporting welding materials such as H06Cr21Ni10 and H06Cr19Ni12Mo2 are all above 10%. High-manganese low-temperature steel has attracted much attention as a new generation of nickel-saving low-temperature steel, but its composition system is special and the process control is difficult. South Korea’s POSCO has successfully developed high-manganese low-temperature steel plates and welding consumables that can be used in the storage and transportation of liquefied natural gas and has entered the stage of application and promotion. However, the country is still in the development stage in general, and the nickel-saving welding consumables that match high-manganese low-temperature steel The research and development of the steel plate needs to be accelerated simultaneously.
发明内容Contents of the invention
发明目的：为了克服现有技术的缺陷，本发明提供一种焊接用高锰钢盘条， 该钢盘条可作为制造高锰低温钢配套焊材的钢铁原料，钢盘条本身具有优良塑性，所形成的熔敷金属具有优良低温韧性。Purpose of the invention: In order to overcome the defects of the prior art, the present invention provides a high-manganese steel wire rod for welding, which can be used as the steel raw material for manufacturing high-manganese low-temperature steel matching welding consumables, and the steel wire rod itself has excellent plasticity, The formed deposited metal has excellent low temperature toughness.
本发明的另一目的是提供一种上述焊接用高锰钢盘条的轧钢工艺。Another object of the present invention is to provide a steel rolling process for the above-mentioned high manganese steel wire rod for welding.
技术方案：本发明所述的一种焊接用高锰钢盘条，其特征在于，成分以质量％计含有C：0.3～0.5％、Mn：26.5～32.5％、Ni：4～5.5％、Cr：4～6％、Si≤0.2％、P≤0.012％、S≤0.008％，余量包含Fe和不可避免的杂质。Technical solution: A high manganese steel wire rod for welding according to the present invention is characterized in that the composition contains C: 0.3-0.5%, Mn: 26.5-32.5%, Ni: 4-5.5%, Cr : 4 to 6%, Si≤0.2%, P≤0.012%, S≤0.008%, and the balance contains Fe and unavoidable impurities.
进一步的，该焊接用高锰钢盘条还含有Cu≤0.6％、Mo≤0.6％、V≤0.3％、Al≤0.1％、Ti≤0.1％、N≤0.05％当中的一种或两种以上元素代替一部分所述Fe。Further, the high manganese steel wire rod for welding also contains one or more of Cu≤0.6%, Mo≤0.6%, V≤0.3%, Al≤0.1%, Ti≤0.1%, N≤0.05% element instead of a part of the Fe.
本发明的化学成分设计原理如下：The chemical composition design principle of the present invention is as follows:
奥氏体组织具有优良的强度、塑性、韧性匹配和更低的使用温度。添加高含量的Ni虽然能够获得奥氏体组织，如304奥氏体不锈钢等，但经济型差，因此需要综合使用多种能够稳定奥氏体的合金元素。C、Mn、Ni都是奥氏体形成元素，并能够降低马氏体转变温度，有利于提高奥氏体稳定性。Cr虽然是铁素体形成元素，但能够降低马氏体转变温度，因此也有利于提高奥氏体稳定性。奥氏体的稳定性通过稳定性系数进行衡量：Austenitic structure has excellent strength, plasticity, toughness matching and lower service temperature. Although adding a high content of Ni can obtain an austenitic structure, such as 304 austenitic stainless steel, etc., the economy is poor, so it is necessary to use a variety of alloying elements that can stabilize austenite. C, Mn, and Ni are all austenite forming elements, and can reduce the martensite transformation temperature, which is beneficial to improve the stability of austenite. Although Cr is a ferrite forming element, it can lower the martensitic transformation temperature, so it is also beneficial to improve the stability of austenite. The stability of austenite is measured by the stability factor:
奥氏体稳定性系数＝35C+0.5Mn+Ni-0.0833(Cr-20) 2-12。本发明控制C、Mn、Ni、Cr的添加量下限，使奥氏体稳定性系数≥-5.6，确保足够的奥氏体稳定性。 Austenite stability factor = 35C+0.5Mn+Ni-0.0833(Cr-20) 2 -12. The invention controls the lower limit of the addition amount of C, Mn, Ni and Cr to make the austenite stability coefficient ≥-5.6 and ensure sufficient austenite stability.
通过上述四种元素含量存在于奥氏体稳定性系数表达式中的形式可知，C具有最强烈的奥氏体稳定化效果。本发明考虑到低温钢在很多服役条件下并不对耐蚀性有特殊要求，因此并未像不锈钢合金设计那样控制很低的C含量，而是采用了0.3％以上的中高C的设计以提高奥氏体稳定性。但是，C含量提高导致碳化物析出临界温度提高，使得盘条热轧与热处理工艺窗口变窄，而且也会增加焊接过程中碳化物析出倾向，因此需要控制含量上限。在本发明将C含量控制在0.5％以内可以使得碳化物析出临界温度低于900℃。It can be seen from the form that the content of the above four elements exists in the expression of the austenite stability coefficient, C has the strongest austenite stabilizing effect. The present invention considers that low-temperature steel does not have special requirements for corrosion resistance under many service conditions, so it does not control the very low C content like the design of stainless steel alloys, but adopts the design of medium and high C above 0.3% to improve the corrosion resistance. body stability. However, the increase of C content leads to the increase of the critical temperature of carbide precipitation, which narrows the process window of hot rolling and heat treatment of wire rod, and also increases the tendency of carbide precipitation during welding, so the upper limit of the content needs to be controlled. In the present invention, controlling the C content within 0.5% can make the carbide precipitation critical temperature lower than 900°C.
