Production process of GH4169 alloy spring wire for nuclear power

Abstract

The invention discloses a production technology of a GH4169 alloy spring wire for nuclear power. The production technology comprises the following steps that S1, raw materials are prepared, wherein the raw materials comprise, by mass, 0%-0.08% of C, 17%-21% of Cr, 50%-55% of Ni, 2.8%-3.2% of Mo, 5.0%-5.5% of Nb, 0.4%-0.7% of AI, 0.70%-1.00% of Ti and the balance Fe; unavoidable impurities exist in the raw materials, and the impurities need to be controlled and treated according to the mass percent of Co: 0 to 0.04 percent, Mg: 0 to 0.01 percent, B: 0 to 0.006 percent, Si: 0 to 0.35 percent, Mn: 0 to 0.35 percent, P: 0 to 0.015 percent, S: 0 to 0.015 percent and Cu: 0 to 0.3 percent. The materials are mixed and subjected to vacuum induction melting and electroslag remelting treatment to form an alloy wire rod with the diameter being 8.0-10.0 mm; s2, peeling treatment is conducted, specifically, surface layer defects of the alloy wire rod in the step S1 are removed through a peeling machine; s3, coping treatment is conducted, specifically, the alloy wire rod treated in the step S2 is coped through a coping abrasive belt; the cooling mode can be optimized, the surface quality and the mechanical property of the spring wire are improved, and meanwhile pollution of halogen elements is avoided.

Description

TECHNICAL FIELD

[0001] The application relates to a production process of GH4169 alloy spring wire for nuclear power, and belongs to the technical field of high-temperature alloy precision wire processing. BACKGROUND

[0002] At present, the GH4169 alloy has become the core material of nuclear power spring due to excellent high-temperature strength, corrosion resistance and radiation resistance. However, the traditional production process has the following problems: the solid solution treatment is mostly water quenching or oil quenching, which leads to surface oxidation or carbonization, the roughness is greater than 1.6 mu m, and subsequent pickling treatment is needed, which causes halogen element pollution and affects the use of nuclear power; uneven cooling leads to large grain size fluctuation and tensile strength deviation of more than 100 MPa; surface repair is needed before aging, which increases the cost and affects the material consistency. SUMMARY

[0003] The technical problem to be solved by the application is to overcome the defects of the prior art and provide a production process of GH4169 alloy spring wire for nuclear power, which can optimize the cooling method, improve the surface quality and performance of the spring wire, and avoid halogen element pollution.

[0004] In order to solve the above technical problems, the technical scheme of the application is as follows: a production process of GH4169 alloy spring wire for nuclear power, comprising the following steps: S1, raw material preparation: the raw material is prepared according to the mass percentage of C: 0-0.08%, Cr: 17-21%, Ni: 50-55%, Mo: 2.8-3.2%, Nb: 5.0-5.5%, Al: 0.4-0.7%, Ti: 0.70-1.00% and the balance of Fe; The above materials are mixed for vacuum induction melting and electroslag remelting treatment to form an alloy rod with a diameter of 8.0-10.0 mm; S2, skinning treatment: the alloy rod in step S1 is removed from the surface layer defect by a skinning machine; S3, grinding treatment: the alloy rod after the treatment in step S2 is ground by a grinding belt; S4, drawing treatment: the alloy rod after the treatment in step S3 is drawn into an alloy wire by a drawing die; S5, solid solution treatment: the alloy wire after the treatment in step S4 is placed in a vacuum air quenching furnace, and is kept at 945-965 DEG C for 30 min, and then argon gas is input into the vacuum air quenching furnace for gas quenching treatment; S6, spring making: the alloy wire after the treatment in step S5 is wound and formed into a spring by a spring machine; S7, aging treatment: the shaped spring in step S6 is placed in an aging furnace, and is kept at 710-730 DEG C for 8h, then is cooled to 610-630 DEG C at a speed of 50-60 DEG C / h, and is kept at 610-630 DEG C for 8h again, and finally is air cooled.

[0005] Further, the removal depth in step S2 is 0.3-0.5mm.

[0006] Further, the grit size of the grinding belt in step S3 is 100-400#, and the grinding speed is 5-20m / min.

[0007] Further, the drawing die material in step S4 is polycrystalline diamond, and the drawing speed is 10-30m / min.

[0008] Further, the drawing die in step S4 needs to be added with water-based drawing oil with a PH value of 8.5-9.0.

[0009] Further, the argon gas purity in step S5 is greater than or equal to 99.999%, and the argon gas pressure is 6.0-7.0bar.

[0010] Further, the water-based drawing oil further comprises conventional extreme pressure additives, conventional antioxidants and conventional rust inhibitors.

