阅读说明：本技术 一种与抗裂性优异的带极堆焊镍基合金焊带配合使用的焊剂 (Flux used in cooperation with strip surfacing nickel-based alloy welding strip with excellent crack resistance ) 是由 冯伟 徐锴 陈佩寅 邹力维 郭枭 曹宇堃 胡晓波 张庆素 魏涛 朱厚国 郑庆铭 于 2019-10-08 设计创作，主要内容包括：一种与抗裂性优异的带极堆焊镍基合金焊带配合使用的焊剂,本发明涉及焊接领域,尤其涉及一种抗裂性优异的镍基合金焊剂。本发明要解决现有大面积堆焊镍基合金微小裂纹难以控制的技术问题。焊剂成分由CaF<Sub>2</Sub>、SiO<Sub>2</Sub>、Al<Sub>2</Sub>O<Sub>3</Sub>、CaO、NaF、MgO、Cr<Sub>2</Sub>O<Sub>3</Sub>和合金剂组成,焊带成分由C、Si、Mn、S、P、Ni、Cr、Nb、Cu、Al、Ti、Co、Mo和余量铁组成。本发明提出一种与抗裂性优异的带极堆焊镍基合金焊带配合使用的焊剂,能够大幅度提高堆焊金属抗高温失塑性裂纹的能力,其中焊剂与焊带要配套使用,焊剂选用含S、P等杂质元素低的粉料和合金作为焊剂制备原材料,调整合金化元素Nb、Ti、Mn和Mo等的含量,以降低熔敷金属结晶裂纹和DDC的敏感性。本发明方法用于多层焊接工艺。(The invention relates to the field of welding, in particular to a nickel-based alloy welding flux with excellent crack resistance. The invention aims to solve the technical problem that the tiny cracks of the existing large-area surfacing nickel-based alloy are difficult to control. The flux component is CaF 2 、SiO 2 、Al 2 O 3 、CaO、NaF、MgO、Cr 2 O 3 And the welding strip consists of C, Si, Mn, S, P, Ni, Cr, Nb, Cu, Al, Ti, Co, Mo and the balance of iron. The invention provides a welding flux which is matched with a strip surfacing nickel-based alloy welding strip with excellent crack resistance for use, and can greatly improve the high-temperature plasticity-loss crack resistance of surfacing metal, wherein the welding flux is matched with the welding strip for use, powder and alloy containing low impurity elements such as S, P are selected as raw materials for preparing the welding flux, and alloying elements such as Nb, Ti, Mn, Mo and the like are adjustedTo reduce the susceptibility of deposited metal crystal cracking and DDC. The method of the invention is used for multilayer welding process.)

1. The flux is used together with a strip surfacing nickel-based alloy welding strip with excellent crack resistance, and is characterized in that the flux comprises the following components in parts by weight: CaF₂: 25 to 50 parts of SiO₂: 5 to 20 parts of Al₂O₃: 10-40 parts of CaO: 8-20 parts of NaF (sodium fluoride) less than or equal to 5 parts of MgO: 4 to 15 parts of Cr₂O₃Not more than 5 parts and not more than 8 parts of alloying agent.

2. The flux used in combination with the strip surfacing nickel-based alloy welding strip with excellent crack resistance according to claim 1, is characterized in that the welding strip comprises the following components in percentage by mass: c: 0.01 to 0.03%, Si: 0.10 to 0.50%, Mn: 0.5-1.0%, S: < 0.015%, P: < 0.020%, Ni: 52-62%, Cr: 28.5 to 31.0%, Nb: 2.1-4.0%, Cu: < 0.30%, Al: < 0.50%, Ti: 0.50 to 0.52%, Co: <0.003, Mo: 3.0-5.0% and the balance of iron.

