CN110625127A - A kind of preparation method of cobalt-chromium-nickel-tungsten alloy solder powder - Google Patents

Abstract

The invention discloses a preparation method of cobalt-chromium-nickel-tungsten alloy brazing filler metal powder, which comprises the following steps: firstly, filling joints of a magnesium oxide crucible and heating for dehumidifying; secondly, uniformly mixing the raw materials, adding the mixture into a heated and dehumidified magnesium oxide crucible, and then putting the crucible into a smelting furnace of a vacuum induction smelting gas atomization powder making device for heating and smelting to obtain alloy liquid; and thirdly, flowing the alloy liquid out of a tundish of the vacuum induction melting gas atomization powder making device to an atomization chamber for atomization and dispersion, and cooling to obtain cobalt-chromium-nickel-tungsten alloy brazing filler metal powder. According to the invention, by virtue of crucible tamping process, raw material limitation and gas atomization process control, the cobalt-chromium-nickel-tungsten alloy brazing filler metal powder which is uniform and stable in chemical composition, low in impurity content, excellent in process performance, high in yield and suitable for batch production is obtained, and the requirements of various application fields on high-quality cobalt-chromium-nickel-tungsten alloy brazing filler metal powder are met.

Description

A kind of preparation method of cobalt-chromium-nickel-tungsten alloy solder powder

technical field

The invention belongs to the technical field of brazing material preparation, and in particular relates to a method for preparing cobalt-chromium-nickel-tungsten alloy solder powder.

Background technique

Cobalt-based superalloys have good high-temperature mechanical properties and oxidation resistance, and are important raw materials for the manufacture of engine parts. In the manufacturing process of various parts, welding technology is required. Since the cobalt-chromium-nickel-tungsten alloy solder contains many types of elements, up to seven elements, the properties of each element are greatly different, especially the high content of silicon and boron, which forms a high content of intermediate brittle phases, resulting in high brittleness of the alloy material and no rolling properties. Plasticity required for processing. When used in the field of brazing filler metal, it cannot be prepared into welding wire and welding strip, so it is an important way for the alloy to be used in high-temperature alloy welding to make it into brazing filler metal powder.

Generally, alloy solder powder is mostly prepared by centrifugal atomization powder making method or special gas atomization powder making method. For example, the powder raw materials used in cobalt-based superalloy powder metallurgy materials produced in Russia are prepared by centrifugal atomization method. However, centrifugal atomization method requires high equipment precision and long process flow. At present, there is no such processing equipment in China. The special gas atomization method (such as the induction heating gas atomization method without a crucible) needs to prepare a round rod with a certain diameter and a suitable length, and then heat it into a molten metal by induction. After that, the molten metal flows into the nozzle continuously without any contact. The powder is obtained by gas atomization. However, the process of this method is relatively complicated, and it is difficult to prepare alloy rods with high brittleness, which is not suitable for large-scale industrial production.

Vacuum induction melting gas atomization powder production has the characteristics of short process flow, wide adaptability and easy batch production. It is the most commonly used method for preparing alloy powder. However, due to the differences in the properties of the alloys, the different composition requirements, the control of oxygen content, the control of impurity components, and the requirements of particle size and yield, the key process technologies and methods are very different, and there is no specific rule to follow. Satisfy the preparation of cobalt-chromium-nickel-tungsten alloy solder.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for preparing cobalt-chromium-nickel-tungsten alloy solder powder for the above-mentioned deficiencies in the prior art. The method reduces the oxygen content and impurity content in the cobalt-chromium-nickel-tungsten alloy solder powder by limiting the crucible stamping process and raw materials, and improves the uniformity and stability of each component, and then through the vacuum induction melting gas atomization process control, which improves the yield of cobalt-chromium-nickel-tungsten alloy solder powder, and obtains cobalt-chromium-nickel-tungsten alloy solder powder with uniform and stable chemical composition, low impurity content, excellent process performance, high yield and suitable for mass production. Application fields require high-quality cobalt-chromium-nickel-tungsten alloy solder powder.

