阅读说明：本技术 一种锆及锆合金大规格薄壁管材的制备方法 (Preparation method of zirconium and zirconium alloy large-specification thin-walled tube ) 是由 李新意 田航 周莹 张建军 周军 吴方奇 曹康琪 晁文辉 牟志军 于 2021-06-23 设计创作，主要内容包括：本发明公开了一种锆及锆合金大规格薄壁管材的制备方法,该方法包括：一、将锆及锆合金锻造棒坯分切或分切后淬火得到锭坯,经机加工得到待挤压锭坯；二、待挤压锭坯润滑后加热挤压得到挤压管坯；三、挤压管坯经表面处理后强力旋压得到锆及锆合金旋压件；步骤四、锆及锆合金旋压件经表面处理后进行退火；五、将经退火后的锆及锆合金旋压件依次重复强力旋压、表面处理和退火,得到锆及锆合金大规格薄壁管材。本发明将热挤压与旋压相结合,在保证挤压管坯高精度的同时快速减薄,克服了常规轧制工艺繁冗的难题,实现了锆及锆合金大规格薄壁管材的制备,满足了核电站用锆合金结构件性能要求。(The invention discloses a preparation method of a zirconium and zirconium alloy large-specification thin-walled tube, which comprises the following steps: firstly, cutting or quenching a zirconium and zirconium alloy forging bar blank to obtain an ingot blank, and machining to obtain an ingot blank to be extruded; secondly, heating and extruding the lubricated extruded ingot blank to obtain an extruded tube blank; thirdly, performing surface treatment on the extruded tube blank, and performing powerful spinning to obtain a zirconium and zirconium alloy spinning part; step four, annealing the zirconium and zirconium alloy spinning piece after surface treatment; and fifthly, repeating the powerful spinning, the surface treatment and the annealing of the annealed zirconium and zirconium alloy spinning piece in sequence to obtain the zirconium and zirconium alloy large-specification thin-walled tube. The invention combines hot extrusion and spinning, ensures high precision of the extruded tube blank and simultaneously quickly thins the extruded tube blank, overcomes the problem of redundancy of the conventional rolling process, realizes the preparation of the zirconium and zirconium alloy large-specification thin-walled tube, and meets the performance requirement of the zirconium alloy structural member for the nuclear power station.)

1. A preparation method of a zirconium and zirconium alloy large-specification thin-walled tube is characterized by comprising the following steps:

step one, slitting zirconium and zirconium alloy forging bar blanks to obtain ingot blanks, or slitting zirconium and zirconium alloy forging bar blanks, quenching, carrying out solution treatment to obtain ingot blanks, and then machining the ingot blanks to obtain ingot blanks to be extruded;

step two, lubricating the ingot blank to be extruded obtained in the step one, and then heating and extruding to obtain an extruded tube blank;

step three, performing surface treatment on the extruded tube blank obtained in the step two, and then performing powerful spinning to obtain a zirconium and zirconium alloy spinning part;

step four, annealing the zirconium and zirconium alloy spun parts obtained in the step three after surface treatment;

step five, sequentially repeating the powerful spinning process in the step three, the surface treatment process in the step four and the annealing process of the zirconium and zirconium alloy spinning part annealed in the step four until the processing times of the corresponding processes are 1-3 times to obtain the zirconium and zirconium alloy large-size thin-wall pipe; the outer diameter of the zirconium and zirconium alloy large-specification thin-walled tube is 50 mm-200 mm, and the wall thickness is 0.5 mm-5 mm.

2. The preparation method of the zirconium and zirconium alloy large-size thin-walled tube material as claimed in claim 1, wherein the quenching temperature in the first step is 1000-1070 ℃, the holding time is 1-2 h, the quenching transfer time is not more than 60s, the quenching medium is water, the water temperature before quenching is not more than 40 ℃, and the volume ratio of the medium used for quenching to the quenching blank is not less than 20: 1.

3. the method for preparing the zirconium and zirconium alloy large-size thin-walled tube according to claim 1, wherein the lubricating mode in the second step is brush coating or infiltrating of a lubricant, and the thickness of the lubricant on the surface of the ingot blank to be extruded after lubrication is 0.05mm to 0.2 mm; or the lubricating mode in the step two is glass lubricating: firstly, brushing an anti-oxidation coating on the surface of an ingot blank to be extruded, then rolling and coating glass powder, and placing the glass powder on the conical surface of an extrusion die for lubrication; or the lubricating mode in the step two is copper clad lubrication, and the inner surface and the outer surface of the ingot blank to be extruded are completely coated by a red copper sheet with the thickness of 0.8 mm-1.2 mm.

