CN104907735A - Copper-niobium (Cu-Nb) welding wire for welding titanium-pipeline steel composite plates and preparation method - Google Patents

Abstract

The invention discloses a Cu-Nb welding wire for welding titanium-pipeline steel composite plates, which comprises a coating and a welding core, wherein the coating is a red copper strip and the welding core is niobium powder. The invention also discloses a preparation method thereof: pour the dried niobium powder into a feeder, fill it into a pre-drawn copper tape with a U-shaped groove, and draw it to a welding wire with a diameter of 1.2 mm. The Cu-Nb welding wire of the present invention is suitable for manual argon tungsten arc welding and automatic argon tungsten arc welding; as a transition layer, it can effectively avoid the generation of intermetallic compounds between titanium and steel, and can also make the structure of titanium and steel good The fusion welding of titanium-pipeline steel composite plates is realized; the preparation process is simple, the efficiency is high, and it is convenient for large-scale batch production.

Description

Cu-Nb welding wire for welding titanium-pipeline steel composite plate and preparation method thereof

technical field

The invention belongs to the technical field of welding materials and their preparation, and in particular relates to a Cu-Nb welding wire for welding titanium-pipeline steel composite plates, and also relates to a preparation method of the welding wire.

Background technique

The titanium-pipeline steel bimetal composite plate with explosive compounding combines the advantages of the two metals. It not only has the strong corrosion resistance of titanium and the high strength and toughness of pipeline steel, but also saves titanium materials and reduces production costs. Titanium-pipeline steel composite panels are widely used in petroleum, chemical and other industries due to their low price and superior performance. However, due to the large difference in physical and chemical properties between titanium and steel, it is easy to form low-melting point eutectics and intermetallic brittle _compounds such as TiFe and TiFe2, which makes it difficult to weld and weld titanium-pipeline steel clad plates, which seriously hinders Its application in oil and gas, chemical and other pipelines. At present, there are few reports on the transition layer welding materials for the fusion welding connection of titanium-pipeline steel clad plates.

Contents of the invention

The object of the present invention is to provide a Cu-Nb welding wire for welding titanium-pipeline steel clad plate, the welding wire can effectively avoid the production of titanium and steel intermetallic compounds as a transition layer, and combine the structures of titanium and steel well , to realize the welding butt joint of titanium-pipeline steel clad plate.

Another object of the present invention is to provide a method for preparing Cu-Nb welding wire for welding titanium-pipeline steel composite plates.

The technical scheme adopted in the present invention is that the Cu-Nb welding wire used for welding titanium-pipeline steel composite plates includes a coating and a welding core, wherein the coating is copper strip and the welding core is niobium powder.

The present invention is also characterized in that,

The purity of the niobium powder is ≥99.95%, and the particle size is 100 mesh.

Another technical solution adopted in the present invention is, the preparation method of Cu-Nb welding wire for welding titanium-pipeline steel composite plate, specifically implement according to the following steps:

Step 1, place the niobium powder in a clean and dry vessel, put it in a vacuum furnace, heat it to 150°C, and keep it warm for 1 hour;

Step 2, put the copper strip on the tape unwinding machine, and roll the U-shaped groove after passing through the copper strip cleaning equipment; then grind the front end of the copper strip on the wire rolling machine, put it into a mold with an aperture of 2.5mm, and then pass The forming machine carries out the jointing of the copper tape to make a pre-drawn tape with a dense interface;

Step 3, pour the niobium powder dried in step 1 into the feeder, fill it into the pre-drawn belt with U-shaped grooves, control the filling rate of the niobium powder to 10-20%, and draw it into a welding wire with a diameter of 2.5mm ;

Step 4, put the welding wire obtained in step 3 on the reducing machine, change the molds with different apertures to reduce the diameter step by step, each time the diameter reduction range is 0.2mm, and finally obtain a Cu-Nb welding wire with a diameter of 1.2mm.

The present invention is also characterized in that,

The purity of the niobium powder in step 1 is ≥99.95%, and the particle size is 100 mesh.

The beneficial effect of the present invention is,

1. the Cu-Nb welding wire used for welding titanium-pipeline steel composite plate of the present invention has the following advantages: (1) the Cu-Nb welding wire of the present invention is applicable to manual argon tungsten arc welding and automatic argon tungsten arc welding; (2) ) The Cu-Nb welding wire of the present invention can be used as the transition layer to effectively avoid the generation of titanium and steel intermetallic compounds, and can also combine the structures of titanium and steel well to realize the welding butt joint of titanium-pipeline steel composite plates; ( 3) The titanium-pipeline steel composite plate is opened with an asymmetrical X-shaped groove, and the steel layer is first welded with the pipeline steel welding wire, then the transition layer is welded with the flux-cored welding wire of the present invention, and finally the titanium layer is welded with the pure titanium welding wire, and the resulting welded joint Excellent performance.