Ni具有较高的奥氏体稳定化效果，而且Ni是非碳化物形成元素，添加一定含量的Ni有利于获得更优良的低温性能。304不锈钢等材料的成分中添加了大量的Ni元素，虽然也具有一定的低温韧性，但其含量设计的出发点是控制组织类型并获得高耐蚀性。当材料作为低温环境下使用的结构材料时，特别是在-104℃至-269℃的极低温环境下作为液化乙烯、液化天然气、液氢和液氦储运容器的结构材料时，并不对材料的耐蚀性有要求。因此，本发明在成分设计中降低Ni含量，将Ni含量控制在4-5.5％范围内。Ni含量降低后，通过Mn和Cr元素的含 量确保足够的奥氏体稳定性。Ni has a high austenite stabilization effect, and Ni is a non-carbide forming element. Adding a certain amount of Ni is beneficial to obtain better low temperature performance. A large amount of Ni element is added to the composition of 304 stainless steel and other materials. Although it also has certain low-temperature toughness, the starting point of its content design is to control the structure type and obtain high corrosion resistance. When the material is used as a structural material in a low temperature environment, especially when it is used as a structural material for liquefied ethylene, liquefied natural gas, liquid hydrogen and liquid helium storage and transportation containers in an extremely low temperature environment from -104°C to -269°C, it is not suitable for the material Corrosion resistance is required. Therefore, the present invention reduces the Ni content in the composition design and controls the Ni content within the range of 4-5.5%. Sufficient austenite stability is ensured by the content of the elements Mn and Cr after the reduced Ni content.
Mn提高奥氏体稳定性的效果是Ni的一半，这一点从稳定性系数表达式中不同元素的系数差异可知。因此，降低Ni含量需要添加更多的Mn，以保证足够的奥氏体稳定性。Mn作为合金，虽然廉价，但过多的Mn合金量导致工业化冶炼难度增大、轧制工艺窗口变窄，此外还会增加焊接烟尘的Mn含量。本发明确定Mn的添加量的另一个重要依据是控制奥氏体层错能。当奥氏体层错能低于16mJ/m 2，形变时主要发生马氏体相变，塑韧性低；当奥氏体层错能高于60mJ/m 2，形变时主要发生位错滑移，强度低；当奥氏体层错能介于16-60mJ/m 2，形变时主要发生孪晶，性能匹配最佳。C和Mn均提高奥氏体层错能。本发明在C含量基础上进一步确定Mn含量为26.5-32.5％，将20℃至-269℃温度范围内的奥氏体层错能控制在17-46mJ/m 2，从而获得最佳的熔敷金属力学性能。 The effect of Mn on improving the stability of austenite is half that of Ni, which can be seen from the coefficient difference of different elements in the stability coefficient expression. Therefore, reducing the Ni content requires adding more Mn to ensure sufficient austenite stability. As an alloy, Mn is cheap, but too much Mn alloy content will increase the difficulty of industrial smelting, narrow the rolling process window, and increase the Mn content of welding fumes. Another important basis for determining the addition amount of Mn in the present invention is to control the stacking fault energy of austenite. When the austenite fault energy is lower than 16mJ/m 2 , martensitic transformation mainly occurs during deformation, and the plastic toughness is low; when the austenite fault energy is higher than 60mJ/m 2 , dislocation slip mainly occurs during deformation , low strength; when the austenite stacking fault energy is between 16-60mJ/m 2 , twins mainly occur during deformation, and the performance matching is the best. Both C and Mn increase the stacking fault energy of austenite. The present invention further determines the Mn content to be 26.5-32.5% on the basis of the C content, and controls the stacking fault energy of the austenite within the temperature range of 20°C to -269°C to 17-46mJ/ m2 , thereby obtaining the best cladding Metal mechanical properties.
当Cr元素含量在20％以内时，随着含量提高，奥氏体稳定性提高。因此，添加一定量的Cr元素也有利于降低Ni的需要量。但随着Cr含量的提高，单位含量Cr元素提高奥氏体稳定性的效果减弱。此外，Cr元素容易形成碳化物，过高的Cr含量提高了碳化物析出临界温度和碳化物析出时体积分数，不利于熔敷金属低温冲击韧性的提高。结合奥氏体稳定性、奥氏体层错能等考量因素，本发明将Cr含量控制在4-6％，远低于304不锈钢中的Cr含量。When the content of Cr element is within 20%, the stability of austenite increases as the content increases. Therefore, adding a certain amount of Cr element is also beneficial to reduce the requirement of Ni. However, with the increase of Cr content, the effect of unit content of Cr element on improving the stability of austenite is weakened. In addition, the Cr element is easy to form carbides. Excessively high Cr content increases the critical temperature of carbide precipitation and the volume fraction of carbide precipitation, which is not conducive to the improvement of the low-temperature impact toughness of the deposited metal. In consideration of factors such as austenite stability and austenite stacking fault energy, the present invention controls the Cr content to 4-6%, which is far lower than the Cr content in 304 stainless steel.
