High-temperature alloy bar surface treatment and pure scrap recovery method

Abstract

The invention discloses a high-temperature alloy bar surface treatment and pure scrap recovery method which comprises the following steps: S1, performing surface treatment on a high-temperature alloy bar in a pickling manner, and cleaning oxide skin and impurities on the surface layer of the bar; s2, the bar subjected to surface treatment in the step S1 is scalped through a lathe, and scraps generated in the scalping process are collected; s3, the scraps are crushed to a proper length; s4, the high-temperature alloy scraps crushed in the step S3 are put into a cleaning agent solution with a certain temperature and concentration to be cleaned for a proper time, and oil stains on the surfaces of the scraps are removed; s5, the high-temperature alloy scraps cleaned in the step S4 are put into pure water with the proper temperature and PH value to be rinsed for a proper time, and the cleaning agent on the surfaces of the scraps is removed; and S6, the high-temperature alloy scraps rinsed in the step S5 are dried. According to the method, the high-temperature alloy scraps are recycled through the bar surface treatment and scrap cleaning process, and the content of oxygen and nitrogen inclusions in the scraps can be effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of high-temperature alloy chip recovery, in particular to a high-temperature alloy bar surface treatment and pure chip recovery method. Background Art

[0002] Superalloys, composed of strategic metal elements such as nickel, cobalt, chromium, tungsten, and molybdenum, are widely used in gas turbines, nuclear power plants, ships, and thermal power generation, primarily as components such as turbine disks, rings, casings, shafts, and heat transfer tubes. These components are subjected to a variety of complex loads during service, including centrifugal forces from high-speed rotation, radial thermal stresses, and aerodynamic forces under high pressure. This places higher demands on the alloy's impurity and inclusion content. During the production process at superalloy smelters, 4% to 10% of scrap is generated, primarily from bar stock. Due to the high temperatures of bar stock processing, foreign matter such as asbestos and oxide layers adhere to the bar stock surface, resulting in poor scrap purity. Traditionally, this has been treated as downgraded material, resulting in a waste of metal resources. To meet the purity requirements of return material for superalloys, research on methods for recycling scrap is crucial.

[0003] Currently, traditional chip recycling processes in China include crushing, magnetic separation, alkaline washing, water rinsing, and drying. These steps can effectively remove oil stains, but they do not involve pre-cleaning the bar surface and do not fundamentally solve the problem of chip purity. The present invention, through reasonable bar surface treatment and chip recycling technology, can produce chips with higher purity. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for surface treatment of high-temperature alloy bars and recovery of pure chips. By adopting the process of bar surface treatment + chip cleaning, high-temperature alloy chips with clean composition and gas element (O, N) content less than 0.0010% can be obtained.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for surface treatment of high-temperature alloy bars and recovery of clean chips, specifically comprising the following steps:

[0006] S1. The high-temperature alloy rod is surface treated by pickling to remove the oxide scale and impurities on the surface of the rod;

[0007] S2, peeling the bar material after the surface treatment in S1 using a lathe, and collecting the scraps generated during the peeling process;

[0008] S3, crushing the chips to appropriate length;

[0009] S4. The high-temperature alloy chips crushed in S3 are placed in a cleaning solution of a certain temperature and concentration and cleaned for an appropriate time to remove oil stains on the surface of the chips;

[0010] S5. The high-temperature alloy chips cleaned in S4 are placed in pure water of appropriate temperature and pH value and rinsed for an appropriate time to remove the cleaning agent on the surface of the chips;

[0011] S6. Drying the high-temperature alloy chips rinsed in S5.

[0012] Preferably, the pickling method in S1 is to place the high-temperature alloy rod into a container containing a pickling solution for immersion, the pickling solution composition is hydrochloric acid: copper sulfate: water = (10±3)%: (5±2)%: (85±5)%, the pickling temperature is (20-40)°C, and the pickling time is (2-10)h.

[0013] Preferably, the length of the high-temperature alloy chips in S3 after crushing is in the range of (10 to 30) mm.

[0014] Preferably, the cleaning method in S4 is stirring or ultrasonic, the cleaning temperature is (20-50)°C, the cleaning agent concentration is (2%-10%), the cleaning agent composition is fatty alcohol polyoxyethylene ether AEO9: disodium ethylenediaminetetraacetic acid: potassium hydroxide: urea = (0.3±0.2)%: (1.5±1)%: (70±5)%: (2.5±2)%, and the cleaning time is (5-60) min.

[0015] Preferably, the pure water temperature in S5 is (30-70)°C, the pure water pH value is (7-9.2), and the rinsing time is (10-60) min.