4. The method for preparing the zirconium and zirconium alloy large-size thin-walled tube according to claim 1, wherein the extrusion temperature in the second step is 600-840 ℃, the extrusion speed is 3-50 mm/s, and the extrusion ratio is 5-30.

5. The method for preparing the zirconium and zirconium alloy large-size thin-walled tube according to claim 1, wherein the ratio of the diameter to the wall thickness of the extruded tube blank in the second step is more than 8.

6. The method for preparing the zirconium and zirconium alloy large-size thin-walled tube according to claim 1, wherein the surface treatment in the third step is as follows: firstly, machining or polishing the inner surface and the outer surface of an extruded tube blank, and then carrying out acid pickling; the removal amount of machining or polishing is 0.5 mm-2 mm, the wall thickness deviation of the extruded tube blank after machining or polishing is not more than 0.2mm, and the pickling solution adopted by pickling is HNO₃The solution and HF solution, and the removing amount of the acid washing is 0.05 mm-0.2 mm.

7. The method for preparing the zirconium and zirconium alloy large-size thin-walled tube according to claim 1, wherein the deformation of the forced spinning in the third step is 15-40%, the deformation of the forced spinning in the third step is 2-4, and the total deformation of the forced spinning is 40-80%.

8. The method for preparing the zirconium and zirconium alloy large-size thin-walled tube according to claim 1, wherein the surface treatment in the fourth step is as follows: polishing the inner surface and the outer surface of the zirconium and zirconium alloy spinning part, and then pickling; the removal amount of the polishing is 0.05 mm-0.1 mm, and the pickling solution adopted by the pickling is HNO₃The solution and HF solution, and the removing amount of the acid washing is 0.02 mm-0.1 mm.

9. The method for preparing large-sized thin-walled tube of zirconium and zirconium alloy according to claim 1, wherein the annealing in the fourth step is vertical vacuum annealing at 400-700 ℃ under a vacuum degree of less than 1 x 10^-3Pa, and the heat preservation time is 1-3 h.

Technical Field

The invention belongs to the technical field of material forming, and particularly relates to a preparation method of a zirconium and zirconium alloy large-size thin-walled tube.

Background

Zirconium and zirconium alloys have good processability and very low thermal neutron absorption cross sections and have been the first choice materials for nuclear reactor cladding tubes and structural components. Meanwhile, because of the excellent acid-base corrosion resistance, zirconium and zirconium alloy play an important role as corrosion-resistant parts in the chemical industry. The thin-walled tube generally refers to a tube with the diameter/wall thickness ratio of more than 20, and the zirconium and zirconium alloy large-size thin-walled tube is mainly used for structural members in nuclear reactors, such as element boxes, pressure tubes, calandria and the like, and can also be used for radiation-resistant and corrosion-resistant pipelines in spent fuel post-treatment equipment. This requires that the zirconium and zirconium alloy large-sized thin-walled tube have uniform structure, stable mechanical properties and extremely high dimensional accuracy.

The preparation method of the large-size thin wall of zirconium and zirconium alloy mainly comprises plate coil welding, extrusion, multi-pass rolling and the like. Although the thin plate welding mode is low in cost, the welding seam is in an as-cast structure during welding, so that the corrosion resistance and the mechanical property of the thin plate welding mode are both improved, and the thin plate welding mode can only be used in low-pressure environments such as pressurized water reactor calandria and the like. The patent with publication number CN110877186A discloses a large-specification zirconium alloy thin-wall tube and a manufacturing method thereof, the large-specification zirconium alloy thin-wall tube is prepared by adopting extrusion and 5-pass rolling and annealing, and the high-precision thin-wall tube with diameter phi of 73mm multiplied by 1mm multiplied by 1540mm is obtained, however, because zirconium alloy is close-packed hexagonal metal, the open sliding system is less, the requirements on a cold rolling tool and a cold rolling die are extremely high, 5 sets of rolling pass and core rods need to be customized for implementing the patent, the high-precision thin-wall zirconium alloy tube can be rolled by multiple times of optimization and debugging, the input tool cost is high, the debugging time is long, and when the specification of the tube is changed, a plurality of sets of pass and core rods need to be customized and debugged again.