2. The preparation method of Cu-Nb welding wire for welding titanium-pipeline steel composite plate of the present invention has simple powder components, high purity, simple preparation process, high efficiency, and is convenient for large-scale batch production.

Description of drawings

Fig. 1 is the metallographic structure diagram of the deposited metal in the weld zone of the Cu-Nb welding wire prepared in Example 1 for welding titanium-pipeline steel composite plate;

Figure 2 is a partially enlarged view of Figure 1;

Fig. 3 is the metallographic structure diagram of the deposited metal in the weld zone of the Cu-Nb welding wire prepared in Example 4 for welding the titanium-pipeline steel composite plate;

FIG. 4 is a partially enlarged view of FIG. 3 .

Detailed ways

The present invention will be described in detail below in conjunction with specific drawings and embodiments.

The Cu-Nb welding wire for welding titanium-pipeline steel composite plate of the present invention comprises a coating and a welding core, wherein the coating is a red copper strip and the welding core is niobium powder.

The size of the copper strip is 0.45mm in thickness and 7mm in width; the purity of niobium powder is ≥99.95%, and the particle size is 100 mesh.

When the copper element in the copper strip transitions from the welding wire to the weld, because the copper element does not form brittle intermetallic compounds with Fe and other elements in the steel, the combination is good during welding, and the melting point of copper is low and the fluidity is good. Crack initiation and propagation at the titanium-steel composite interface.

Nb element and titanium can form an infinite solid solution, which has good mutual solubility characteristics, can refine titanium grains, and improve the oxidation resistance of welded joints; and the limited solid solution of Nb element and Cu element reduces the intermetallic compound between titanium and copper generation.

The preparation method of the above-mentioned Cu-Nb welding wire for welding titanium-pipeline steel composite plate is implemented according to the following steps:

Step 1, put the niobium powder with a purity of ≥99.95% and a particle size of 100 mesh in a clean and dry vessel, put it in a vacuum furnace, heat it to 150°C, and keep it warm for 1 hour;

Step 2, put the copper strip on the tape unwinding machine, and roll the U-shaped groove after passing through the copper strip cleaning equipment; then grind the front end of the copper strip on the wire rolling machine, put it into a mold with an aperture of 2.5mm, and then pass The forming machine carries out the jointing of the copper tape to make a pre-drawn tape with a dense interface;

Step 3, pour the niobium powder dried in step 1 into the feeder, fill it into the pre-drawn belt with U-shaped grooves, control the filling rate of the niobium powder to 10-20%, and draw it into a welding wire with a diameter of 2.5mm ;

Step 4, put the welding wire obtained in step 3 on the reducing machine, change the molds with different apertures to reduce the diameter step by step, each time the diameter reduction range is 0.2mm, and finally obtain a Cu-Nb welding wire with a diameter of 1.2mm.

Example 1

Step 1, put the niobium powder with a purity of ≥99.95% and a particle size of 100 mesh in a clean and dry vessel, put it in a vacuum furnace, heat it to 150°C, and keep it warm for 1 hour;

Step 2, put the copper strip on the tape unwinding machine, and roll the U-shaped groove after passing through the copper strip cleaning equipment; then grind the front end of the copper strip on the wire rolling machine, put it into a mold with an aperture of 2.5mm, and then pass The forming machine carries out the jointing of the copper tape to make a pre-drawn tape with a dense interface;

Step 3, pour the niobium powder dried in step 1 on the feeder, fill it into the pre-drawn belt with U-shaped grooves, control the filling rate of the niobium powder to 10%, and draw it into a welding wire with a diameter of 2.5 mm;

Step 4, put the welding wire obtained in step 3 on the reducing machine, change the molds with different apertures to reduce the diameter step by step, each time the diameter reduction range is 0.2mm, and finally obtain a Cu-Nb welding wire with a diameter of 1.2mm.

With the Cu-Nb welding wire (transition layer) prepared in Example 1, cooperate with pure titanium wire (titanium layer), YCGX80 pipeline steel welding wire (steel layer) welding titanium-pipeline steel (TA1-X80) composite plate, welding process is: titanium - Pipeline steel (TA1-X80) clad plate has an asymmetrical X-shaped bevel (titanium layer on top, steel layer on the bottom), steel side bevel angle is 60°, titanium side bevel angle is 90°. The steel layer is welded first, using CO ₂ gas shielded welding, and the welding current is 200A. Both the transition layer and the titanium layer are welded by manual argon tungsten arc welding, the welding current of the transition layer is 130A, and the welding current of the titanium layer is 120A.