本发明控制Si、P与S的含量上限，熔敷金属中Si含量过高恶化低温性能，P和S在晶界偏聚会导致液化裂纹与再热裂纹，S还会与Mn形成MnS，降低低温冲击韧性。本发明要求Si≤0.2％，P≤0.012％，S≤0.01％，以降低元素对熔敷金属的不利影响。The invention controls the upper limit of the content of Si, P and S. If the content of Si in the deposited metal is too high, the low-temperature performance will be deteriorated. The segregation of P and S at the grain boundary will lead to liquefaction cracks and reheat cracks. S will also form MnS with Mn, reducing the low temperature performance. Impact toughness. The present invention requires Si≤0.2%, P≤0.012%, S≤0.01%, so as to reduce the adverse effects of elements on the deposited metal.
需要指出的是，钢盘条制成的焊材用于焊接时形成熔敷金属后合金含量将会发生一定程度损失，本发明考虑手工电弧焊、埋弧焊、氩弧焊等焊接方式工艺特点后所确定的成分范围能够保证熔敷金属的奥氏体稳定性、奥氏体层错能及奥氏体所含合金作用达到本发明预期效果。为了进一步提高盘条制造工艺性及熔敷金属性能，可以添加不高于0.6％的Cu、不高于0.6％的Mo、不高于0.05％的N。Cu的添加也有利于一定程度提高材料的耐蚀性。此外，添加不高于0.3％的V、不高于0.1％的Al、不高于0.1％的Ti有利于提高熔敷金属的强度，也能够通过形成细小弥散第二相粒子的形式提高材料在含氢环境中的服役性能。It should be pointed out that the alloy content will be lost to a certain extent after the welding consumables made of steel wire rod are used for welding to form deposited metal. The present invention considers the technological characteristics of manual arc welding, submerged arc welding, argon arc welding and other welding methods The determined composition range can ensure that the austenite stability, austenite stacking fault energy and alloying effect contained in the austenite of the deposited metal can achieve the expected effect of the present invention. In order to further improve the manufacturability of the wire rod and the performance of the deposited metal, no more than 0.6% of Cu, no more than 0.6% of Mo, and no more than 0.05% of N can be added. The addition of Cu is also beneficial to improve the corrosion resistance of the material to a certain extent. In addition, the addition of not more than 0.3% of V, not more than 0.1% of Al, and not more than 0.1% of Ti is beneficial to improve the strength of the deposited metal, and can also improve the material in the form of fine dispersed second phase particles. Service performance in hydrogen containing environment.
具体的，该焊接用高锰钢盘条直径为5.5～6.5mm，拉伸试验断面收缩率≥50％。Specifically, the high manganese steel wire rod used for welding has a diameter of 5.5-6.5mm, and the reduction of area in the tensile test is greater than or equal to 50%.
该焊接用高锰钢盘条形成的熔敷金属的-269℃冲击功≥60J。The -269°C impact energy of the deposited metal formed by the high manganese steel wire rod for welding is ≥60J.
本发明所述的焊接用高锰钢盘条的轧钢工艺，包括如下步骤：The rolling process of high manganese steel wire rod for welding of the present invention comprises the following steps:
(1)将成分符合要求断面边长为130-170mm的方坯送入加热炉加热，其中，所述方坯的固相线温度为1215-1290℃，加热最高点温度控制在低于固相线温度35℃或更低，且需要预热；(1) Send a square billet whose composition meets the requirements and whose cross-sectional side length is 130-170mm into a heating furnace for heating, wherein the solidus temperature of the billet is 1215-1290°C, and the temperature at the highest heating point is controlled below the solidus temperature The line temperature is 35°C or lower, and preheating is required;
(2)坯料出炉后进行高压水除鳞，除鳞压力≥15MPa；(2) Descaling with high-pressure water after the billet is out of the furnace, the descaling pressure is ≥ 15MPa;
(3)轧制的开轧温度1030-1130℃，精轧机组入口温度980-1040℃，入减定径机组温度900-960℃；轧件最大压下率≤35％，目标直径5.5-6.5mm，吐丝温度910-965℃；(3) The rolling start temperature is 1030-1130°C, the inlet temperature of the finishing rolling unit is 980-1040°C, and the temperature of the entering and reducing sizing unit is 900-960°C; the maximum reduction rate of the rolled piece is ≤35%, and the target diameter is 5.5-6.5 mm, spinning temperature 910-965°C;
(4)吐丝后强制风冷。(4) Forced air cooling after spinning.