[0011] By adopting the technical scheme, the present application has the following beneficial effects: 1. In the present application, the oil drawing and argon quenching process are adopted to replace the traditional water-oil quenching, so that the bright state delivery is realized, and subsequent pickling is not needed, and the process is environmentally friendly and efficient.

[0012] 2. In the present application, the argon cooling has no quenching time difference, the performance is uniform, the grain size is stable at 8.0 or above, the tensile strength fluctuation range is reduced by 60%, and the material consistency is significantly improved.

[0013] 3. In the present application, the whole process is clean production, and there is no pickling residue on the surface, so that the C1 induced stress corrosion is avoided, and the halogen-free requirement of nuclear grade material is met.

[0014] 4. In the present application, the solid solution state wire can be directly delivered as a finished product, and the performance consistency is good after aging treatment, and the yield strength scattering difference is less than or equal to 30MPa. DETAILED DESCRIPTION

[0015] The application provides a production process of GH4169 alloy spring wire for nuclear power, and those skilled in the art can refer to the content herein and appropriately improve the process parameters to realize. It should be particularly pointed out that all similar replacements and changes are obvious to those skilled in the art and belong to the protection scope of the application. The method and application of the application have been described through the preferred embodiments, and relevant personnel can obviously make changes or appropriate changes and combinations to the method and application herein without departing from the content, spirit and scope of the application, to realize and apply the technical solution of the application.

[0016] In order to make the content of the application more easily and clearly understood, the application is further described in detail below according to specific embodiments. Embodiment

[0017] A production process of GH4169 alloy spring wire for nuclear power, comprising the following steps: S1, raw material preparation: the raw material is prepared according to the following mass percentage: C: 0-0.08%, Cr: 17-21%, Ni: 50-55%, Mo: 2.8-3.2%, Nb: 5.0-5.5%, Al: 0.4-0.7%, Ti: 0.70-1.00%, and the balance is Fe; The above materials are mixed and subjected to vacuum induction melting and electroslag remelting treatment to form an alloy rod with a diameter of 8.0-10.0 mm; S2, skinning treatment: the alloy rod in step S1 is subjected to skinning treatment to remove surface defects; S3, grinding treatment: the alloy rod after the treatment in step S2 is subjected to grinding treatment by a grinding belt, and the surface roughness of the alloy rod after the grinding treatment is Ra≤1.6 μm; S4, drawing treatment: the alloy rod after the treatment in step S3 is subjected to drawing treatment by a drawing die to form an alloy wire; In this embodiment, the reduction rate of the drawing treatment pass is 10-20%, the tolerance of the alloy wire after the drawing treatment is controlled within ±0.02 mm, and the surface roughness of the alloy wire is Ra≤0.4 μm; S5, solid solution treatment: the alloy wire after the treatment in step S4 is placed in a vacuum air quenching furnace, and is kept at 945-965 ℃ for 30 min, and then argon gas is input into the vacuum air quenching furnace for air quenching treatment; In this embodiment, after keeping for 30 min, the air quenching cooling rate is ≥50 ℃ / s, the surface of the wire after cooling is not oxidized, the surface roughness is Ra≤0.8 μm, the surface grain size is ≥8.0 grade, the tensile strength is controlled within 900-1000 MPa, and the batch internal difference is ≤50 MPa; S6, spring making: the alloy wire after the treatment in step S5 is wound and formed into a spring by a spring machine; S7, aging treatment: the shaped spring in step S6 is placed in an aging furnace, and is kept at 710-730℃ for 8h, then is furnace-cooled at a speed of 50-60℃ / h to 610-630℃ and kept at 610-630℃ for 8h again, and finally is air-cooled; In the embodiment, the shaped spring after the aging treatment has a tensile strength of ≥1300MPa, a yield strength of ≥1050MPa, an elongation of ≥12%, and a hardness of ≥42HRC.

[0018] Specifically, the removal depth in step S2 is 0.3-0.5mm.

[0019] Specifically, the granularity of the grinding belt in step S3 is 100-400#, and the grinding speed is 5-20m / min.

[0020] Specifically, the material of the drawing die in step S4 is polycrystalline diamond, and the drawing speed is 10-30m / min.

[0021] Specifically, the water-based drawing oil with a PH value of 8.5-9.0 is added to the drawing die in step S4.

[0022] Specifically, the purity of the argon gas in step S5 is ≥99.999%, and the argon gas pressure is 6.0-7.0bar.

[0023] Specifically, the water-based drawing oil further includes conventional extreme pressure additives, conventional antioxidants, and conventional rust inhibitors.

[0024] In the embodiment, there are inevitable impurities in the raw material, and the impurities need to be controlled and treated according to the mass percentage of Co: 0-0.04%, Mg: 0-0.01%, B: 0-0.006%, Si: 0-0.35%, Mn: 0-0.35%, P: 0-0.015%, S: 0-0.015%, and Cu: 0-0.3%.