After testing, the mechanical properties of the joint are: tensile strength 482MPa, yield strength 385MPa, elongation after fracture 15%, reduction of area 30%, impact energy at room temperature 32.3J.

As shown in Figure 1, there is no obvious fusion line between TA1 and the transition layer, and the transition layer structure and titanium structure interpenetrate and penetrate each other; the transition layer structure is a solid solution structure with Cu as the matrix; due to the infinite solid solution of Nb and β-Ti, As the temperature rises, Nb element diffuses into the titanium layer to form a massive solid solution structure. It can be seen from Figure 2 that there is a transition zone of about 10 μm between the transition layer and the steel layer, which prevents the diffusion of Fe to the titanium layer, and part of the Cu element diffuses into the steel layer, ensuring good mechanical properties of the weld.

Example 2

Step 1, put the niobium powder with a purity of ≥99.95% and a particle size of 100 mesh in a clean and dry vessel, put it in a vacuum furnace, heat it to 150°C, and keep it warm for 1 hour;

Step 2, put the copper strip on the tape unwinding machine, and roll the U-shaped groove after passing through the copper strip cleaning equipment; then grind the front end of the copper strip on the wire rolling machine, put it into a mold with an aperture of 2.5mm, and then pass The forming machine carries out the jointing of the copper tape to make a pre-drawn tape with a dense interface;

Step 3, pour the niobium powder dried in step 1 into the feeder, fill it into the pre-drawn belt with U-shaped grooves, control the filling rate of the niobium powder to 13%, and draw it into a welding wire with a diameter of 2.5 mm;

Step 4, put the welding wire obtained in step 3 on the reducing machine, change the molds with different apertures to reduce the diameter step by step, each time the diameter reduction range is 0.2mm, and finally obtain a Cu-Nb welding wire with a diameter of 1.2mm.

With the Cu-Nb welding wire (transition layer) prepared in Example 2, cooperate with pure titanium wire (titanium layer), YCGX80 pipeline steel welding wire (steel layer) welding titanium-pipeline steel (TA1-X80) composite plate, welding process is: titanium - Pipeline steel (TA1-X80) clad plate has an asymmetrical X-shaped bevel (titanium layer on top, steel layer on the bottom), steel side bevel angle is 60°, titanium side bevel angle is 90°. The steel layer is welded first, using CO ₂ gas shielded welding, and the welding current is 205A. Both the transition layer and the titanium layer are welded by manual argon tungsten arc welding. The welding current of the transition layer is 135A, and that of the titanium layer is 120A.

After testing, the mechanical properties of the joint are: tensile strength 490MPa, yield strength 387MPa, elongation after fracture 13%, reduction of area 31%, impact energy at room temperature 34.3J.

Example 3

Step 1, put the niobium powder with a purity of ≥99.95% and a particle size of 100 mesh in a clean and dry vessel, put it in a vacuum furnace, heat it to 150°C, and keep it warm for 1 hour;

Step 2, put the copper strip on the tape unwinding machine, and roll the U-shaped groove after passing through the copper strip cleaning equipment; then grind the front end of the copper strip on the wire rolling machine, put it into a mold with an aperture of 2.5mm, and then pass The forming machine carries out the jointing of the copper tape to make a pre-drawn tape with a dense interface;

Step 3, pour the niobium powder dried in step 1 on the feeder, fill it into the pre-drawn belt with U-shaped grooves, control the filling rate of the niobium powder to 15%, and draw it into a welding wire with a diameter of 2.5 mm;

Step 4, put the welding wire obtained in step 3 on the reducing machine, change the molds with different apertures to reduce the diameter step by step, each time the diameter reduction range is 0.2mm, and finally obtain a Cu-Nb welding wire with a diameter of 1.2mm.

With the Cu-Nb welding wire (transition layer) prepared in embodiment 3, coordinate pure titanium wire (titanium layer), YCGX80 pipeline steel welding wire (steel layer) welding titanium-pipeline steel (TA1-X80) composite plate, welding process is: titanium - Pipeline steel (TA1-X80) clad plate has an asymmetrical X-shaped bevel (titanium layer on the top, steel layer on the bottom), the steel side bevel angle is 60°, and the titanium side bevel angle is 90°. The steel layer is welded first, using CO ₂ gas shielded welding, and the welding current is 212A. Both the transition layer and the titanium layer are welded by manual argon tungsten arc welding. The welding current of the transition layer is 133A, and the welding current of the titanium layer is 125A.