3. The flux used in combination with the strip surfacing nickel-based alloy welding strip with excellent crack resistance according to claim 2 is characterized in that the welding strip comprises the following components in percentage by mass: c: 0.02 to 0.025%, Si: 0.10 to 0.40%, Mn: 0.5-1.0%, S: < 0.005%, P: < 0.005%, Ni: 58-62%, Cr: 29.0 to 30.5%, Nb: 2.1-3.0%, Cu: < 0.30%, Al: < 0.50%, Ti: 0.50 to 0.52%, Co: <0.003, Mo: 3.0-3.25% and the balance of iron.

4. The flux according to claim 1, wherein CaF is used in combination with a strip surfacing nickel-based alloy welding strip having excellent crack resistance₂30 to 50 portions.

5. The flux according to claim 1, wherein the alloying agent is a mixed alloying agent of FeMo60 and FeNb 70.

6. The flux according to claim 1, wherein the basicity of the flux is 0.9 to 1.1.

7. The flux according to claim 1, wherein the particle size of the flux is 10 to 80 mesh.

8. The flux according to claim 1, which is used in combination with a strip surfacing nickel-based alloy weld strip having excellent crack resistance, characterized in that the flux is produced by a method comprising:

according to the mass portion, CaF₂: 25 to 50 parts of SiO₂: 5 to 20 parts of Al₂O₃: 10-40 parts of CaO: 8-20 parts of NaF (sodium fluoride) less than or equal to 5 parts of MgO: 4 to 15 parts of Cr₂O₃Uniformly mixing not more than 5 parts of the flux and not more than 8 parts of the alloying agent, adding 10-30 parts of sodium-potassium water glass with the modulus of 2.6, drying at a low temperature of 180-220 ℃, sintering at a high temperature of 750-810 ℃, and cooling along with a furnace to obtain the flux.

9. The flux according to claim 1, which is used in combination with a strip-deposited nickel-base alloy weld strip having excellent crack resistance, according to the method for dc electroslag strip deposition by combining the flux according to claim 1 with the weld strip according to claim 2, wherein the method comprises:

drying the welding flux at 350 ℃ for 2h, then matching with a welding strip, controlling the welding current to be 900-1050A, the magnetic control current to be 2.5A, the welding voltage to be 24-26V and the welding speed to be 150-180 mm/min, welding by adopting an edge lapping process of each welding pass, wherein the width of the edge lapping of each welding pass is 7-8mm, the thickness of the bead welding of each layer of the welding strip is 3-4mm, and the total thickness of the bead welding is 35mm, so as to obtain deposited metal, and finishing the method.

10. The flux according to claim 9, which is used in combination with a strip surfacing nickel-base alloy weld bead having excellent crack resistance, wherein the deposited metal comprises the following components in percentage by mass: c: < 0.04%; si: < 0.50%; mn: 0.5-1.0%; s: < 0.008%; p: < 0.008%; cr: 29.0-30.5%; nb: 1.5-2.5%; cu: < 0.30%; al: < 0.50%; ti: < 0.50%; mo: 3.0-3.25%; co: < 0.003%; ni: 58-62%; the total amount of Pb, Sb, Bi, As, Sn and B is less than or equal to 10 ppm; o is less than or equal to 50ppm and the balance is iron.

Technical Field

The invention relates to the field of welding, in particular to a nickel-based alloy welding flux with excellent crack resistance.

Background

With the development of nuclear industry, a large-area nickel-based alloy needs to be overlaid on the surface of one side of a tube plate of a steam generator of a pressurized water reactor nuclear power station, wherein a strip surfacing material is the most common method, the overlaying efficiency is high, and the main difficulty of nickel-based alloy welding is that the nickel-based alloy has high sensitivity to thermal cracks and is difficult to control micro cracks such as high-temperature plasticity loss cracks, crystallization cracks, stress corrosion cracks and the like, and at present, 52M type alloy welding strips are widely applied to overlaying of the tube plate of the steam generator of the nuclear power station, and 52M has high crack sensitivity. According to the requirements of nuclear power technology and corrosive medium, the material is gradually developed from INCONEL 600 to INCONEL 690, the build-up welding material of the tube plate of the steam generator in the current third-generation nuclear power technology adopts the INCONEL 690 material, but the problems of DDC cracks and the like exist, the problem of crack sensitivity is solved, and the development of novel welding strip/welding flux is particularly important,

disclosure of Invention

The invention provides a flux which is matched with a strip surfacing nickel-based alloy welding strip with excellent crack resistance to solve the technical problem that the micro cracks of the conventional large-area surfacing nickel-based alloy are difficult to control.