具体的，所述步骤(1)中，预热段炉温550-750℃，加热I段炉温800～1100℃，加热II段炉温1050-1180℃，均热段炉温1080-1170℃。Specifically, in the step (1), the furnace temperature in the preheating section is 550-750°C, the furnace temperature in the heating section I is 800-1100°C, the furnace temperature in the heating section II is 1050-1180°C, and the furnace temperature in the soaking section is 1080-1170°C .
本发明的轧钢工艺设计原理如下：Steel rolling process design principle of the present invention is as follows:
本发明钢盘条的合金含量高，在750℃以下材料的导热系数不到低合金钢的一半，因此需要对进行预热，以避免热应力导致坯料开裂。在加热升温过程中采用两阶段加热区控制，也能够进一步避免热裂纹。为了使碳化物回溶及奥氏体均匀化，需要足够高的加热及均热温度。但是，坯料的固相线温度为1215-1290℃，远低于普通低合金钢坯料的固相线温度，因此加热和均热温度不能过高。本发明将加热最高点温度控制在低于固相线温度35℃或者更低。坯料出炉后进行高压水除鳞，保证足够的除鳞水压力，以去除加热过程中形成的氧化铁皮。在开轧至吐丝的整个轧制过程中，轧件在减定径机组温度最低，此时需要保证最低点温度在碳化物析出临界温度以上，即900℃以上，以避免碳化物析出。根据热加工图确定轧件最大压下率≤35％，避免出现轧制裂纹。吐丝后对轧件进行强制风冷，因为轧件直径小，风冷即可获得足够大的冷却速率，实现了在线固溶处理，避免奥氏体组织中的粗大碳化物析出，显著提高钢盘条的塑性，拉伸试验断面收缩率≥50％，从而提高了在后续用于制造焊材而进行拉拔时的工艺性。The alloy content of the steel wire rod of the invention is high, and the thermal conductivity of the material below 750°C is less than half of that of the low alloy steel, so preheating is required to avoid thermal stress from causing the billet to crack. The use of two-stage heating zone control during the heating process can further avoid thermal cracks. In order to redissolve carbides and homogenize austenite, sufficiently high heating and soaking temperatures are required. However, the solidus temperature of the billet is 1215-1290°C, which is far lower than that of common low-alloy steel billets, so the heating and soaking temperatures cannot be too high. In the present invention, the temperature of the highest heating point is controlled to be 35° C. or lower than the solidus temperature. High-pressure water descaling is carried out after the billet is released from the furnace to ensure sufficient descaling water pressure to remove the iron oxide scale formed during the heating process. During the entire rolling process from rolling to spinning, the temperature of the rolled piece is the lowest in the reducing and sizing unit. At this time, it is necessary to ensure that the lowest point temperature is above the critical temperature of carbide precipitation, that is, above 900 ° C, to avoid carbide precipitation. Determine the maximum reduction rate of the rolled piece ≤ 35% according to the hot processing map to avoid rolling cracks. After spinning, the rolled piece is forced to be air-cooled. Because the diameter of the rolled piece is small, the cooling rate can be obtained by air cooling, which realizes on-line solid solution treatment, avoids the precipitation of coarse carbides in the austenite structure, and significantly improves the steel quality. The plasticity of the wire rod, the reduction of area in the tensile test is ≥ 50%, thereby improving the manufacturability of subsequent drawing for manufacturing welding consumables.
有益效果：本发明通过C、Mn、Cr合金化并配合一定量的Ni，使材料具有奥氏体组织以及优良性能，并通过配套的轧钢工艺制备出具有优良塑性的钢盘条。本发明钢盘条制成焊条或焊丝后进行焊接，所形成的焊缝金属-269℃冲击功在60J以上，具有优良的低温韧性。与类似用途的不锈钢盘条相比，Ni含量减少50％以上，节镍效果显著，成本大幅降低。本发明钢盘条特别合适用于制造高锰低温钢配套焊材，建造液化乙烯、液化天然气、液氢或液氦所需的低温储运容器。Beneficial effects: the invention makes the material have austenite structure and excellent performance by alloying C, Mn, Cr and adding a certain amount of Ni, and prepares a steel wire rod with excellent plasticity through a matching steel rolling process. The steel wire rod of the invention is welded after being made into welding rods or welding wires, and the formed welding seam metal has an impact energy of more than 60J at -269°C and has excellent low-temperature toughness. Compared with stainless steel wire rods of similar purposes, the Ni content is reduced by more than 50%, the nickel saving effect is remarkable, and the cost is greatly reduced. The steel wire rod of the invention is particularly suitable for manufacturing high-manganese low-temperature steel matching welding materials, and building low-temperature storage and transportation containers required for liquefied ethylene, liquefied natural gas, liquid hydrogen or liquid helium.
附图说明Description of drawings
图1是实施例1盘条制成焊条后形成的焊接熔敷金属的具有胞状树枝晶结构的奥氏体组织。Fig. 1 is the austenite structure with cellular dendrite structure of the welding deposited metal formed after the wire rod of Example 1 is made into an electrode.