After testing, the mechanical properties of the joint are: tensile strength 494MPa, yield strength 394MPa, elongation after fracture 12%, reduction of area 29%, impact energy at room temperature 35J.

Example 4

Step 1, put the niobium powder with a purity of ≥99.95% and a particle size of 100 mesh in a clean and dry vessel, put it in a vacuum furnace, heat it to 150°C, and keep it warm for 1 hour;

Step 2, put the copper strip on the tape unwinding machine, and roll the U-shaped groove after passing through the copper strip cleaning equipment; then grind the front end of the copper strip on the wire rolling machine, put it into a mold with an aperture of 2.5mm, and then pass The forming machine carries out the jointing of the copper tape to make a pre-drawn tape with a dense interface;

Step 3, pour the niobium powder dried in step 1 into the feeder, fill it into the pre-drawn belt with U-shaped grooves, control the filling rate of the niobium powder to 20%, and draw it into a welding wire with a diameter of 2.5 mm;

Step 4, put the welding wire obtained in step 3 on the reducing machine, change the molds with different apertures to reduce the diameter step by step, each time the diameter reduction range is 0.2mm, and finally obtain a Cu-Nb welding wire with a diameter of 1.2mm.

With the Cu-Nb welding wire (transition layer) prepared in embodiment 4, coordinate pure titanium wire (titanium layer), YCGX80 pipeline steel welding wire (steel layer) welding titanium-pipeline steel (TA1-X80) composite plate, welding process is: titanium - Pipeline steel (TA1-X80) clad plate has an asymmetrical X-shaped bevel (titanium layer on top, steel layer on the bottom), steel side bevel angle is 60°, titanium side bevel angle is 90°. The steel layer is welded first, using CO ₂ gas shielded welding, and the welding current is 206A. Both the transition layer and the titanium layer are welded by manual argon tungsten arc welding. The welding current of the transition layer is 134A, and that of the titanium layer is 118A.

After testing, the mechanical properties of the joint are: tensile strength 492MPa, yield strength 390MPa, elongation after fracture 11%, reduction of area 28%, impact energy at room temperature 33J.

As shown in Figure 3, the fusion line between TA1 and the transition layer is not obvious, the transition layer structure and the titanium structure are interspersed with each other, the grains of the titanium layer are fine, and the diffusion distance of the transition layer metal to the titanium layer is slightly larger than that of Example 1; the transition The layer structure is a solid solution structure with Cu as the matrix; it can be seen from Figure 4 that the transition zone between the transition layer and the steel layer is small, the steel layer structure diffuses less to the transition layer, and some Cu elements diffuse into the steel layer to form solid solution. The transition layer metal prevents the diffusion between Ti and Fe very well, avoiding the generation of brittle intermetallic compounds.

Claims (4)

1. The Cu-Nb welding wire for welding titanium-pipeline steel composite plate is characterized in that it comprises a coating and a welding core, wherein the coating is a red copper strip and the welding core is niobium powder. 2. The Cu-Nb welding wire for welding titanium-pipeline steel clad plate according to claim 1, characterized in that the purity of the niobium powder is ≥99.95%, and the particle size is 100 mesh. 3. the preparation method of Cu-Nb welding wire for titanium-pipeline steel composite plate welding is characterized in that, specifically implement according to the following steps: Step 1, place the niobium powder in a clean and dry vessel, put it in a vacuum furnace, heat it to 150°C, and keep it warm for 1 hour; Step 2, put the copper strip on the tape unwinding machine, and roll the U-shaped groove after passing through the copper strip cleaning equipment; then grind the front end of the copper strip on the wire rolling machine, put it into a mold with an aperture of 2.5mm, and then pass The forming machine carries out the jointing of the copper tape to make a pre-drawn tape with a dense interface; Step 3, pour the niobium powder dried in step 1 into the feeder, fill it into the pre-drawn belt with U-shaped grooves, control the filling rate of the niobium powder to 10-20%, and draw it into a welding wire with a diameter of 2.5mm ; Step 4, put the welding wire obtained in step 3 on the reducing machine, change the molds with different apertures to reduce the diameter step by step, each time the diameter reduction range is 0.2mm, and finally obtain a Cu-Nb welding wire with a diameter of 1.2mm. 4. The method for preparing Cu-Nb welding wire for welding titanium-pipeline steel clad plate according to claim 3, characterized in that in step 1, the purity of the niobium powder is ≥99.95%, and the particle size is 100 mesh.