In order to solve the above technical problems, the technical solution adopted in the present invention is: a method for preparing cobalt-chromium-nickel-tungsten alloy solder powder, characterized in that the method comprises the following steps:

Step 1. Place the magnesia crucible in the induction melting coil, fill the magnesia crucible with magnesia sand and water glass, and then heat and dehumidify the magnesia crucible after the filling;

Step 2. Mix the raw materials such as electrolytic cobalt plate, electrolytic nickel plate, electrolytic chromium, sintered tungsten bar, high-purity silicon particles, nickel-boron intermediate alloy and high-purity carbon, and then add it to the magnesia after heating and dehumidification in step 1. Put it into the crucible, then put it into the melting furnace of the vacuum induction melting gas atomization powder making equipment, close the furnace door, evacuate the melting furnace to a vacuum degree of 1Pa to 10Pa, and then heat and melt to completely melt the raw materials into alloy liquid; The specific process of heating and smelting is as follows: heating until the raw materials start to melt, filling with argon until the vacuum degree is -0.04MPa~-0.02MPa, then heating until the raw materials are completely melted, and then raising the temperature to 1600°C~1700°C for heat preservation 10min～15min;

Step 3. Pour the alloy liquid obtained in step 2 into the tundish of the vacuum induction melting gas atomization powder making equipment, and flow out to the atomization chamber along the guide tube at the bottom of the tundish, and then flow into the atomization chamber Inject high-pressure argon gas, and the alloy liquid flowing out from the guide tube is atomized and dispersed into tiny droplets in the atomization chamber under the action of high-pressure argon gas flow, then falls and cools to form alloy powder, and the alloy powder is classified and screened to obtain Cobalt chromium nickel tungsten alloy solder powder.

The present invention adopts the vacuum induction smelting gas atomization method to prepare cobalt-chromium-nickel-tungsten alloy solder powder. Firstly, the oxygen content and impurity content in the cobalt-chromium-nickel-tungsten alloy solder powder are reduced by limiting the crucible stamping process and raw materials, and the improved The uniformity and stability of each component, and then through the control of the raw material smelting process and atomization process of the vacuum induction melting gas atomization method, it is ensured that no splash occurs during the raw material melting and smelting process, and the stability of each component in the alloy liquid is realized. Control, avoid the oxidation and burning of raw materials, and realize the complete alloying of each raw material, further improve the uniformity and stability of the chemical composition in the cobalt-chromium-nickel-tungsten alloy solder powder, and at the same time improve the quality of the cobalt-chromium-nickel-tungsten alloy solder powder The finished product rate of raw material powder has realized mass production.

The above-mentioned method for preparing cobalt-chromium-nickel-tungsten alloy solder powder is characterized in that in step 1, the temperature of heating and dehumidification is 900°C-1000°C, and the time is 8h-10h. The preferred temperature and time are conducive to fully removing the moisture and adsorbed oxygen on the surface of the magnesia crucible, ensuring the low impurity amount and low oxygen content of the magnesia crucible.

The preparation method of the above-mentioned cobalt-chromium-nickel-tungsten alloy solder powder is characterized in that the grade of the electrolytic cobalt plate described in step 2 is Co998, the grade of the electrolytic nickel plate is Ni9996, and the grade of the electrolytic chromium is JCr99-A , the grade of sintered tungsten strip is W-1, the grade of high-purity silicon particles is Si-2, and the high-purity carbon is the carbon spectrum electrode. The above-mentioned preferred raw materials have higher purity, which is beneficial to obtain cobalt-chromium-nickel-tungsten alloy solder powder with lower impurity content.

The above-mentioned method for preparing cobalt-chromium-nickel-tungsten alloy solder powder is characterized in that the tundish in step 3 is preheated to 1000°C to 1100°C before pouring the alloy liquid, and the diameter of the draft tube is 4mm ~ 6mm. The preheating of the tundish ensures that the high-temperature alloy liquid will not be cold after being introduced into the tundish, resulting in poor fluidity, solidification and blockage of the guide tube, which is conducive to efficient atomization; and the optimal diameter of the guide tube is also conducive to the alloy liquid Flow out to the atomization chamber for atomization and dispersion.

