阅读说明：本技术 一种镍基高温合金电极棒的制备方法 (Preparation method of nickel-based high-temperature alloy electrode bar ) 是由 唐洪奎 马宽 李安 王晨 宋嘉明 周晓明 梁书锦 赖运金 王庆相 于 2019-09-30 设计创作，主要内容包括：本发明公开了一种镍基高温合金电极棒的制备方法,包括：步骤1、将镍基高温合金原材,铸造成母合金棒；步骤2、将步骤1中得到的母合金棒在热等静压炉中,进行热等静压；步骤3、将步骤2中热等静压后的母合金棒置入真空或氩气保护热处理炉中进行热处理；步骤4、将步骤3中热处理后的母合金棒进行粗车,制备成半成品电极棒；步骤5、将步骤4中粗车后的半成品电极棒进行精车,得到合格的成品电极棒。采用热等静压处理母合金棒材,使母合金中的裂纹和小气孔缺陷消失,提高了合金致密度,避免了电极棒再高速旋转过程中裂纹扩展断裂或质量不均匀导致电极棒跳动。(The invention discloses a preparation method of a nickel-based superalloy electrode rod, which comprises the following steps: step 1, casting a nickel-based high-temperature alloy raw material into a master alloy rod; step 2, carrying out hot isostatic pressing on the master alloy rod obtained in the step 1 in a hot isostatic pressing furnace; step 3, placing the mother alloy rod subjected to hot isostatic pressing in the step 2 into a vacuum or argon protection heat treatment furnace for heat treatment; step 4, roughly turning the master alloy rod subjected to the heat treatment in the step 3 to prepare a semi-finished electrode rod; and 5, carrying out finish turning on the semi-finished electrode bar subjected to rough turning in the step 4 to obtain a qualified finished electrode bar. The hot isostatic pressing treatment is adopted for the master alloy bar, so that the defects of cracks and small air holes in the master alloy disappear, the alloy density is improved, and the electrode bar jumping caused by crack propagation fracture or uneven quality in the high-speed rotation process of the electrode bar is avoided.)

1. The preparation method of the nickel-based superalloy electrode rod is characterized by comprising the following steps:

step 1, casting a nickel-based high-temperature alloy raw material into a master alloy rod;

step 2, carrying out hot isostatic pressing on the master alloy rod obtained in the step 1 in a hot isostatic pressing furnace;

step 3, placing the mother alloy rod subjected to hot isostatic pressing in the step 2 into a vacuum or argon protection heat treatment furnace for heat treatment;

step 4, roughly turning the master alloy rod subjected to the heat treatment in the step 3 to prepare a semi-finished electrode rod;

and 5, carrying out finish turning on the semi-finished electrode bar subjected to rough turning in the step 4 to obtain a qualified finished electrode bar.

2. The method for preparing the nickel-based superalloy electrode rod according to claim 1, wherein the step 1 is specifically performed according to the following steps:

1.1, heating and melting a nickel-based high-temperature alloy raw material in a vacuum induction melting furnace, electromagnetically stirring for 30min to ensure that the alloy components are uniform, and casting a mother alloy bar rough blank with the size of phi 80 multiplied by 750 mm;

and step 1.2, carrying out electroslag remelting on the rough blank of the master alloy rod obtained in the step 1.1, and casting the rough blank into the master alloy rod with the size phi of 70 x 750 mm.

3. The preparation method of the nickel-based superalloy electrode rod according to claim 1, wherein the hot isostatic pressing in the step 2 is performed at 1050-1180 ℃, the pressure in a furnace is greater than 120Mpa, the temperature is maintained for 3 hours, and the electrode rod is cooled along with the furnace, so that microcracks and small-size air holes are closed, and the density of a master alloy rod is improved.

4. The preparation method of the nickel-based superalloy electrode rod according to claim 1, wherein the heat treatment temperature in the step 3 is 980-1170 ℃, the temperature is kept for 1-3 hours, and then the electrode rod is taken out and cooled in air to improve the alloy strength.