The zirconium and zirconium alloy large-specification thin-walled tube has various specifications, the demand of each specification is large, localization of the zirconium and zirconium alloy thin-walled tubes with various specifications is urgently needed, and meanwhile, the manufacturing cost is reduced.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a preparation method of a zirconium and zirconium alloy large-specification thin-walled tube aiming at the defects of the prior art. The method combines hot extrusion and spinning, combines corresponding surface treatment and annealing schedules, quickly reduces the wall thickness of the extruded tube blank while ensuring high precision of the extruded tube blank, overcomes the problem of complicated conventional rolling process, realizes the preparation of the zirconium and zirconium alloy large-specification thin-walled tube, and the prepared zirconium and zirconium alloy large-specification thin-walled tube has good surface quality, high dimensional precision, uniform microstructure and stable mechanical property, and meets the performance requirements of zirconium alloy structural members for nuclear power plants.

In order to solve the technical problems, the invention adopts the technical scheme that: a preparation method of a zirconium and zirconium alloy large-specification thin-walled tube is characterized by comprising the following steps:

step one, slitting zirconium and zirconium alloy forging bar blanks to obtain ingot blanks, or slitting zirconium and zirconium alloy forging bar blanks, quenching, carrying out solution treatment to obtain ingot blanks, and then machining the ingot blanks to obtain ingot blanks to be extruded;

step two, lubricating the ingot blank to be extruded obtained in the step one, and then heating and extruding to obtain an extruded tube blank;

step three, performing surface treatment on the extruded tube blank obtained in the step two, and then performing powerful spinning to obtain a zirconium and zirconium alloy spinning part;

step four, annealing the zirconium and zirconium alloy spun parts obtained in the step three after surface treatment;

step five, sequentially repeating the powerful spinning process in the step three, the surface treatment process in the step four and the annealing process of the zirconium and zirconium alloy spinning part annealed in the step four until the processing times of the corresponding processes are 1-3 times to obtain the zirconium and zirconium alloy large-size thin-wall pipe; the outer diameter of the zirconium and zirconium alloy large-specification thin-walled tube is 50 mm-200 mm, and the wall thickness is 0.5 mm-5 mm.

The method comprises the steps of slitting a zirconium and zirconium alloy forging bar blank (the civil zirconium and zirconium alloy pipe does not need solution treatment) or carrying out solution treatment after slitting to obtain an ingot blank, then carrying out machining such as peeling, drilling and chamfering to obtain an ingot blank to be extruded, lubricating the ingot blank to be extruded, heating and extruding, carrying out surface treatment, then carrying out powerful spinning thinning, surface treatment and annealing, and repeating the powerful spinning, the surface treatment and the annealing to obtain the zirconium and zirconium alloy large-size thin-wall pipe.

The invention combines hot extrusion and spinning, firstly adopts hot extrusion combined with surface treatment to prepare a high-precision extruded tube blank, then adopts powerful spinning to reduce the wall thickness and repeat the spinning process to obtain the zirconium and zirconium alloy large-specification thin-wall tube, greatly shortens the process flow, improves the preparation efficiency, overcomes the problem of complex process caused by customizing a plurality of sets of hole patterns and core rods with special curves and carrying out multiple optimization and verification in the conventional rolling, has better universality of the core rod adopted by the powerful spinning, can obtain different outer diameters and wall thicknesses only by customizing one spinning core rod for the zirconium and zirconium alloy thin-wall tubes with the same inner diameter, obviously reduces the cost of a tool and a die and the debugging period, and reduces the development cost for preparing the zirconium and zirconium alloy thin-wall tubes with different specifications.

Meanwhile, the invention adopts quenching solution treatment after slitting, machining and lubricating processes to ensure the smooth progress of hot extrusion and powerful spinning processes, combines surface treatment after extrusion to remove surface defects, improves the dimensional accuracy of an extruded tube blank, removes surface defects by surface treatment after powerful spinning, improves the surface cleanliness, and adopts an annealing process to realize the preparation of the zirconium and zirconium alloy large-specification thin-walled tube, and the prepared zirconium and zirconium alloy large-specification thin-walled tube has good surface quality, high dimensional accuracy, uniform microstructure and stable mechanical property, thereby being suitable for the production requirements of the zirconium and zirconium alloy large-specification thin-walled tube in small batch and in multiple specifications.