具体实施方式Detailed ways
以下提供几组具体的实施例对本发明作进一步说明。Several groups of specific examples are provided below to further illustrate the present invention.
需要特别说明的是，下述实施例是从众多生产和试验数据中提取的几组具有代表性的案例，目的是为了证明严格按照本发明的技术方案生产的钢盘条，均能满足制造高锰低温钢配套焊材的技术要求，并能获得良好的-269℃低温冲击韧性。It should be noted that the following examples are several groups of representative cases extracted from numerous production and test data, and the purpose is to prove that the steel wire rod produced strictly according to the technical scheme of the present invention can meet the requirements of high manufacturing requirements. Manganese low temperature steel matching welding consumables technical requirements, and can obtain good -269 ℃ low temperature impact toughness.
实施例1：使用断面边长为170mm的方坯，化学组分以质量百分数计包括：0.3％的C、26.5％的Mn、4％的Ni、4％的Cr、0.08％的Si、0.012％的P、0.007％的S，余量为Fe和不可避免的杂质。预热段炉温750℃，加热I段炉温1100℃，加热II段炉温1180℃，均热段炉温1170℃。坯料出炉后高压水除鳞压力15MPa。开轧温度1130℃、精轧机组入口温度1040℃、入减定径机组温度960℃。轧件最大压下率35％，目标直径6.5mm。吐丝温度965℃，吐丝后强制风冷。盘条拉伸试验断面收缩率50％。盘条经退火拉拔制成4.0mm直径直条，包裹特药皮制成焊条后通过手工电弧焊焊接方式对16mm厚高锰低温钢钢板进行焊接，线能量21kJ/cm，所形成的熔敷金属的-269℃冲击功为60J。如图1所示，盘条制成焊条后形成的焊接熔敷金属具有胞状树枝晶结构的奥氏体组织，该组织是其-269℃冲击功在60J以上的重要因素。Embodiment 1: use the square billet that section side length is 170mm, chemical composition comprises in mass percent: 0.3% C, 26.5% Mn, 4% Ni, 4% Cr, 0.08% Si, 0.012% P, 0.007% S, the balance is Fe and unavoidable impurities. The furnace temperature in the preheating section is 750°C, the furnace temperature in the heating section I is 1100°C, the furnace temperature in the heating section II is 1180°C, and the furnace temperature in the soaking section is 1170°C. After the billet is out of the furnace, the high pressure water descaling pressure is 15MPa. The rolling start temperature is 1130°C, the inlet temperature of the finish rolling unit is 1040°C, and the temperature of the entering and reducing sizing unit is 960°C. The maximum reduction rate of the rolled piece is 35%, and the target diameter is 6.5mm. The spinning temperature is 965°C, and forced air cooling after spinning. The reduction of area of the wire rod tensile test is 50%. The wire rod is annealed and drawn to make a 4.0mm diameter straight strip, wrapped with a special coating to make an electrode, and then welded a 16mm thick high-manganese low-temperature steel plate by manual arc welding with a line energy of 21kJ/cm. The impact energy of metal at -269°C is 60J. As shown in Figure 1, the weld deposit formed after the wire rod is made into an electrode has an austenite structure with a cellular dendrite structure, which is an important factor for its -269°C impact energy above 60J.
实施例2：使用断面边长为130mm的方坯，化学组分以质量百分数计包括：0.5％的C、32.5％的Mn、5.5％的Ni、6％的Cr、0.15％的Si、0.005％的P、0.003％的S，余量为Fe和不可避免的杂质。预热段炉温550℃，加热I段炉温800℃，加热II段炉温1050℃，均热段炉温1080℃。坯料出炉后高压水除鳞压力19MPa。开轧温度1030℃、精轧机组入口温度980℃、入减定径机组温度900℃。轧件最大压下率30％，目标直径5.5mm。吐丝温度910℃，吐丝后强制风冷。盘条拉伸试验断面收缩率62％。盘条经退火拉拔制成3.2mm直径直条，包裹特药皮制成焊条后通过手工电弧焊焊接方式对20mm厚高锰低温钢钢板进行焊接，线能量19kJ/cm，所形成的熔敷金属的-269℃冲击功为67J。Embodiment 2: Use the square billet that section side length is 130mm, chemical composition comprises in mass percent: 0.5% C, 32.5% Mn, 5.5% Ni, 6% Cr, 0.15% Si, 0.005% P, 0.003% S, the balance is Fe and unavoidable impurities. The furnace temperature in the preheating section is 550°C, the furnace temperature in the heating section I is 800°C, the furnace temperature in the heating section II is 1050°C, and the furnace temperature in the soaking section is 1080°C. After the blank is out of the furnace, the pressure of high-pressure water descaling is 19MPa. The rolling start temperature is 1030°C, the inlet temperature of the finish rolling unit is 980°C, and the temperature of the entering and reducing sizing unit is 900°C. The maximum reduction rate of the rolled piece is 30%, and the target diameter is 5.5mm. The spinning temperature is 910°C, and forced air cooling after spinning. The reduction of area in the tensile test of the wire rod is 62%. The wire rod is annealed and drawn to make a 3.2mm diameter straight strip, wrapped with a special coating to make an electrode, and then welded a 20mm thick high-manganese low-temperature steel plate by manual arc welding, with a line energy of 19kJ/cm. The impact energy of metal at -269°C is 67J.