5. The method for preparing the nickel-based superalloy electrode rod according to claim 1, wherein the rough turning in the step 4 is performed to obtain the electrode rod with the size phi of 55 mm to 68 mm plus or minus 1mm, the length of 750mm plus or minus 5mm, the roughness of less than 6.3 μm, and the straightness of less than 0.5 mm.

6. The method for preparing the nickel-based superalloy electrode rod according to claim 1, wherein the size of the electrode rod finely turned in the step 5 is phi 55-68 ± 0.5mm, the length is 750 ± 5mm, the roughness is less than 1.6 μm, and the external circular runout is less than 0.1 mm.

Technical Field

The invention belongs to the technical field of metal material processing, and relates to a preparation method of a nickel-based high-temperature alloy electrode rod.

Background

The plasma rotating electrode powder making method is a powder making method which is used for making a consumable electrode rod by metal or alloy, wherein the end face of the consumable electrode rod is heated by plasma and melted into liquid, the liquid is thrown out and crushed into fine liquid drops through the centrifugal force generated by the high-speed rotation of the electrode rod, and the fine liquid drops are condensed into powder, and the powder making method is one of the main methods for preparing high-quality 3D printing spherical powder.

However, the powder required by 3D printing is fine powder (15-53 μm), and in order to improve the yield of the high-temperature alloy fine powder, the rotating speed of the electrode rod needs to reach 24000r/min or more, and at such a high rotating speed, the electrode rod is subjected to an extremely large centrifugal force, and if cracks or large-sized shrinkage holes exist in the electrode rod, the electrode rod rotating at a high speed is broken or bent, so that the equipment is damaged. Therefore, the requirements for internal defects of the electrode rod are very strict. The traditional preparation method of the high-temperature alloy electrode rod is to prepare the master alloy rod into the electrode rod through processes of hot rolling, straightening, heat treatment, machining and the like.

Disclosure of Invention

The invention provides a preparation method of a nickel-based high-temperature alloy electrode bar, which eliminates cracks and small-size shrinkage cavities in a master alloy through Hot Isostatic Pressing (HIP) treatment, improves the density of the alloy, ensures uniform components in the alloy through heat treatment and improves the strength of the alloy.

In order to achieve the purpose, the technical scheme adopted by the invention is that the preparation method of the nickel-based superalloy electrode rod is implemented according to the following steps:

step 1, casting a nickel-based high-temperature alloy raw material into a master alloy rod;

step 2, carrying out hot isostatic pressing on the master alloy rod obtained in the step 1 in a hot isostatic pressing furnace;

step 3, placing the mother alloy rod subjected to hot isostatic pressing in the step 2 into a vacuum or argon protection heat treatment furnace for heat treatment;

step 4, roughly turning the master alloy rod subjected to the heat treatment in the step 3 to prepare a semi-finished electrode rod;

and 5, carrying out finish turning on the semi-finished electrode bar subjected to rough turning in the step 4 to obtain a qualified finished electrode bar.

The step 1 is implemented according to the following steps:

1.1, heating and melting a nickel-based high-temperature alloy raw material in a vacuum induction melting furnace, electromagnetically stirring for 30min to ensure that the alloy components are uniform, and casting a mother alloy bar rough blank with the size of phi 80 multiplied by 750 mm;

step 1.2, carrying out electroslag remelting on the rough blank of the master alloy rod obtained in the step 1.1, and casting the rough blank into a master alloy rod with the size of phi 70 multiplied by 750 mm;

and (3) in the step 2, the hot isostatic pressing temperature is 1050-1180 ℃, the pressure in the furnace is more than 120Mpa, the temperature is kept for 3 hours, and the heat is cooled along with the furnace, so that microcracks and small-size air holes are closed, and the density of the master alloy bar is improved.

And 3, keeping the heat treatment temperature of 980-1170 ℃ for 1-3 hours, taking out, and cooling in air to improve the alloy strength.

In the step 4, the size of the roughly turned electrode bar is phi 55-68 +/-1 mm, the length is 750 +/-5 mm, the roughness is less than 6.3 mu m, and the straightness is less than 0.5 mm.