The preparation method of the zirconium and zirconium alloy large-specification thin-walled tube is characterized in that in the step one, the quenching temperature is 1000-1070 ℃, the heat preservation time is 1-2 h, the quenching transfer time is not more than 60s, the quenching medium is water, the water temperature before quenching is not more than 40 ℃, and the volume ratio of the medium used for quenching to the quenching blank is not less than 20: 1. the optimized quenching parameters ensure that the second phase in the zirconium alloy is fully dissolved in the zirconium alloy matrix, the optimized quenching transfer time, quenching medium and water temperature before quenching ensure the rapid cooling of the ingot blank, further promote the alloy elements to be dissolved in the zirconium alloy matrix, are favorable for improving the structure of the ingot blank to be extruded, and are suitable for preparing high-grade zirconium alloy such as nuclear-grade zirconium alloy.

The preparation method of the zirconium and zirconium alloy large-specification thin-walled tube is characterized in that the lubricating mode in the step two is brushing or infiltrating a lubricant, and the thickness of the lubricant on the surface of the ingot blank to be extruded after lubrication is 0.05-0.2 mm; or the lubricating mode in the step two is glass lubricating: firstly, brushing an anti-oxidation coating on the surface of an ingot blank to be extruded, then rolling and coating glass powder, and placing the glass powder on the conical surface of an extrusion die for lubrication; or the lubricating mode in the step two is copper clad lubrication, and the inner surface and the outer surface of the ingot blank to be extruded are completely coated by a red copper sheet with the thickness of 0.8 mm-1.2 mm.

The mode of brushing or infiltrating the lubricant and the thickness of the lubricant are optimized, so that the lubricating effect during extrusion is improved, and the surface quality of the extruded tube blank is ensured; the optimized glass is lubricated, so that hydrogen absorption of the zirconium alloy in the extrusion high-temperature heating process is effectively avoided; the optimized copper clad lubrication and the thickness of the red copper sheet ensure that the copper sheet is not broken in the extrusion process, have good lubricity and simultaneously give consideration to the economy.

The preparation method of the zirconium and zirconium alloy large-specification thin-walled tube is characterized in that in the second step, the extrusion temperature is 600-840 ℃, the extrusion speed is 3-50 mm/s, and the extrusion ratio is 5-30. Preferably, a low-temperature slow extrusion mode is adopted, so that a uniformly dispersed second phase can be obtained in the structure of the extruded tube blank, the corrosion performance of the zirconium and zirconium alloy tube is enhanced, and the performance of the zirconium and zirconium alloy large-size thin-walled tube is ensured.

The preparation method of the zirconium and zirconium alloy large-specification thin-walled tube is characterized in that the ratio of the diameter to the wall thickness of the extruded tube blank in the second step is greater than 8. The optimal selection condition ensures the generation of the zirconium and zirconium alloy large-specification thin-walled tube, is beneficial to improving the structure uniformity of the extruded tube blank and reduces the deformation of subsequent powerful spinning.

The preparation method of the zirconium and zirconium alloy large-specification thin-walled tube is characterized in that the surface treatment mode in the third step is as follows: firstly, machining or polishing the inner surface and the outer surface of an extruded tube blank, and then carrying out acid pickling; the removal amount of machining or polishing is 0.5 mm-2 mm, the wall thickness deviation of the extruded tube blank after machining or polishing is not more than 0.2mm, and the pickling solution adopted by pickling is HNO₃The solution and HF solution, and the removing amount of the acid washing is 0.05 mm-0.2 mm. By the optimized process and parameters, oxide skin and extrusion defects on the surface of the extruded tube blank are thoroughly removed, and the extruded tube blank with high dimensional precision and smooth surface is obtained.

The preparation method of the zirconium and zirconium alloy large-specification thin-walled tube is characterized in that in the third step, the pass deformation amount of the powerful spinning is 15% -40%, the pass deformation amount is 2-4 times, and the total deformation amount of the powerful spinning is 40% -80%. The optimized parameters of the powerful spinning ensure the full deformation of the extruded tube blank after surface treatment, improve the microstructure uniformity of the zirconium and zirconium alloy spinning piece, shorten the powerful spinning process and improve the efficiency of the powerful spinning.