实施例3：使用断面边长为150mm的方坯，化学组分以质量百分数计包括：0.4％的C、29％的Mn、5％的Ni、5％的Cr、0.2％的Si、0.007％的P、0.01％的S，余量为Fe和不可避免的杂质。预热段炉温630℃，加热I段炉温900，加热II 段炉温1120℃，均热段炉温1110℃。坯料出炉后高压水除鳞压力17MPa。开轧温度1040℃、精轧机组入口温度1005℃、入减定径机组温度920℃。轧件最大压下率28％，目标直径6.5mm。吐丝温度930℃，吐丝后强制风冷。盘条拉伸试验断面收缩率58％。盘条经退火拉拔制成4.0mm直径，通过埋弧焊焊接方式对30mm厚高锰低温钢钢板进行焊接，线能量24kJ/cm，所形成的熔敷金属的-269℃冲击功为70J。Embodiment 3: use the square billet that section side length is 150mm, chemical composition comprises in mass percent: 0.4% C, 29% Mn, 5% Ni, 5% Cr, 0.2% Si, 0.007% P, 0.01% S, the balance is Fe and unavoidable impurities. The furnace temperature in the preheating section is 630°C, the furnace temperature in the heating section I is 900°C, the furnace temperature in the heating section II is 1120°C, and the furnace temperature in the soaking section is 1110°C. After the blank is out of the furnace, the high pressure water descaling pressure is 17MPa. The rolling start temperature is 1040°C, the inlet temperature of the finishing rolling unit is 1005°C, and the temperature of the entering and reducing sizing unit is 920°C. The maximum reduction rate of the rolled piece is 28%, and the target diameter is 6.5mm. The spinning temperature is 930°C, and forced air cooling after spinning. The reduction in area of the wire rod tensile test is 58%. The wire rod is annealed and drawn to make a diameter of 4.0mm. The 30mm thick high-manganese low-temperature steel plate is welded by submerged arc welding. The line energy is 24kJ/cm, and the impact energy of the deposited metal at -269°C is 70J.
实施例4：使用断面边长为150mm的方坯，化学组分以质量百分数计包括：0.4％的C、27％的Mn、5％的Ni、4％的Cr、0.07％的Si、0.01％的P、0.003％的S，0.6％的Cu、0.6％的Mo、0.03％的V、0.1％的Al、0.1％的Ti、0.05％的N，余量为Fe和不可避免的杂质。预热段炉温700℃，加热I段炉温1020，加热II段炉温1120℃，均热段炉温1110℃。坯料出炉后高压水除鳞压力15MPa。开轧温度1030℃、精轧机组入口温度990℃、入减定径机组温度910℃。轧件最大压下率≤35％，目标直径6.0mm。吐丝温度915℃，吐丝后强制风冷。盘条拉伸试验断面收缩率53％。盘条经退火拉拔制成4.0mm直径，包裹特药皮制成焊条后通过手工电弧焊焊接方式对20mm厚高锰低温钢钢板进行焊接，线能量20kJ/cm，所形成的熔敷金属的-269℃冲击功为76J。Embodiment 4: Use the square billet that section side length is 150mm, chemical composition comprises in mass percent: 0.4% C, 27% Mn, 5% Ni, 4% Cr, 0.07% Si, 0.01% P, 0.003% S, 0.6% Cu, 0.6% Mo, 0.03% V, 0.1% Al, 0.1% Ti, 0.05% N, and the balance is Fe and unavoidable impurities. The furnace temperature in the preheating section is 700°C, the furnace temperature in the heating section I is 1020°C, the furnace temperature in the heating section II is 1120°C, and the furnace temperature in the soaking section is 1110°C. After the billet is out of the furnace, the high pressure water descaling pressure is 15MPa. The rolling start temperature is 1030°C, the inlet temperature of the finishing rolling unit is 990°C, and the temperature of the entering and reducing sizing unit is 910°C. The maximum reduction rate of the rolled piece is ≤35%, and the target diameter is 6.0mm. The spinning temperature is 915°C, and forced air cooling after spinning. The reduction of area in the wire rod tensile test is 53%. The wire rod is annealed and drawn to make a diameter of 4.0mm, wrapped with a special coating to make an electrode, and then welded a 20mm thick high-manganese low-temperature steel plate by manual arc welding with a line energy of 20kJ/cm. The impact energy at -269°C is 76J.
在研发阶段也产生了一些未能达到目标技术效果的试验数据，下面提供几组作为对比例，以对本发明进一步理解。In the research and development stage, some experimental data that failed to achieve the target technical effect were also produced. Several groups are provided below as comparative examples to further understand the present invention.