The above-mentioned method for preparing cobalt-chromium-nickel-tungsten alloy solder powder is characterized in that the pressure of high-pressure argon gas introduced in Step 3 is 2.5MPa-3.5MPa. The above inlet pressure ensures that the alloy liquid flowing out of the draft tube is carried into the atomization chamber by high-pressure argon gas for efficient atomization.

The above-mentioned preparation method of a cobalt-chromium-nickel-tungsten alloy solder powder is characterized in that the mass content of cobalt in the cobalt-chromium-nickel-tungsten alloy solder powder described in step 3 is 47.0% to 54.5%, and the mass content of chromium is 18.0%～20.0%, the mass content of nickel is 16.0%～18.0%, the mass content of tungsten is 3.5%～4.5%, the mass content of silicon is 7.0%～9.0%, the mass content of boron is 0.6%～1.0%, The mass content of carbon is 0.1% to 0.4%, the mass content of oxygen is less than 0.05%, the mass content of sulfur is less than 0.02%, the mass content of phosphorus is less than 0.02%, the mass content of aluminum is less than 0.05%, and the mass content of titanium is less than 0.05%. , the mass content of other impurities is less than 0.25%. The cobalt-chromium-nickel-tungsten alloy solder powder with the above composition content has low impurity content and excellent performance, and can meet the requirements of high-quality cobalt-chromium-nickel-tungsten alloy solder powder in various application fields.

Compared with the prior art, the present invention has the following advantages:

1. The present invention adopts the vacuum induction melting gas atomization method to prepare cobalt-chromium-nickel-tungsten alloy solder powder, through the control of the crucible stamping process and raw materials, and the raw material melting process and atomization process of the vacuum induction melting gas atomization method , reducing the oxygen content and impurity content in the cobalt-chromium-nickel-tungsten alloy solder powder, improving the uniformity and stability of each chemical composition, and at the same time improving the yield of cobalt-chromium-nickel-tungsten alloy solder powder and realizing batch production Production.

2. The present invention adopts vacuum induction smelting gas atomization to make powder, the process is simple and easy to realize, and avoids the excessive requirements on equipment and process of traditional centrifugal atomization and induction smelting without crucible.

3. The chemical components in the cobalt-chromium-nickel-tungsten alloy solder powder prepared by the present invention are uniform and stable, the total amount of impurities is less than 0.44%, wherein the oxygen content is less than 0.05%, the sulfur and phosphorus impurity contents are all less than 0.02%, aluminum, titanium The impurity content is less than 0.05%, and the yield of -100 mesh powder is greater than 85%. The process performance of the cobalt-chromium-nickel-tungsten alloy solder powder is excellent, especially the brazing spreadability and seam filling performance, and is suitable for mass production. Requirements for high-quality cobalt-chromium-nickel-tungsten alloy solder powder in various application fields.

The technical solutions of the present invention will be described in further detail below with reference to the drawings and embodiments.

Description of drawings

Figure 1 is a SEM image of the chromium-nickel-tungsten alloy solder powder prepared in Example 1 of the present invention.

Detailed ways

Example 1

This embodiment includes the following steps:

Step 1. Place the magnesia crucible in the induction melting coil, fill the magnesia crucible with magnesia sand and water glass, and then heat and dehumidify the magnesia crucible after the filling; The temperature is 900°C, and the time is 8h;

Step 2: 52.9kg of Co998 electrolytic cobalt plate, 10.2kg of Ni9996 electrolytic nickel plate, 18.5kg of JCr99-A electrolytic chromium, 3.8kg of W-1 sintered tungsten bar, 7.5kg of Si-2 silicon particles, 7kg Mix nickel-boron master alloy and 0.1kg carbon spectral electrode evenly, then add it into the magnesia crucible which has been heated and dehumidified in step 1, then put it into the melting furnace of the vacuum induction melting gas atomization powder making equipment, close the furnace door, Vacuumize the smelting furnace until the vacuum degree in the smelting furnace is 1Pa to 10Pa and heat and smelt to completely melt the raw materials into alloy liquid; the mass content of boron in the nickel-boron master alloy is 10%; the heat-melted The specific process is: heating up until the raw material starts to melt, filling with argon until the vacuum degree is -0.04MPa~-0.02MPa, then heating up until the raw material is completely melted, and then raising the temperature to 1600°C for 10 minutes;

