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CN-121132094-B - Welding flux and double-wire submerged arc welding method for stainless steel by using same

CN121132094BCN 121132094 BCN121132094 BCN 121132094BCN-121132094-B

Abstract

The invention provides a flux and a double-wire submerged arc welding method for stainless steel, and relates to the technical field of stainless steel welding. The welding flux consists of, by mass, from SiO 2 % to 20%, from a calcium magnesium manganese mixture 50% to 70%, from K 2 S 0.01%-0.035%;KH 2 PO 4 to 0.02% to 0.04%, from a binder 15% to 45%, from CaF 2 and CaO, mgO, mnO, from a mixture of three oxides of CaF 2 and CaO, mgO, mnO in a mass ratio of (23-26) to (39-42), and from any one of vaseline, paraffin oil, mineral oil or acrylic resin solution. The flux can adapt to direct current and alternating current simultaneously by selecting substances and adjusting the proportion, has good deslagging performance, is not easy to generate air holes, improves the high-temperature wettability of the flux, and is more suitable for high-speed welding.

Inventors

  • Lv Zhaokui
  • Tian Fazheng
  • FU HUAIBO
  • CHEN CHUNYANG
  • LIU YUPENG
  • BAO GUOPING
  • CHEN XU
  • LI TONGYANG
  • Lei Liangdong
  • WANG ZIHUAN
  • LI PEIHAO
  • WANG GUOYIN
  • LIU SIYU

Assignees

  • 瀚洋重工装备制造(天津)有限公司

Dates

Publication Date
20260512
Application Date
20251010

Claims (9)

  1. 1. The welding flux is characterized by being prepared from the following raw materials in percentage by mass: SiO 2 10%-20%; 50% -70% of a calcium-magnesium-manganese mixture; K 2 S0.01%-0.035%; KH 2 PO 4 0.02%-0.04%; Li 2 CO 3 0.5% - 1.5%; La 2 O 3 0.1% - 0.5%; 15% -45% of adhesive; wherein the calcium-magnesium-manganese mixture consists of CaF 2 and CaO, mgO, mnO; The mass ratio of the mixture of three oxides of CaF 2 and CaO, mgO, mnO is (23-26): 39-42; the binder is any one of vaseline, paraffin oil, mineral oil or acrylic resin solution; CaO, mgO, mnO the mass ratio of the three oxides is 2:1:1.
  2. 2. A solder according to claim 1, wherein, SiO 2 18%; 64.67% Of a calcium-magnesium-manganese mixture; K 2 S0.02%; KH 2 PO 4 0.03%; Li 2 CO 3 1.0%; La 2 O 3 0.3%; 15.98% of binder.
  3. 3. The welding flux as defined in claim 1, wherein the mixture of three oxides CaF 2 and CaO, mgO, mnO is at a mass ratio of 25:40.
  4. 4. Use of the flux of any one of claims 1-3 in double wire submerged arc welding of stainless steel.
  5. 5. A method of double wire submerged arc welding of stainless steel with the flux as defined in any one of claims 1 to 3, comprising the steps of: S1, thoroughly removing impurities within a range of at least 30mm at the groove until metallic luster is exposed; S2, spot-welding is carried out on the single stainless steel welding wire under the flux layer, and then backing welding is carried out on the single stainless steel welding wire; s3, performing filler welding or cover welding on the single stainless steel welding wire under the flux layer; And S4, finally, performing high-speed filling welding by using two stainless steel welding wires.
  6. 6. The method for double wire submerged arc welding of stainless steel with flux according to claim 5, wherein the welding speed of the high speed filler welding in step S4 is 600mm/min to 700mm/min.
  7. 7. The method for double wire submerged arc welding of stainless steel with flux according to claim 5, wherein the step S4 specifically comprises: the two stainless steel welding wires adopt a cooperative welding mode of a front wire and a rear wire, the front wire adopts direct current pulse current, and the rear wire adopts alternating current square wave current.
  8. 8. The method for double wire submerged arc welding of stainless steel with the flux according to claim 7, wherein the peak current of the direct current pulse current is 700-750A, the base current is 300-350A, the frequency is 80-120 Hz, the effective value of the alternating square wave current is 550-600A, and the alternating balance ratio is 30-40% EP.
  9. 9. The method of double wire submerged arc welding of stainless steel with flux according to claim 5, wherein the heat input of the high speed filler welding is 40-42 KJ/min.