The flux is used together with a strip surfacing nickel-based alloy welding strip with excellent crack resistance, and the CaF welding flux comprises the following components in parts by weight₂: 25 to 50 parts of SiO₂: 5 to 20 parts of Al₂O₃: 10-40 parts of CaO: 8-20 parts of NaF (sodium fluoride) less than or equal to 5 parts of MgO: 4 to 15 parts of Cr₂O₃Not more than 5 parts and not more than 8 parts of alloying agent.

Further, the welding strip comprises the following components in percentage by mass: c: 0.01 to 0.03%, Si: 0.10 to 0.50%, Mn: 0.5-1.0%, S: < 0.015%, P: < 0.020%, Ni: 52-62%, Cr: 28.5 to 31.0%, Nb: 2.1-4.0%, Cu: < 0.30%, Al: < 0.50%, Ti: 0.50 to 0.52%, Co: <0.003, Mo: 3.0-5.0% and the balance of iron.

Further, the welding strip comprises the following components in percentage by mass: c: 0.02 to 0.025%, Si: 0.10 to 0.40%, Mn: 0.5-1.0%, S: < 0.005%, P: < 0.005%, Ni: 58-62%, Cr: 29.0 to 30.5%, Nb: 2.1-3.0%, Cu: < 0.30%, Al: < 0.50%, Ti: 0.50 to 0.52%, Co: <0.003, Mo: 3.0-3.25% and the balance of iron.

Further, CaF₂30 to 50 portions.

Furthermore, the alloying agent comprises the components of FeMo60 and FeNb 70.

Wherein the mass ratio of FeMo60 to FeNb70 is 1: 1.

further, the alkalinity of the welding flux is 0.9-1.1.

Furthermore, the granularity of the welding flux is 10-80 meshes.

Further, the manufacturing method of the flux comprises the following steps:

according to the mass portion, CaF₂: 25 to 50 parts of SiO₂: 5 to 20 parts of Al₂O₃: 10-40 parts of CaO: 8-20 parts of NaF (sodium fluoride) less than or equal to 5 parts of MgO: 4 to 15 parts of Cr₂O₃Uniformly mixing not more than 5 parts of the flux and not more than 8 parts of the alloying agent, adding 10-30 parts of sodium-potassium water glass with the modulus of 2.6, drying at a low temperature of 180-220 ℃, sintering at a high temperature of 750-810 ℃, and cooling along with a furnace to obtain the flux.

Further, the method for performing direct-current electroslag strip surfacing by matching the flux with the welding strip comprises the following steps:

drying the welding flux at 350 ℃ for 2h, then matching with a welding strip, controlling the welding current to be 900-1050A, the magnetic control current to be 2.5A, the welding voltage to be 24-26V and the welding speed to be 150-180 mm/min, welding by adopting an edge lapping process of each welding pass, wherein the width of the edge lapping of each welding pass is 7-8mm, the thickness of the bead welding of each layer of the welding strip is 3-4mm, and the total thickness of the bead welding is 35mm, so as to obtain deposited metal, and finishing the method.

Further, the obtained deposited metal comprises the following components in percentage by mass: c: < 0.04%; si: < 0.50%; mn: 0.5-1.0%; s: < 0.008%; p: < 0.008%; cr: 29.0-30.5%; nb: 1.5-2.5%; cu: < 0.30%; al: < 0.50%; ti: < 0.50%; mo: 3.0-3.25%; co: < 0.003%; ni: 58-62%; the total amount of Pb, Sb, Bi, As, Sn and B is less than or equal to 10 ppm; o is less than or equal to 50ppm and the balance is iron.

