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CN-122003309-A - Coated electrode, welded joint and weld metal

CN122003309ACN 122003309 ACN122003309 ACN 122003309ACN-122003309-A

Abstract

Provided is a coated electrode for welding a structure in an extremely low temperature region, which can obtain a weld metal having excellent strength and a lateral expansion amount of a desired value or more. A coated electrode comprising 0.001 to 0.400 mass% Nb, 0.001 to 0.400 mass% V and 0.001 to 0.020 mass% N, wherein the content of Fe, C, cr, ni and the like relative to the total mass of the electrode is specified. The value A1 is not less than 0.120 and not more than 0.500, and the value A2 is not more than 0.10. Also ,A1＝［Nb］ W ＋［V］ W ,A2＝1.22×（［Cr］ W ＋［Mo］ W ＋0.7×［Nb］ W ）－（［Ni］ W ＋35×［C］ W ＋20×［N］ W ＋0.25×［Cu］ W ）－10.0. wherein [ element ] W is a value expressed in mass% of the content of the element in the coated electrode.

Inventors

  • ABE MAYUMI
  • SUZUKI MASAMICHI
  • SATO KOJI

Assignees

  • 株式会社神户制钢所

Dates

Publication Date
20260508
Application Date
20241210
Priority Date
20240119

Claims (6)

  1. 1. A coated electrode is characterized by comprising, relative to the total mass of the electrode Fe:30 mass% or more 55 mass% or less, 0.001 To 0.020 mass% inclusive of C, Cr is 10.0 to 30.0 mass%, Ni is 6.0 to 20.0 mass%, Nb:0.001 mass% or more 0.400 mass% or less, V is 0.001 to 0.400 mass%, and N is 0.001 mass% or more and 0.020 mass% or less, and Mo is 4.0 mass% or less, Cu is 0.50 mass% or less, Wherein the C does not contain C in carbonate, A value A1 calculated by the following formula (1) is 0.120 to 0.500, A2 is calculated by the following formula (2) and is 0.10 or less, A1 = [ Nb ] W ＋［V］ W ..formula (1) A2＝1.22×（［Cr］ W ＋［Mo］ W ＋0.7×［Nb］ W ）－（［Ni］ W ＋35×［C］ W ＋20×［N］ W ＋0.25×［Cu］ W ）－10.0 … (2) Wherein [ Nb ] W is a value in mass% of Nb content in the covered electrode, [ V ] W is a value in mass% of V content in the covered electrode, [ Cr ] W is a value in mass% of Cr content in the covered electrode, [ Mo ] W is a value in mass% of Mo content in the covered electrode, [ Ni ] W is a value in mass% of Ni content in the covered electrode, [ C ] W is a value in mass% of C content in the covered electrode, [ N ] W is a value in mass% of N content in the covered electrode, and [ Cu ] W is a value in mass% of Cu content in the covered electrode.
  2. 2. The coated electrode of claim 1 further comprising, relative to the total mass of the electrode F is 0.50 to 3.00 mass%, Ca:3.0 mass% or more and 9.0 mass% or less, Mn is 0.1 to 6.0 mass%, TiO 2 : 5.0 mass% or more 25.0 mass% or less, The SiO 2 conversion value of the metal Si and the Si compound is 3.0 mass% or more and 8.0 mass% or less, Na of 0.05 to 0.50 mass% inclusive and 0.05 Mass% or more and 1.50 mass% or less, and The ZrO 2 value of the metal Zr and Zr compound is less than 2.0 mass%, The MgO equivalent value of the metal Mg and the Mg compound is 1.0 mass% or less, P is 0.030 mass% or less, S is 0.030 mass% or less, Co is 0.30 mass% or less, W is 0.50 mass% or less, 0.50 Mass% or less of REM, 1.0 Mass% or less of Ti, Al is 0.3 mass% or less, Less than 2.0 mass percent of Al 2 O 3 , Li is 0.50 mass% or less.
  3. 3. The coated electrode of claim 1, wherein, 7.0 Mass% or more and 10.0 mass% or less of Ni, 12.0 Mass% or more and 15.0 mass% or less of Cr, The Mo is 1.0 mass% or more and 2.0 mass% or less.
  4. 4. A welded joint produced by welding a stainless steel sheet as a base material using the coated electrode according to any one of claims 1 to 3.
  5. 5. A weld metal comprising, relative to the total mass of the weld metal C:0.001 mass% or more 0.040 mass% or less, Cr is 14.0 to 22.0 mass%, Ni:7.0 mass% or more and 18.0 mass% or less, Mn is 0.3 to 3.0 mass%, 0.001 To 0.400 mass% of Nb, and V is 0.001 to 0.400 mass%, 0.001 Mass% or more and 0.050 mass% or less of N, and Si is 1.0 mass% or less, 1.0 Mass% or less of Ti, Mo is 4.0 mass% or less, Cu is 0.50 mass% or less, The balance being Fe and unavoidable impurities, and A value A3 calculated by the following formula (3) of 0.120 or more and 0.500 or less, and A value A4 calculated by the following formula (4) of 9.40 or less, A3 = [ Nb ] M ＋［V］ M ..formula (3) A4＝1.22×（［Cr］ M ＋［Mo］ M ＋0.7×［Nb］ M ）－（［Ni］ M ＋35×［C］ M ＋20×［N］ M ＋0.25×［Cu］ M ） … (4) Wherein [ Nb ] M is a value in mass% of Nb content in the weld metal, [ V ] M is a value in mass% of V content in the weld metal, [ Cr ] M is a value in mass% of Cr content in the weld metal, [ Mo ] M is a value in mass% of Mo content in the weld metal, [ Ni ] M is a value in mass% of Ni content in the weld metal, [ C ] M is a value in mass% of C content in the weld metal, [ N ] M is a value in mass% of N content in the weld metal, and [ Cu ] M is a value in mass% of Cu content in the weld metal.
  6. 6. The weld metal of claim 5, wherein the weld metal is a metal of the type, P is 0.030 mass% or less, S is 0.030 mass% or less, Co is 0.500 mass% or less, W is 0.50 mass% or less, 12.0 Mass% or more and 14.0 mass% or less of Ni, 17.0 Mass% or more and 19.0 mass% or less of Cr, The Mo is 1.7 mass% or more and 2.5 mass% or less.