The size of the electrode rod finely turned in the step 5 is phi 55-68 +/-0.5 mm, the length is 750 +/-5 mm, the roughness is less than 1.6 mu m, and the excircle runout is less than 0.1 mm.

The invention has the beneficial effects that:

1. the invention abandons the hot rolling and straightening processes of the master alloy bar, avoids the cracking and oxidation of the master alloy in the hot rolling process, improves the yield of the electrode bar and reduces the processing cost of the electrode bar;

2. according to the invention, the hot isostatic pressing treatment is adopted for the master alloy bar, so that the defects of cracks and small air holes in the master alloy are eliminated, the alloy density is improved, and the electrode bar jumping caused by crack propagation fracture or uneven quality in the high-speed rotation process of the electrode bar is avoided;

3. the invention adopts heat treatment to improve the strength of the electrode bar and avoid the bending of the electrode bar in the high-speed rotation process;

4. according to the invention, the machining of the master alloy bar is divided into two steps, the oxide skin of the bar is removed in the first step of rough machining, and the turning in the second step of finish machining can be recycled, so that the production cost of the electrode bar is reduced.

Detailed Description

The present invention will be described in detail with reference to the following embodiments.

The invention relates to a preparation method of a nickel-based superalloy electrode bar, which is implemented by the following steps:

step 1, casting a nickel-based high-temperature alloy raw material into a master alloy rod;

step 2, carrying out hot isostatic pressing on the master alloy rod obtained in the step 1 in a hot isostatic pressing furnace;

step 3, placing the mother alloy rod subjected to hot isostatic pressing in the step 2 into a vacuum or argon protection heat treatment furnace for heat treatment;

step 4, roughly turning the master alloy rod subjected to the heat treatment in the step 3, removing oxide skin, and preparing a semi-finished electrode rod;

and 5, carrying out finish turning on the semi-finished electrode bar subjected to rough turning in the step 4 to obtain a qualified finished electrode bar.

The step 1 is implemented according to the following steps:

1.1, heating and melting a nickel-based high-temperature alloy raw material in a vacuum induction melting furnace, electromagnetically stirring for 30min to ensure that the alloy components are uniform, and casting a mother alloy bar rough blank with the size of phi 80 multiplied by 750 mm;

step 1.2, carrying out electroslag remelting on the rough blank of the master alloy rod obtained in the step 1.1, casting the rough blank into a master alloy rod with the size of phi 70 multiplied by 750mm, removing non-metal impurities in the master alloy rod, reducing impurity elements such as sulfur and phosphorus in the master alloy, and improving the purity of the master alloy;

and (3) in the step (2), the hot isostatic pressing temperature is 1050-1180 ℃, the pressure in the furnace is more than 120Mpa, the temperature is kept for 3 hours, the furnace is cooled, the microcracks and small-size air holes are closed, the density of the master alloy bar is improved, and the density of the alloy after the hot isostatic pressing is more than 99%.

And 3, keeping the heat treatment temperature of 980-1170 ℃ for 1-3 hours, taking out, and cooling in air to improve the alloy strength.

In the step 4, the size of the roughly turned electrode bar is phi 55-68 +/-1 mm, the length is 750 +/-5 mm, the roughness is less than 6.3 mu m, and the straightness is less than 0.5 mm.

The size of the electrode rod finely turned in the step 5 is phi 55-68 +/-0.5 mm, the length is 750 +/-5 mm, the roughness is less than 1.6 mu m, and the excircle runout is less than 0.1 mm.

The invention directly adopts the high-temperature alloy base metal subjected to secondary smelting to carry out hot isostatic pressing, abandons the hot rolling and straightening processes of the master alloy, improves the yield of the master alloy bar, simultaneously avoids the problem of hot rolling cracking of the master alloy, further improves the strength of the master alloy bar through heat treatment, and processes the bar to the required size of the electrode bar through rough turning and finish turning, so that the rotating speed of the electrode bar in the process of preparing powder by the plasma rotating electrode reaches over 24000r/min, the production efficiency is improved, and the cost of fine powder for 3D printing is reduced.