According to the invention, the components and the contents of the components in the welding strip are adjusted, so that the welded deposited metal has good mechanical properties and excellent crack resistance, Cr in the welding strip is a key factor influencing caustic stress corrosion, when the Cr content is lower than 28%, the alloy caustic stress corrosion tendency is increased, and when the Cr content is 30%, the caustic stress corrosion tendency is minimum, so that the Cr content is controlled to be 28-31.5%; preferably, the concentration is controlled to be 29-30.5%.

The addition of Nb in the weld zone may enhance the intergranular corrosion resistance of the alloy on the one hand, since Nb has a stronger bonding force with C than Cr. On the other hand, the DDC crack sensitivity of the alloy can be effectively reduced by adding Nb, and Nb carbide is precipitated at grain boundaries to enable the grain boundaries to bend and meander more, so that the resistance of grain boundary sliding is increased. But the addition of Nb can simultaneously increase the crystallization interval of the alloy and increase the crystal crack sensitivity of the alloy, so that the Nb is controlled to be 2.1-4.0%; preferably, the content can be controlled to be 2.1-3.0%.

Harmful elements such as S, P and the like in the deposited metal can increase the sensitivity of hot cracks of the deposited metal, and the S content and the P content in the deposited metal are strictly controlled to be less than or equal to 0.005% and less than or equal to 0.008% in consideration of S, P metallurgical characteristics of a welding flux; si in the deposited metal can be segregated to form a low-melting-point eutectic component during solidification, and particularly, after the Si is combined with Ni, the Si in the deposited metal is controlled to be less than or equal to 0.60 percent; pb, Sb, Bi, As, Sn, B in the deposited metal are impurity elements which need to be mainly controlled in the welding process and have relatively adverse effect on crystal cracks, so that the Pb, Sb, Bi, As, Sn, B in the deposited metal is controlled to be less than or equal to 10 ppm; when the content of O element in the deposited metal is too high, the amount of inclusions of microscopic oxides is increased, so that a deoxidizer is added to the flux, and the content of O in the deposited metal is controlled to be less than or equal to 50 ppm.

The welding strip provided by the invention is matched with the welding flux provided by the invention, so that a stable welding process can be realized, and the surfacing metal with high deposition efficiency, low dilution rate, good slag detachability and attractive forming can be obtained.

The invention has the beneficial effects that:

the invention provides a welding flux which is matched with a strip surfacing nickel-based alloy welding strip with excellent crack resistance, and the welding flux can greatly improve the high-temperature plasticity-loss crack resistance of surfacing metal, wherein the welding flux is matched with the welding strip for use; the welding flux is electroslag type welding flux, powder and alloy containing low impurity elements such as S, P and the like are selected as raw materials for preparing the welding flux, and the contents of alloying elements such as Nb, Ti, Mn, Mo and the like are adjusted to reduce the sensitivity of deposited metal crystal cracks and DDC. The invention not only ensures the requirements of various mechanical properties and corrosion properties of the surfacing metal, but also has good welding process performance, is particularly suitable for multilayer welding process performance, has larger viscosity of nickel-based materials, solves the problem of slag adhesion in the process of welding multilayer welding, and has the characteristics of moderate alkalinity of the welding flux and strong process adaptability.

The flux has excellent slag removal performance, good spreading performance of a welding bead, no undercut phenomenon, no slag adhesion during multilayer welding, easy slag removal and solves key indexes of crystal cracks, DDC and the like of a nickel-based material, so that the flux has good mechanical property and corrosion resistance; the sensitivity to crystal cracking is extremely low; the sensitivity of high-temperature plasticity-loss cracks is extremely low; the surface crack-free surfacing layer metal has excellent mechanical property after the surfacing deposited metal tensile test piece is broken.

The method of the invention is used for multilayer welding process.

Detailed Description

The technical solution of the present invention is not limited to the specific embodiments listed below, and includes any combination of the specific embodiments.