Step 3. Pour the alloy liquid obtained in step 2 into the tundish preheated to 1000°C of the vacuum induction melting gas atomization powder making equipment, and flow out to the atomization chamber along the draft tube at the bottom of the tundish, and then to the The high-pressure argon gas is introduced into the atomization chamber, and the alloy liquid flowing out from the guide tube is atomized and dispersed into tiny droplets in the atomization chamber under the action of the high-pressure argon gas flow, and then falls and cools to form alloy powder. Grading and sieving to obtain cobalt-chromium-nickel-tungsten alloy solder powder whose chemical composition is Co-18.5Cr-16.5Ni-3.8W-7.5Si-0.7B-0.1C; the diameter of the guide tube is 4mm; the argon The gas feeding pressure is 2.5 MPa; the yield of -100 mesh powder in the cobalt-chromium-nickel-tungsten alloy solder powder is 87%.

After testing, the mass content of oxygen in the chromium-nickel-tungsten alloy solder powder prepared in this embodiment is 0.045%, the mass content of sulfur is 0.015%, the mass content of phosphorus is 0.017%, the mass content of aluminum is 0.021%, and the mass content of titanium is 0.015%. The mass content is 0.022%, and the mass content of other impurities is 0.24%, indicating that the quality of the chromium-nickel-tungsten alloy solder powder is uniform, the total amount of impurities and oxygen content are low, the process performance is superior, and it fully meets the needs of high-quality cobalt in various application fields. Technical requirements for chromium-nickel-tungsten alloy solder powder.

Fig. 1 is the SEM picture of the chromium-nickel-tungsten alloy solder powder prepared by the present embodiment, as can be seen from Fig. 1 the chromium-nickel-tungsten alloy solder powder prepared by the present embodiment is mostly spherical, and the particle size distribution is uniform, satellite powder The content is less.

Example 2

This embodiment includes the following steps:

Step 1. Place the magnesia crucible in the induction melting coil, fill the magnesia crucible with magnesia sand and water glass, and then heat and dehumidify the magnesia crucible after the filling; The temperature is 950°C, and the time is 9h;

Step 2: 51kg of Co998 electrolytic cobalt plate, 12.1kg of Ni9996 electrolytic nickel plate, 19kg of JCr99-A electrolytic chromium, 4kg of W-1 sintered tungsten bar, 8kg of Si-2 silicon grains, 5.7kg of nickel-boron intermediate Alloy and 0.2kg carbon spectrum electrode are mixed evenly and then added to the magnesia crucible which has been heated and dehumidified in step 1, and then put into the melting furnace of the vacuum induction melting gas atomization powder making equipment, close the furnace door, and put it into the melting furnace Vacuumize until the vacuum degree in the melting furnace is 1Pa to 10Pa and heat and smelt to completely melt the raw materials into alloy liquid; the mass content of boron in the nickel-boron master alloy is 14%; the specific process of the heating and smelting is as follows: : Heating up until the raw material starts to melt, fill it with argon until the vacuum degree is -0.04MPa~-0.02MPa, then heat up until the raw material is completely melted, then raise the temperature to 1650°C and keep it for 15min;

Step 3. Pour the alloy liquid obtained in step 2 into the tundish preheated to 1050°C of the vacuum induction melting gas atomization powder making equipment, and flow out to the atomization chamber along the draft tube at the bottom of the tundish, and then to the The high-pressure argon gas is introduced into the atomization chamber, and the alloy liquid flowing out from the guide tube is atomized and dispersed into tiny droplets in the atomization chamber under the action of the high-pressure argon gas flow, and then falls and cools to form alloy powder. Grading and sieving to obtain cobalt-chromium-nickel-tungsten alloy solder powder with a chemical composition of Co-19Cr-17Ni-4W-8Si-0.8B-0.2C; the diameter of the draft tube is 5mm; the introduction of the argon gas The pressure is 3 MPa; the yield of -100 mesh powder in the cobalt-chromium-nickel-tungsten alloy solder powder is 89%.