[0016] Preferably, the drying temperature in S6 is (60-200)°C, and the drying time is (0.5-3)h.

[0017] The present invention effectively removes oxygen and nitrogen inclusions in the chips through rod surface treatment and chip cleaning. The chips are clean and the contents of oxygen and nitrogen in the gas elements are both less than 0.0010%, so they can be directly used as raw materials for smelting. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Surface quality of HT700T high-temperature alloy rod before and after surface treatment. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] like Figure 1As shown, the present invention provides a technical solution: a method for surface treatment of high-temperature alloy bars and recovery of pure chips, comprising the following steps:

[0021] S1. The high-temperature alloy rod is surface treated by pickling to remove the oxide scale and impurities on the surface of the rod;

[0022] S2, peeling the bar material after the surface treatment in S1 using a lathe, and collecting the scraps generated during the peeling process;

[0023] S3, crushing the chips to appropriate length;

[0024] S4. The high-temperature alloy chips crushed in S3 are placed in a cleaning solution of a certain temperature and concentration and cleaned for an appropriate time to remove oil stains on the surface of the chips;

[0025] S5. The high-temperature alloy chips cleaned in S4 are placed in pure water of appropriate temperature and pH value and rinsed for an appropriate time to remove the cleaning agent on the surface of the chips;

[0026] S6. Drying the high-temperature alloy chips rinsed in S5.

[0027] The pickling method in S1 is to place the high-temperature alloy rod into a container filled with a pickling solution for immersion. The pickling solution composition is hydrochloric acid: copper sulfate: water = (10±3)%: (5±2)%: (85±5)%, the pickling temperature is (20-40)°C, and the pickling time is (2-10)h.

[0028] The length of the S3 high-temperature alloy chips after crushing is in the range of (10-30) mm.

[0029] The cleaning method in S4 is stirring or ultrasonic, the cleaning temperature is (20-50)°C, the cleaning agent concentration is (2%-10%), and the cleaning agent composition is fatty alcohol polyoxyethylene ether AEO9: disodium ethylenediaminetetraacetic acid: potassium hydroxide: urea = (0.3±0.2)%: (1.5±1)%: (70±5)%: (2.5±2)%, and the cleaning time is (5-60) min.

[0030] The pure water temperature in S5 is (30-70)°C, the pure water pH value is (7-9.2), and the rinsing time is (10-60) min.

[0031] The drying temperature in S6 is (60-200)°C, and the drying time is (0.5-3)h.

[0032] Example

[0033] (1) Surface treatment of rods: Immerse a HT700T high-temperature alloy rod with a size of 350 × 820 mm and a weight of 624 kg in a container containing a pickling solution. The composition of the pickling solution is hydrochloric acid: copper sulfate: water = 10%: 5%: 85%. The pickling temperature is 25 ° C and the pickling time is 8 h.

[0034] (2) Chip collection: The bars after S1 surface treatment were peeled using a lathe, and 51 kg of HT700T chips generated during the peeling process were collected.

[0035] (3) Crushing: The collected 51 kg of scraps were crushed twice using a shredder to crush the scraps into flakes with a length of (10-15) mm.

[0036] (4) Cleaning: In a cleaning tank equipped with an ultrasonic generator, add 1 cubic meter of pure water at a temperature of 60°C, and add 20 kg of cleaning agent into the pure water. The cleaning agent composition is fatty alcohol polyoxyethylene ether AEO9: disodium ethylenediaminetetraacetic acid: potassium hydroxide: urea = 0.3%: 1.5%: 70%: 2.5%. Put the crushed HT700T chips into the cleaning tank and apply ultrasonic stirring for 40 minutes.

[0037] (5) Rinsing: Take out the cleaned scraps and place them in pure water with a temperature of 50°C and a pH of 7.1, and stir for 30 minutes.

[0038] (6) Drying: Place the rinsed scraps in a hot air circulation drying oven for drying at a temperature of 200°C for 2 hours.

[0039] Finally, HT700T chips with clean components and gas element oxygen and nitrogen contents less than 0.0010% were prepared; the carbon and sulfur (C, S) contents of the HT700T chips are shown in Table 1; the gas element (O, N) contents of the HT700T chips are shown in Table 2.