The preparation method of the zirconium and zirconium alloy large-specification thin-walled tube is characterized in that the surface treatment mode in the fourth step is as follows: polishing the inner surface and the outer surface of the zirconium and zirconium alloy spinning part, and then pickling; the removal amount of the polishing is 0.05 mm-0.1 mm, and the pickling solution adopted by the pickling is HNO₃The solution and HF solution, and the removing amount of the acid washing is 0.02 mm-0.1 mm. The surface of a zirconium and zirconium alloy spinning part obtained by powerful spinning usually has slight spinning patterns, the defects of the spinning patterns are effectively removed by the optimized surface treatment process, the smooth proceeding of the subsequent processing process is ensured, and the surface quality of the product is improved.

The preparation method of the zirconium and zirconium alloy large-specification thin-walled tube is characterized in that the annealing mode in the fourth step is vertical vacuum annealing, the temperature of the vertical vacuum annealing is 400-700 ℃, and the vacuum degree value is less than 1 multiplied by 10^-3Pa, and the heat preservation time is 1-3 h. The vertical vacuum annealing mode and the corresponding process parameters are optimized, so that the structural uniformity of the zirconium and zirconium alloy large-size thin-walled tube is further improved, the plasticity and the corrosion resistance of the tube are effectively improved, and the straightness and the roundness of the product are ensured; if necessary, the zirconium and zirconium alloy spinning piece after surface treatment is subjected to counterweight at the bottom and then annealed so as to correct the straightness of the annealed workpiece.

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

1. the invention combines hot extrusion and spinning, combines corresponding surface treatment and annealing system, rapidly reduces the wall thickness while ensuring the high precision of the extruded tube blank, overcomes the difficult problem of redundant conventional rolling process, realizes the preparation of the zirconium and zirconium alloy large-specification thin-walled tube, and the prepared zirconium and zirconium alloy large-specification thin-walled tube has good surface quality, high dimensional precision, uniform microstructure and stable mechanical property, and meets the performance requirement of the zirconium alloy structural member for the nuclear power station.

2. The method can flexibly produce the zirconium and zirconium alloy large-specification thin-walled tubes with different outer diameters according to actual requirements, obviously shortens the preparation process of the zirconium and zirconium alloy large-specification thin-walled tubes, reduces the development and production cost, and is suitable for the requirements of multi-specification and small-batch production of the zirconium and zirconium alloy large-specification thin-walled tubes.

3. The zirconium and zirconium alloy large-specification thin-walled tube with the outer diameter of 50-200 mm and the wall thickness of 0.5-5 mm is prepared by the method.

The technical solution of the present invention is further described in detail by the accompanying drawings and examples.

Drawings

FIG. 1 is a metallographic structure diagram of a Zr-4 alloy thin-walled tube prepared in example 2 of the present invention.

Detailed Description

Example 1

The embodiment comprises the following steps:

step one, sawing an industrial pure zirconium R60702 forging bar blank to obtain an ingot blank, and then peeling, drilling and chamfering the ingot blank to obtain an ingot blank to be extruded with the specification of phi 216mm multiplied by 82mm multiplied by 450mm (external diameter multiplied by wall thickness multiplied by length);

step two, completely coating the inner surface and the outer surface of the ingot blank to be extruded obtained in the step one by using a red copper sheet with the thickness of 0.8 mm-1.2 mm, heating to 700 ℃, and extruding at the extrusion speed of 50mm/s and the extrusion ratio of 30 to obtain an extruded tube blank; the specification of the extruded tube blank is phi 61mm multiplied by 7mm multiplied by Lmm (outer diameter multiplied by wall thickness multiplied by length);

step three, performing acid washing on the extruded pipe blank obtained in the step two to remove copper skin, performing surface treatment to remove surface defects, and performing powerful spinning to obtain an industrial pure zirconium R60702 spun piece with the specification of phi 51.5mm multiplied by 1.2mm multiplied by Lmm (outer diameter multiplied by wall thickness multiplied by length); the surface treatment mode is as follows: polishing the inner and outer surfaces of the extruded tube blank to remove 0.1mm of polishing, wherein the wall thickness deviation of the extruded tube blank after polishing is not more than 0.2mm, and then pickling with HNO₃The solution and the HF solution, and the removal amount of the acid washing is 0.05 mm;

the pass deformation of the powerful spinning is 25% -30%, the pass deformation is 3 times, and the total deformation of the powerful spinning is 80%;