Description

Coated electrode, welded joint and weld metal Technical Field The present invention relates to coated electrodes, welded joints and weld metals. Background In general, in order to improve transportation and storage efficiency, a gas is liquefied at a low temperature and stored in a storage tank, and therefore, a structural member of the storage tank is required to have low temperature toughness in a liquefaction temperature range of the stored gas. For example, patent document 1 discloses a low-temperature stainless steel electrode for welding a stainless steel plate. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2-205293 Disclosure of Invention Problems to be solved by the invention In recent years, in consideration of the environment, hydrogen is being considered as a fuel for power generation, automobiles, or the like, and the demand for hydrogen is increasing. With this, there is an increasing demand for storage tanks capable of safely storing liquefied hydrogen. Specifically, it is required to be usable even in an extremely low temperature range, for example, around-253 ℃ or more, which is lower than the temperature used in a normal liquefied storage tank. Therefore, it is desirable to develop a coated electrode that can handle welding of structures in lower temperature regions. As an index of low-temperature toughness of the weld metal for such a low-temperature storage tank, a value of lateral expansion is required. However, the coated electrode described in patent document 1 does not consider the lateral expansion. The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a coated electrode used for welding a structure in a very low temperature range, which can provide a welded metal having excellent strength and a lateral expansion amount of not less than a desired value, and a welded joint and a welded metal obtained using the coated electrode. Means for solving the problems As a result of intensive studies, the inventors of the present invention have found that it is effective to control the ferrite amount by controlling the total amount of Nb and V in the electrode and by setting the value obtained by a calculation formula using Cr equivalent and Ni equivalent to a predetermined range in order to obtain a weld metal exhibiting excellent strength and lateral expansion in an extremely low temperature region. The present invention has been made based on the above-described findings. The above object of the present invention can be achieved by the following constitution of [1] relating to a coated electrode. [1] A coated electrode comprising, relative to the total mass of the electrode: Fe:30 mass% or more 55 mass% or less, 0.001 To 0.020 mass% (excluding C in carbonate), Cr is 10.0 to 30.0 mass%, Ni is 6.0 to 20.0 mass%, Nb:0.001 mass% or more 0.400 mass% or less, V is 0.001 to 0.400 mass%, and N is not less than 0.001% by mass and not more than 0.020% by mass Mo is 4.0 mass% or less, Cu is 0.50 mass% or less, A value A1 calculated by the following formula (1) is 0.120 to 0.500, A2 is a value calculated by the following formula (2) of 0.10 or less. A1 = [ Nb ] W＋［V］W..formula (1) A2＝1.22×（［Cr］W＋［Mo］W＋0.7×［Nb］W）－（［Ni］W＋35×［C］W＋20×［N］W＋0.25×［Cu］W）－10.0 … (2) Wherein [ Nb ] W is a value in mass% of Nb content in the covered electrode, [ V ] W is a value in mass% of V content in the covered electrode, [ Cr ] W is a value in mass% of Cr content in the covered electrode, [ Mo ] W is a value in mass% of Mo content in the covered electrode, [ Ni ] W is a value in mass% of Ni content in the covered electrode, [ C ] W is a value in mass% of C content in the covered electrode, [ N ] W is a value in mass% of N content in the covered electrode, and [ Cu ] W is a value in mass% of Cu content in the covered electrode. In addition, preferred embodiments of the present invention relating to coated electrodes are described in the following [2] to [3]. [2] The coated electrode according to [1], characterized by further comprising, with respect to the total mass of the electrode: F is 0.50 to 3.00 mass%, Ca:3.0 mass% or more and 9.0 mass% or less, Mn is 0.1 to 6.0 mass%, TiO 2: 5.0 mass% or more 25.0 mass% or less, The SiO 2 conversion value of the metal Si and the Si compound is 3.0 mass% or more and 8.0 mass% or less, Na of 0.05 to 0.50 mass% inclusive and 0.05 Mass% or more and 1.50 mass% or less, and The reduced value of ZrO 2 of the metal Zr and Zr compound is less than 2.0 mass%, The MgO equivalent value of the metal Mg and the Mg compound is 1.0 mass% or less, P is 0.030 mass% or less, 0.030 Mass% or less of S, 0.30 Mass% or less of Co, W is 0.50 mass% or less, REM 0.50 mass% or less, 1.0 Mass% or less of Ti, 0.3 Mass% or less of Al, Less than 2.0 mass% of Al 2O3, Li is 0.50 mass% or less. [3] The coated electrode according to [1] or [2], characterized in that, 7.0 Mass% or more and 10.0