[0040] Table 1 Carbon and sulfur (C, S) content of HT700T chips

[0041] element C S HT700T before chip recycling 0.050 0.0005 HT700T scrap after recycling 0.051 0.0005 evaluate Clean ingredients Clean ingredients

[0042] Table 2 Content of gas elements (O, N) in HT700T chips

[0043] element O N HT700T chips 0.0005 0.0006

[0044] Comparative Example

[0045] (1) Chip collection: A HT700T bar with a size of Ø350×900mm and a weight of 705kg was peeled using a lathe, and 55kg of chips were collected during the peeling process.

[0046] (2) Crushing: 55 kg of HT700T scraps were crushed twice using a shredder to reduce the scraps into flakes with a length of (10-15) mm.

[0047] (3) Cleaning: In a cleaning tank equipped with an ultrasonic generator, add 1 cubic meter of pure water at a temperature of 60°C, and add 20 kg of cleaning agent into the pure water. The cleaning agent composition is fatty alcohol polyoxyethylene ether AEO9: disodium ethylenediaminetetraacetic acid: potassium hydroxide: urea = 0.3%: 1.5%: 70%: 2.5%. Put the crushed HT700T chips into the cleaning tank and apply ultrasonic stirring for 40 minutes.

[0048] (4) Rinse: Take out the cleaned scraps and place them in pure water with a temperature of 50°C and a pH of 7.1, and stir for 30 minutes.

[0049] (5) Drying: Place the rinsed HT700T chips in a hot air circulation drying oven for drying at a temperature of 200°C for 2 hours.

[0050] Finally, HT700T chips with clean components but gaseous element oxygen and nitrogen contents greater than 0.0010% were prepared; the carbon and sulfur (C, S) contents of the HT700T chips are shown in Table 3; the gaseous element (O, N) contents of the HT700T chips are shown in Table 4.

[0051] Table 3 Carbon and sulfur (C, S) content of HT700T chips

[0052] element C S HT700T before chip recycling 0.049 0.0005 HT700T scrap after recycling 0.050 0.0005 evaluate Clean ingredients Clean ingredients

[0053] Table 4 HT700T chip gas element (O, N) content

[0054] element O N HT700T chips 0.0011 0.0038

[0055] In summary, the present invention recycles high-temperature alloy chips by adopting the process of bar surface treatment + chip cleaning to prepare high-temperature alloy chips with clean components and gas element (O, N) content less than 0.0010%.

[0056] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for surface treatment of high temperature alloy bars and recovery of pure chips, characterized in that: The steps include: S1. The high-temperature alloy rod is surface treated by pickling to remove the oxide scale and impurities on the surface of the rod; S2, peeling the bar material after the surface treatment in S1 using a lathe, and collecting the scraps generated during the peeling process; S3, crushing the chips to appropriate length; S4. The high-temperature alloy chips crushed in S3 are placed in a cleaning solution of a certain temperature and concentration and cleaned for an appropriate time to remove oil stains on the surface of the chips; S5. The high-temperature alloy chips cleaned in S4 are placed in pure water of appropriate temperature and pH value and rinsed for an appropriate time to remove the cleaning agent on the surface of the chips; S6. Drying the high-temperature alloy chips rinsed in S5.

2. The method for surface treatment of high-temperature alloy bars and recovery of clean chips according to claim 1, characterized in that: The pickling method in S1 is to place the high-temperature alloy rod into a container filled with a pickling solution for immersion. The pickling solution composition is hydrochloric acid: copper sulfate: water = (10±3)%: (5±2)%: (85±5)%, the pickling temperature is (20-40)°C, and the pickling time is (2-10)h.

3. The method for surface treatment of high temperature alloy bars and recovery of clean chips according to claim 1, characterized in that: The length of the S3 high-temperature alloy chips after crushing is in the range of (10-30) mm.

4. The method for surface treatment of high-temperature alloy bars and recovery of clean chips according to claim 1, characterized in that: The cleaning method in S4 is stirring or ultrasonic, the cleaning temperature is (20-50)°C, the cleaning agent concentration is (2%-10%), and the cleaning agent composition is fatty alcohol polyoxyethylene ether AEO9: disodium ethylenediaminetetraacetic acid: potassium hydroxide: urea = (0.3±0.2)%: (1.5±1)%: (70±5)%: (2.5±2)%, and the cleaning time is (5-60) min.

5. The method for surface treatment of high temperature alloy bars and recovery of clean chips according to claim 1, characterized in that: The pure water temperature in S5 is (30-70)°C, the pure water pH value is (7-9.2), and the rinsing time is (10-60) min.

6. The method for surface treatment of high temperature alloy bars and recovery of clean chips according to claim 1, characterized in that: The drying temperature in S6 is (60-200)°C, and the drying time is (0.5-3)h.

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