step four, the industrial pure zirconium R60702 spun piece obtained in the step four is subjected to acid cleaning after the inner and outer surfaces are polished, the polishing removal amount of the inner and outer surfaces is 0.05mm, and the acid cleaning solution adopted in the acid cleaning is HNO₃The solution and HF solution, the removal amount of acid washing is 0.02mm, and then the acid-washed industrial pure zirconium R60702 spinning part is vertically hung for vertical vacuum annealing; the temperature of the vertical vacuum annealing is 700 ℃, and the numerical value of the vacuum degree is less than 1 multiplied by 10^-3Pa, and the heat preservation time is 1 h;

fifthly, sequentially repeating the powerful spinning process in the third step, the surface treatment process and the annealing process for 1 time on the industrial pure zirconium R60702 spinning part subjected to vertical vacuum annealing in the fourth step to obtain an industrial pure zirconium R60702 thin-wall pipe with the specification of phi 50mm multiplied by 0.5mm multiplied by (3000-5000) mm (outer diameter multiplied by wall thickness multiplied by length); the pass deformation of the repeated power spinning is 18-25%, the pass is 2 times, the total deformation of the power spinning is 46%, and the pickling solution adopted by the repeated surface treatment process is HNO₃The solution and HF solution, the removing amount of acid cleaning is 0.05mm, the temperature of repeated vertical vacuum annealing is 700 ℃, and the vacuum degree value is less than 1 multiplied by 10^-3Pa, and the heat preservation time is 1 h.

Through detection, the surface roughness Ra of the industrial pure zirconium R60702 thin-wall pipe obtained by the embodiment is less than 0.5 mu m, the wall thickness deviation is less than 0.05mm, the grain size reaches 12 grades, the tensile strength is greater than 400MPa, the yield strength is greater than 300MPa, and the use requirement is completely met.

Example 2

The embodiment comprises the following steps:

step one, sawing a Zr-4 alloy forging bar blank, quenching, carrying out solution treatment to obtain an ingot blank, and then carrying out scalping, drilling and chamfering machining on the ingot blank to obtain an ingot blank to be extruded with the specification of phi 217mm multiplied by 72mm multiplied by 450mm (external diameter multiplied by wall thickness multiplied by length); the quenching temperature is 1070 ℃, the heat preservation time is 2 hours, the quenching transfer time is 20-30 s, the quenching medium is water, the water temperature before quenching is 25-30 ℃, and the volume ratio of the medium used for quenching to the quenched blank is 24: 1;

step two, coating a lubricant on the ingot blank to be extruded obtained in the step one for lubrication, wherein the thickness of the lubricant is 0.2mm, heating to 600 ℃, and extruding at the extrusion speed of 3mm/s and the extrusion ratio of 20 to obtain an extruded tube blank with the specification of phi 84mm multiplied by 7mm multiplied by Lmm (outer diameter multiplied by wall thickness multiplied by length);

step three, performing surface treatment on the extruded tube blank obtained in the step two to remove surface defects, and then performing powerful spinning to obtain a Zr-4 alloy spun part with the specification of phi 76mm multiplied by 2.5mm multiplied by Lmm (outer diameter multiplied by wall thickness multiplied by length); the surface treatment mode is as follows: polishing the inner surface and the outer surface of the extruded tube blank, wherein the removal amount of polishing is 0.5mm, the wall thickness deviation of the extruded tube blank after polishing is not more than 0.2mm, and the pickling solution adopted by pickling is HNO₃The solution and the HF solution, and the removal amount of the acid washing is 0.05 mm;

the deformation of the powerful spinning is 12-18%, the pass is 4 times, and the total deformation of the powerful spinning is 60%;

step four, polishing the inner surface and the outer surface of the Zr-4 alloy spinning part obtained in the step four, wherein the removal amount of the polishing of the inner surface and the outer surface is 0.1mm, and then pickling, wherein the pickling solution adopted by pickling is HNO₃The solution and the HF solution are mixed, the removal amount of acid washing is 0.05mm, and then the Zr-4 alloy spinning piece after acid washing is vertically suspended for vertical vacuum annealing; the temperature of the vertical vacuum annealing is 600 ℃, and the numerical value of the vacuum degree is less than 1 multiplied by 10^-3Pa, the heat preservation time is 1.5 h;