对比例1的轧钢工艺与本发明的轧钢工艺一致，制备了直径5.5mm盘条，化学组分以质量百分数计包括：0.21％的C、18.3％的Mn、1.1％的Ni、5.2％的Cr、0.09％的Si、0.009％的P、0.003％的S，余量为Fe和不可避免的杂质。盘条制成焊条后形成的焊接熔敷金属的-269℃冲击功为40J，低于本发明效果。经分析，该对比例的成分中，C、Mn和Ni含量低于本发明范围，稳定性系数＝-12.6、-269℃层错能为2.9mJ/m 2，稳定性和层错能均低于本发明范围，这是其未满足目标技术效果的主要原因。 The steel rolling process of comparative example 1 is consistent with the steel rolling process of the present invention, has prepared diameter 5.5mm wire rod, and chemical composition comprises: the Cr of 0.21% C, 18.3% Mn, 1.1% Ni, 5.2% by mass percentage , 0.09% Si, 0.009% P, 0.003% S, and the balance is Fe and unavoidable impurities. The -269°C impact energy of the welded deposited metal formed after the wire rod is made into an electrode is 40J, which is lower than the effect of the present invention. After analysis, the content of C, Mn and Ni in the composition of this comparative example is lower than the range of the present invention, the stability coefficient = -12.6, the stacking fault energy at -269°C is 2.9mJ/m 2 , and both the stability and the stacking fault energy are low In the scope of the present invention, this is the main reason why it does not meet the target technical effect.
对比例2同样采用与本发明相同的轧钢工艺，制备直径5.5mm盘条，化学组分以质量百分数计包括：0.7％的C、31.5％的Mn、4.3％的Ni、6.9％的Cr、0.10％的Si、0.011％的P、0.005％的S，余量为Fe和不可避免的杂质。经分析，该实施例成分中C和Cr含量超出本发明范围，碳化物析出临界温度为1010℃，高于本发明轧钢工艺的吐丝温度范围，吐丝之前就发生了明显的碳化物析出。盘条拉伸试验断面收缩率为27％，低于本发明效果。导致最终的技术效果也不能满足。Comparative Example 2 also adopts the same steel rolling process as the present invention to prepare a wire rod with a diameter of 5.5mm, and the chemical composition includes: 0.7% of C, 31.5% of Mn, 4.3% of Ni, 6.9% of Cr, 0.10% in mass percent % Si, 0.011% P, 0.005% S, and the balance is Fe and unavoidable impurities. After analysis, the content of C and Cr in the composition of this example exceeds the range of the present invention, the critical temperature of carbide precipitation is 1010°C, which is higher than the spinning temperature range of the steel rolling process of the present invention, and obvious carbide precipitation occurs before spinning. The reduction of area in the wire rod tensile test is 27%, which is lower than the effect of the present invention. Cause final technical effect also can not satisfy.
对比例3的盘条化学组分以质量百分数计包括：0.3％的C、26.5％的Mn、4％的Ni、4％的Cr、0.08％的Si、0.012％的P、0.007％的S，余量为Fe和不可避免的杂质。在直径5.5mm盘条的轧钢工艺中发生变化的是，吐丝后入罩盖缓冷，造成盘条组织中析出了粗大碳化物，降低了塑性，拉伸试验断面收缩率27％，显然其最终也未能达到目标技术效果。The wire rod chemical composition of comparative example 3 comprises in mass percent: 0.3% of C, 26.5% of Mn, 4% of Ni, 4% of Cr, 0.08% of Si, 0.012% of P, 0.007% of S, The balance is Fe and unavoidable impurities. What changed in the rolling process of wire rod with a diameter of 5.5mm is that after spinning, it is slowly cooled in the cover, resulting in the precipitation of coarse carbides in the structure of the wire rod, which reduces the plasticity, and the reduction of area in the tensile test is 27%. In the end, the target technical effect was not achieved.

Claims (9)

  1. 一种焊接用高锰钢盘条，其特征在于，成分以质量％计含有C：0.3～0.5％、Mn：26.5～32.5％、Ni：4～5.5％、Cr：4～6％、Si≤0.2％、P≤0.012％、S≤0.008％，余量包含Fe和不可避免的杂质。A high manganese steel wire rod for welding, characterized in that the composition contains C: 0.3-0.5%, Mn: 26.5-32.5%, Ni: 4-5.5%, Cr: 4-6%, Si≤ 0.2%, P≤0.012%, S≤0.008%, and the balance contains Fe and unavoidable impurities.
  2. 根据权利要求1所述的焊接用高锰钢盘条，其特征在于，还含有Cu≤0.6％、Mo≤0.6％、V≤0.3％、Al≤0.1％、Ti≤0.1％、N≤0.05％当中的一种或两种以上元素代替一部分所述Fe。The high manganese steel wire rod for welding according to claim 1, characterized in that it also contains Cu≤0.6%, Mo≤0.6%, V≤0.3%, Al≤0.1%, Ti≤0.1%, N≤0.05% Among them, one or more than two elements replace a part of the Fe.