After testing, the mass content of oxygen in the chromium-nickel-tungsten alloy solder powder prepared in this embodiment is 0.04%, the mass content of sulfur is 0.012%, the mass content of phosphorus is 0.013%, the mass content of aluminum is 0.02%, and the mass content of titanium is 0.01%. The mass content is 0.02%, and the mass content of other impurities is 0.20%, indicating that the quality of the chromium-nickel-tungsten alloy solder powder is uniform, the total amount of impurities and oxygen content are low, the process performance is superior, and it fully meets the needs of high-quality cobalt in various application fields. Technical requirements for chromium-nickel-tungsten alloy solder powder.

Example 3

This embodiment includes the following steps:

Step 1. Place the magnesia crucible in the induction melting coil, fill the magnesia crucible with magnesia sand and water glass, and then heat and dehumidify the magnesia crucible after the filling; The temperature is 1000°C, and the time is 10h;

Step 2: 47.1kg of Co998 electrolytic cobalt plate, 13.1kg of Ni9996 electrolytic nickel plate, 20kg of JCr99-A electrolytic chromium, 4.5kg of W-1 sintered tungsten bar, 9kg of Si-2 silicon particles, 5.9kg of nickel boron The master alloy and 0.4kg carbon spectrum electrode are mixed evenly and then added to the magnesia crucible that has been heated and dehumidified in step 1, and then put into the melting furnace of the vacuum induction melting gas atomization powder making equipment, and the furnace door is closed. The furnace is evacuated until the vacuum degree in the melting furnace is 1Pa to 10Pa, and the heating and smelting is carried out to completely melt the raw materials into alloy liquid; the mass content of boron in the nickel-boron master alloy is 17%; the specific process of the heating and smelting As follows: heat up until the raw material starts to melt, fill it with argon until the vacuum degree is -0.04MPa~-0.02MPa, then heat up until the raw material is completely melted, then raise the temperature to 1700°C and keep it for 12 minutes;

Step 3. Pour the alloy liquid obtained in step 2 into the tundish preheated to 1100°C of the vacuum induction melting gas atomization powder making equipment, and flow out to the atomization chamber along the guide tube at the bottom of the tundish, and then to the High-pressure, high-speed argon gas is introduced into the atomization chamber, and the alloy liquid flowing out from the guide tube is atomized and dispersed into tiny droplets in the atomization chamber under the action of high-pressure argon gas flow, and then falls and cools to form alloy powder. The powder is classified and screened to obtain cobalt-chromium-nickel-tungsten alloy solder powder with a chemical composition of Co-20Cr-18Ni-4.5W-9Si-1.0B-0.4C; the diameter of the draft tube is 6 mm; the argon The inlet pressure is 3.5 MPa; the yield of -100 mesh powder in the cobalt-chromium-nickel-tungsten alloy solder powder is 90%.

After testing, the mass content of oxygen in the chromium-nickel-tungsten alloy solder powder prepared in this embodiment is 0.038%, the mass content of sulfur is 0.011%, the mass content of phosphorus is 0.012%, the mass content of aluminum is 0.021%, and the mass content of titanium is 0.011%. The mass content is 0.021%, and the mass content of other impurities is 0.21%, indicating that the quality of the chromium-nickel-tungsten alloy solder powder is uniform, the total amount of impurities and oxygen content are low, the process performance is superior, and it fully meets the needs of high-quality cobalt in various application fields. Technical requirements for chromium-nickel-tungsten alloy solder powder.

Example 4

The difference between this example and Example 3 lies in that the chemical composition of the cobalt-chromium-nickel-tungsten alloy solder powder in this example is Co-18Cr-16Ni-3.5W-7Si-0.6B-0.4C.