fifthly, sequentially repeating the powerful spinning process in the third step, the surface treatment process in the fourth step and the annealing process for 1 time on the Zr-4 alloy spinning part subjected to vertical vacuum annealing in the fourth step to obtain a Zr-4 alloy thin-wall pipe with the specification of phi 73mm multiplied by 1mm multiplied by (1000-3000) mm (external diameter multiplied by wall thickness multiplied by length); the pass deformation of the repeated power spinning is 20-30%, the pass deformation is 2 times, the total deformation of the power spinning is 50%, the removal amount of the polishing of the inner surface and the outer surface in the repeated surface treatment process is 0.1mm, and the pickling solution adopted by the pickling process is HNO₃Solution and HF solutionThe liquid composition, the removal amount of acid washing is 0.05mm, the temperature of repeated vertical vacuum annealing is 600 ℃, and the value of vacuum degree is less than 1 multiplied by 10^-3Pa, and the heat preservation time is 1.5 h.

In the second step of this embodiment, the ingot blank to be extruded can be soaked in the lubricant for lubrication.

The detection shows that the surface roughness Ra of the Zr-4 alloy thin-wall pipe obtained by the embodiment is less than 0.5 mu m, the wall thickness deviation is less than 0.04mm, the grain size reaches 12.5 grade, the tensile strength is more than 550MPa, the yield strength is more than 410MPa, and the use requirement is completely met.

Fig. 1 is a metallographic structure diagram of the Zr-4 alloy thin-walled tube prepared in this embodiment, and as can be seen from fig. 1, the Zr-4 alloy thin-walled tube has a uniform microstructure.

Example 3

The embodiment comprises the following steps:

step one, sawing a Zr-2.5Nb alloy forging bar blank, quenching, carrying out solution treatment to obtain an ingot blank, and then carrying out scalping, drilling and chamfering machining on the ingot blank to obtain an ingot blank to be extruded with the specification of phi 217mm multiplied by 56mm multiplied by 580mm (outer diameter multiplied by wall thickness multiplied by length); the quenching temperature is 1000 ℃, the heat preservation time is 1h, the quenching transfer time is 10 s-20 s, the quenching medium is water, the water temperature before quenching is 15-20 ℃, and the volume ratio of the medium used for quenching to the quenched blank is 30: 1;

step two, coating an anti-oxidation coating on the ingot blank to be extruded obtained in the step one, heating to 840 ℃, rolling and coating glass powder, placing the glass powder on the conical surface of an extrusion die for lubrication, and then extruding at 840 ℃ at the extrusion speed of 30mm/s and the extrusion ratio of 8 to obtain an extruded tube blank; the specification of the extruded tube blank is phi 122mm multiplied by 10mm multiplied by Lmm (outer diameter multiplied by wall thickness multiplied by length);

step three, performing surface treatment on the extruded tube blank obtained in the step two to remove surface defects, and then performing powerful spinning to obtain a Zr-2.5Nb alloy spinning part; the surface treatment mode is as follows: firstly, machining the inner surface bore hole and the outer surface of the extruded tube blank, wherein the removal amount of the inner surface bore hole is 1mm, the removal amount of the outer surface machining is 2mm, and controlling the extrusion after machiningThe deviation of the wall thickness of the tube blank is not more than 0.2mm, and then acid pickling is carried out, wherein the pickling solution adopted by the acid pickling is HNO₃The solution and the HF solution, and the removal amount of the acid washing is 0.2 mm;

the pass deformation of the powerful spinning is 15-25%, the pass is 2, the total deformation of the powerful spinning is 40%, and the specification of the Zr-2.5Nb alloy spinning piece is phi 113.5mm multiplied by 5.1mm multiplied by Lmm (outer diameter multiplied by wall thickness multiplied by length);

step four, polishing the outer surface of the Zr-2.5Nb alloy spinning part obtained in the step four, wherein the removal amount of the outer surface polishing is 0.1mm, and then carrying out acid pickling, wherein the pickling solution adopted by the acid pickling is HNO₃The method comprises the following steps of preparing a solution and an HF solution, wherein the removal amount of acid washing is 0.1mm, vertically suspending an acid-washed Zr-2.5Nb alloy spinning part for vertical vacuum annealing to obtain a Zr-2.5Nb alloy thin-walled tube with the specification of phi 113.4mm multiplied by 5mm multiplied by (1000-3000) mm (outer diameter multiplied by wall thickness multiplied by length); the temperature of the vertical vacuum annealing is 400 ℃, and the numerical value of the vacuum degree is less than 1 multiplied by 10^-3Pa, and the heat preservation time is 3 h.