  3. 根据权利要求1所述的焊接用高锰钢盘条，其特征在于，金相组织包括奥氏体组织，且奥氏体稳定性系数≥-5.6；其中，The high manganese steel wire rod for welding according to claim 1, wherein the metallographic structure includes austenite structure, and the austenite stability coefficient is ≥-5.6; wherein,
    奥氏体稳定性系数＝35C+0.5Mn+Ni-0.0833(Cr-20) 2-12。 Austenite stability factor = 35C+0.5Mn+Ni-0.0833(Cr-20) 2 -12.
  4. 根据权利要求3所述的焊接用高锰钢盘条，其特征在于，20℃至-269℃温度范围内的奥氏体层错能为17-46mJ/m 2。 The high manganese steel wire rod for welding according to claim 3, characterized in that the austenite stacking fault energy in the temperature range from 20°C to -269°C is 17-46mJ/m 2 .
  5. 根据权利要求1所述的焊接用高锰钢盘条，其特征在于，盘条直径为5.5～6.5mm。The high manganese steel wire rod for welding according to claim 1, characterized in that the diameter of the wire rod is 5.5-6.5mm.
  6. 根据权利要求5所述的焊接用高锰钢盘条，其特征在于，拉伸试验断面收缩率≥50％。The high manganese steel wire rod for welding according to claim 5, characterized in that the reduction of area in the tensile test is more than or equal to 50%.
  7. 根据权利要求1所述的焊接用高锰钢盘条，其特征在于，形成的熔敷金属的-269℃冲击功≥60J。The high manganese steel wire rod for welding according to claim 1, characterized in that the impact energy of the formed deposited metal at -269°C is ≥60J.
  8. 一种根据权利要求1所述的焊接用高锰钢盘条的轧钢工艺，其特征在于，包括如下步骤：A steel rolling process for welding high manganese steel wire rod according to claim 1, characterized in that, comprising the steps of:
    (1)将成分符合要求断面边长为130-170mm的方坯送入加热炉加热，其中，所述方坯的固相线温度为1215-1290℃，加热最高点温度控制在低于固相线温度35℃或更低，且需要预热；(1) Send a square billet whose composition meets the requirements and whose cross-sectional side length is 130-170mm into a heating furnace for heating, wherein the solidus temperature of the billet is 1215-1290°C, and the temperature at the highest heating point is controlled below the solidus temperature The line temperature is 35°C or lower, and preheating is required;
    (2)坯料出炉后进行高压水除鳞，除鳞压力≥15MPa；(2) Descaling with high-pressure water after the billet is out of the furnace, the descaling pressure is ≥ 15MPa;
    (3)轧制的开轧温度1030-1130℃，精轧机组入口温度980-1040℃，入减定径机组温度900-960℃；轧件最大压下率≤35％，目标直径5.5-6.5mm，吐丝温度910-965℃；(3) The rolling start temperature is 1030-1130°C, the inlet temperature of the finishing rolling unit is 980-1040°C, and the temperature of the entering and reducing sizing unit is 900-960°C; the maximum reduction rate of the rolled piece is ≤35%, and the target diameter is 5.5-6.5 mm, spinning temperature 910-965°C;
    (4)吐丝后强制风冷。(4) Forced air cooling after spinning.
  9. 根据权利要求8所述的焊接用高锰钢盘条的轧钢工艺，其特征在于，所述步骤(1)中，预热段炉温550-750℃，加热I段炉温800～1100℃，加热II段炉温1050-1180℃，均热段炉温1080-1170℃。The rolling process of high manganese steel wire rod for welding according to claim 8, characterized in that, in the step (1), the furnace temperature in the preheating section is 550-750°C, and the furnace temperature in the heating section I is 800-1100°C, The furnace temperature of the heating section II is 1050-1180°C, and the furnace temperature of the soaking section is 1080-1170°C.
PCT/CN2021/110537 2021-05-12 2021-08-04 High-manganese steel wire rod for welding and steel rolling process therefor WO2022236975A1 (en)

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Citations (2)

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CN107186382A (en) * 2017-06-09 2017-09-22 南京钢铁股份有限公司 A kind of high manganese ultralow temperature steel welding wire and its welding procedure
CN110724872A (en) * 2018-07-17 2020-01-24 宝钢特钢有限公司 High manganese austenitic steel with ultralow-temperature impact toughness and manufacturing method of hot rolled plate thereof

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KR102511652B1 (en) * 2018-08-23 2023-03-17 제이에프이 스틸 가부시키가이샤 Solid wire for gas metal arc welding

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107186382A (en) * 2017-06-09 2017-09-22 南京钢铁股份有限公司 A kind of high manganese ultralow temperature steel welding wire and its welding procedure
CN110724872A (en) * 2018-07-17 2020-01-24 宝钢特钢有限公司 High manganese austenitic steel with ultralow-temperature impact toughness and manufacturing method of hot rolled plate thereof

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