The above descriptions are only preferred embodiments of the present invention, and do not limit the present invention in any way. All simple modifications, changes and equivalent changes made to the above embodiments according to the technical essence of the invention still belong to the protection scope of the technical solution of the invention.

Claims (6)

1. A preparation method of cobalt-chromium-nickel-tungsten alloy brazing filler metal powder is characterized by comprising the following steps:

step one, placing a magnesium oxide crucible in an induction melting coil, filling joints of the magnesium oxide crucible by adopting magnesia sand and water glass, and then heating the filled magnesium oxide crucible to remove moisture;

step two, uniformly mixing raw materials of an electrodeposited cobalt plate, an electrolytic nickel plate, electrolytic chromium, a sintered tungsten bar, high-purity silicon particles, a nickel-boron intermediate alloy and high-purity carbon, adding the mixture into the magnesium oxide crucible heated and dehumidified in the step one, then putting the mixture into a smelting furnace of vacuum induction smelting gas atomization powder making equipment, closing a furnace door, vacuumizing the smelting furnace until the vacuum degree is 1-10 Pa, and then heating and smelting to completely melt the raw materials into an alloy liquid; the specific process of heating and smelting is as follows: heating to raise the temperature until the raw materials begin to melt, filling argon to the vacuum degree of-0.04 MPa to-0.02 MPa, then heating to raise the temperature until the raw materials are completely melted, raising the temperature to 1600-1700 ℃ and preserving the heat for 10-15 min;

and step three, pouring the alloy liquid obtained in the step two into a tundish of a vacuum induction melting gas atomization powder making device, enabling the alloy liquid to flow out to an atomization chamber along a guide pipe at the bottom of the tundish, introducing high-pressure argon gas into the atomization chamber, atomizing the alloy liquid flowing out of the guide pipe in the atomization chamber under the action of high-pressure argon gas flow to disperse into tiny liquid drops, then enabling the tiny liquid drops to fall down and be cooled to form alloy powder, and carrying out grading screening on the alloy powder to obtain the cobalt-chromium-nickel-tungsten alloy brazing filler metal powder.

2. The method for preparing the cobalt-chromium-nickel-tungsten alloy solder powder as claimed in claim 1, wherein the temperature for heating and dehumidifying in the step one is 900-1000 ℃ and the time is 8-10 h.

3. The method for preparing the cobalt-chromium-nickel-tungsten alloy brazing filler metal powder as claimed in claim 1, wherein in the second step, the mark of the electrodeposited cobalt plate is Co998, the mark of the electrolytic nickel plate is Ni9996, the mark of the electrolytic chromium plate is JCr99-A, the mark of the sintered tungsten bar is W-1, the mark of the high-purity silicon particles is Si-2, and the high-purity carbon is a carbon spectrum electrode.

4. The method for preparing the cobalt-chromium-nickel-tungsten alloy brazing filler metal powder according to claim 1, wherein the tundish in the third step is preheated to 1000-1100 ℃ before the alloy liquid is poured into the tundish, and the diameter of the flow guide pipe is 4-6 mm.

5. The method for preparing the cobalt-chromium-nickel-tungsten alloy brazing filler metal powder according to claim 1, wherein the introducing pressure of the high-pressure argon in the step three is 2.5MPa to 3.5 MPa.

6. The method for preparing the cobalt-chromium-nickel-tungsten alloy solder powder according to claim 1, wherein the mass content of cobalt in the cobalt-chromium-nickel-tungsten alloy solder powder in the step three is 47.0-54.5%, the mass content of chromium is 18.0-20.0%, the mass content of nickel is 16.0-18.0%, the mass content of tungsten is 3.5-4.5%, the mass content of silicon is 7.0-9.0%, the mass content of boron is 0.6-1.0%, the mass content of carbon is 0.1-0.4%, the mass content of oxygen is less than 0.05%, the mass content of sulfur is less than 0.02%, the mass content of phosphorus is less than 0.02%, the mass content of aluminum is less than 0.05%, the mass content of titanium is less than 0.05%, and the mass content of other impurities is less than 0.25%.