Description

Welding flux and double-wire submerged arc welding method for stainless steel by using same Technical Field The invention relates to the technical field of stainless steel welding, in particular to a welding flux, application and a double-wire submerged arc welding method for stainless steel. Background Based on the current technical state of the stainless steel welding field, the traditional submerged arc welding flux has remarkable limitations in coping with high alloy materials such as austenitic stainless steel and the like, on one hand, the conventional fluorine-base welding flux has good deoxidizing capability, but is easy to cause deslagging difficulty due to insufficient slag viscosity in a high-speed double-wire welding process, slag is easy to remain on the surface of a welding line, and the subsequent cleaning cost is increased, on the other hand, the application of the conventional welding flux to sulfur and phosphorus elements generally maintains a cautious attitude, and thermal cracking or embrittlement tendency is possibly caused by excessive addition, and is more obvious under the condition of high heat input. The double-wire submerged arc welding process has strict requirements on the metallurgical stability of the welding flux, the problems of unstable electric arc, increased air hole defects and the like easily occur when the welding speed exceeds 550mm/min in the existing formula, and the existing formula is difficult to match with the modern high-efficiency welding requirements. Especially for thick plate stainless steel structures (such as chemical containers and pipelines), the traditional method needs multilayer and multi-channel welding, and has low efficiency and prominent coarsening risk of grains in a heat affected zone. Besides, the double-wire submerged arc welding process in the prior art is complex, the applicability is poor, and the practical application scene is limited. Therefore, development of a novel flux system is needed to be developed, and on the premise of guaranteeing the metallurgical quality of a welding line, high-speed welding adaptability, slag self-release property and trace element controllability are considered to break through the technical bottleneck of efficient welding of stainless steel. In view of this, the present invention has been proposed. Disclosure of Invention In order to solve the technical problems, the invention provides the flux which can adapt to direct current and alternating current simultaneously through the selection and the proportioning adjustment of substances, has good deslagging performance, is not easy to generate air holes, improves the high-temperature wettability of the flux, and can be more suitable for high-speed welding. The invention also provides application of the flux in double-wire submerged arc welding of stainless steel. The invention also provides a double-wire submerged arc welding method for stainless steel by using the welding flux, which has simple process flow, and greatly improves the welding speed and the production efficiency compared with single-wire submerged arc welding. In order to achieve the aim of the invention, the invention provides a welding flux which is mainly prepared from the following raw materials in percentage by mass: SiO210%-20%; 50% -70% of a calcium-magnesium-manganese mixture; K2S0.01%-0.035%; KH2PO40.02%-0.04%; Li2CO30.5% - 1.5%; La2O30.1% - 0.5%; 15% -45% of adhesive; wherein the calcium-magnesium-manganese mixture consists of CaF 2 and CaO, mgO, mnO; The mass ratio of the mixture of three oxides of CaF 2 and CaO, mgO, mnO is (23-26): 39-42; The basicity index of the flux is 2.0-2.6, the particle ratio of 0.2-0.45mm in the particle size distribution is more than or equal to 60%, and the slag viscosity at 1300 ℃ is 0.3-0.8 Pa.s; The binder is any one of vaseline, paraffin oil, mineral oil or acrylic resin solution. Further, siO 2%; 64.67% of a calcium-magnesium-manganese mixture; K2S0.02%; KH2PO40.03%; Li2CO31.0%; La2O30.3%; 15.98% of binder; The basicity index of the flux was 2.4, the particle size distribution was 70% with 0.2-0.45mm particles, and the slag viscosity at 1300 ℃ was 0.5pa·s. Further, the mass ratio of the mixture of three oxides of CaF 2 and CaO, mgO, mnO is 25:40. Further, the mass ratio of CaO, mgO, mnO oxides is 2:1:1. The invention also provides application of the flux in double-wire submerged arc welding of stainless steel. The invention also provides a double-wire submerged arc welding method of the stainless steel, which comprises the following steps: S1, thoroughly removing impurities within a range of at least 30mm at the groove until metallic luster is exposed; S2, spot-welding is carried out on the single stainless steel welding wire under the flux layer, and then backing welding is carried out on the single stainless steel welding wire; s3, performing filler welding or cover welding on the single stainless steel welding wire under the flux layer; And S4, fi