Through detection, the surface roughness Ra of the Zr-2.5Nb alloy thin-wall pipe obtained in the embodiment is less than 0.5 mu m, the wall thickness deviation is less than 0.05mm, the grain size reaches 12 grades, the tensile strength is greater than 600MPa, the yield strength is greater than 450MPa, and the use requirement is completely met.

Example 4

The embodiment comprises the following steps:

step one, sawing a Zr-2 alloy forging bar blank, quenching, carrying out solution treatment to obtain an ingot blank, and then carrying out scalping, drilling and chamfering machining on the ingot blank to obtain an ingot blank to be extruded with the specification of phi 358mm multiplied by 80mm multiplied by 450mm (outer diameter multiplied by wall thickness multiplied by length); the quenching temperature is 1030 ℃, the heat preservation time is 1.5h, the quenching transfer time is 30-40 s, the quenching medium is water, the water temperature before quenching is 25-30 ℃, and the volume ratio of the medium used for quenching to the quenched blank is 35: 1;

step two, coating a lubricant on the ingot blank to be extruded obtained in the step one for lubrication, wherein the thickness of the lubricant is 0.05mm, then heating to 650 ℃, and extruding at the extrusion speed of 10mm/s and the extrusion ratio of 5 to obtain an extruded tube blank with the specification of phi 236mm multiplied by 21mm multiplied by Lmm (outer diameter multiplied by wall thickness multiplied by length);

step three, performing surface treatment on the extruded tube blank obtained in the step two to remove surface defects, and then performing powerful spinning to obtain a Zr-2 alloy spun part with the specification of phi 215mm multiplied by 10mm multiplied by Lmm (outer diameter multiplied by wall thickness multiplied by length); the surface treatment mode is as follows: removing 1mm of bore holes on the inner surface of the extruded tube blank, removing 1mm of machined outer surface of the extruded tube blank, ensuring that the wall thickness deviation of the extruded tube blank after machining is not more than 0.2mm, and then carrying out acid pickling, wherein the pickling solution adopted by the acid pickling is HNO₃The solution and the HF solution, and the removal amount of the acid washing is 0.05 mm;

the pass deformation of the powerful spinning is 25% -30%, the pass is 2, and the total deformation of the powerful spinning is 50%;

step four, polishing the inner surface and the outer surface of the Zr-2 alloy spinning part obtained in the step four, wherein the removal amount of the polishing of the inner surface and the outer surface is 0.08mm, and then pickling, wherein pickling solution adopted by pickling is HNO₃The solution and the HF solution are formed, the removal amount of acid washing is 0.02mm, and then the Zr-2 alloy spinning part after acid washing is vertically suspended for vertical vacuum annealing; the temperature of the vertical vacuum annealing is 580 ℃, and the numerical value of the vacuum degree is less than 1 multiplied by 10^-3Pa, and the heat preservation time is 2 h;

fifthly, sequentially repeating the powerful spinning process in the third step, the surface treatment process in the fourth step and the annealing process for 2 times on the Zr-2 alloy spinning part subjected to vertical vacuum annealing in the fourth step to obtain a Zr-2 alloy thin-wall pipe with the specification of phi 200mm multiplied by 2.4mm multiplied by (1000-3000) mm (outer diameter multiplied by wall thickness multiplied by length); the pass deformation of repeated two times of powerful spinning is 20-30%, the pass deformation is 2 times, the total deformation of the powerful spinning is 50%, the removal amount of polishing of the inner surface and the outer surface in the repeated surface treatment process is 0.1mm, and the pickling solution adopted by pickling is HNO₃The solution and HF solution, the removing amount of acid cleaning is 0.05mm, the temperature of repeated vertical vacuum annealing is 580 ℃, and the vacuum degree value is less than 1 multiplied by 10^-3Pa, and the heat preservation time is 2 h.

Through detection, the surface roughness Ra of the Zr-2 alloy thin-wall pipe obtained in the embodiment is less than 0.5 mu m, the wall thickness deviation is less than 0.05mm, the grain size reaches 13 grades, the tensile strength is more than 500MPa, the yield strength is more than 400MPa, and the use requirement is completely met.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention in any way. Any simple modification, change and equivalent changes of the above embodiments according to the technical essence of the invention are still within the protection scope of the technical solution of the invention.