[0025] The control treatment mainly relies on the control of the content, and the use of vacuum furnace and protective atmosphere electroslag furnace.

[0026] Comparative Example One The specific production process steps and parameters in the comparative example are the same as those in the embodiment, except that the content of Nb in the prepared raw material in the comparative example is 5.1%, the content of Mo is 2.9%, and the content of Al is 0.6%. The prepared raw material in the comparative example is mixed and subjected to vacuum induction melting and electroslag remelting treatment to form an alloy rod with a diameter of 10.0mm. Peeling treatment: the surface of the alloy rod in the comparative example is removed to a depth of 0.30mm; Grinding treatment: a grinding belt with a specification of 100# is used for grinding, the grinding speed is 12m / min, and Ra=0.65μm. Drawing treatment: the alloy rod is reduced in diameter to 7.0 mm, the pass reduction rate is 12%, the drawing speed is 25 m / min, and Ra=0.26 μm; Solution treatment: in a vacuum air quenching furnace (model VA-01), 955 ℃ for 0.5 hours, argon pressure 6.5 bar, after cooling, the tensile strength is 1050±20 MPa, the grain size is 8.5, and Ra=0.72 μm; Finally, the aging treatment is verified, and the alloy wire of the present comparative example has a tensile strength of 1405 MPa, a yield strength of 1260 MPa, an elongation of 22%, and a hardness of 45.2 HRC.

[0027] Comparative Example Two The present comparative example has the same specific production process steps and parameters as in the examples, except that the Nb content in the preparation raw material is 5.2%, the Mo content is 3.0%, and the Al content is 0.55%. The preparation raw material of the present comparative example is mixed and subjected to vacuum induction melting and electroslag remelting treatment to form an alloy rod with a diameter of 8.0 mm; Skinning treatment: the alloy rod in the present comparative example is removed to a depth of 0.28 mm; Grinding treatment: grinding is performed using a grinding belt with a specification of 400#, the grinding speed is 15 m / min, and Ra=0.75 μm; Drawing treatment: the alloy rod is reduced in diameter to 6.8 mm, the pass reduction rate is 15%, the drawing speed is 20 m / min, and Ra=0.35 μm; Solution treatment: in a vacuum air quenching furnace (model VA-01), 958 ℃ for 0.75 hours, argon pressure 6.2 bar, after cooling, the tensile strength is 980±15 MPa, the grain size is 8.0, and Ra=0.78 μm; Finally, the aging treatment is verified, and the alloy wire of the present comparative example has a tensile strength of 1320 MPa, a yield strength of 1080 MPa, an elongation of 15%, and a hardness of 38.5 HRC.

[0028] Comparative Example Three The present comparative example has the same specific production process steps and parameters as in the examples, except that the Nb content in the preparation raw material is 5.0%, the Mo content is 2.8%, and the Al content is 0.65%. The preparation raw material of the present comparative example is mixed and subjected to vacuum induction melting and electroslag remelting treatment to form an alloy rod with a diameter of 10.2 mm; Skinning treatment: the alloy rod in the present comparative example is removed to a depth of 0.32 mm; Grinding treatment: grinding is performed using a grinding belt with a specification of 100#, the grinding speed is 10 m / min, and Ra=0.68 μm; Drawing process: The alloy wire rod is reduced to a diameter of 7.2 mm, with a reduction rate of 10% per pass, a drawing speed of 30 m / min, and Ra = 0.30 μm; Solution treatment: The sample was held at 952℃ for 1 hour in a vacuum quenching furnace (model VA-01) with an argon pressure of 6.8 bar. After cooling, the tensile strength was measured to be 1020±18MPa, the grain size was grade 8.2, and Ra=0.70μm. Finally, aging treatment was performed to verify that the alloy wire in this comparative example has a tensile strength of 1380 MPa, a yield strength of 1180 MPa, an elongation of 18%, and a hardness of 42.0 HRC.

[0029] The specific embodiments described above further illustrate the technical problems, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A manufacturing process for GH4169 alloy spring wire for nuclear power plants, characterized in that, Includes the following steps: S1. Raw material preparation: The raw materials are prepared by mass percentage as follows: C: 0-0.08%, Cr: 17-21%, Ni: 50-55%, Mo: 2.8-3.2%, Nb: 5.0-5.5%, Al: 0.4-0.7%, Ti: 0.70-1.00%, and the balance is Fe; The raw materials contain unavoidable impurities, which need to be controlled and treated according to the following mass percentages: Co: 0-0.04%, Mg: 0-0.01%, B: 0-0.006%, Si: 0-0.35%, Mn: 0-0.35%, P: 0-0.015%, S: 0-0.015%, and Cu: 0-0.3%. The above materials are mixed and subjected to vacuum induction melting and electroslag remelting to form alloy wire rods with a diameter of 8.0-10.0 mm; S2. Peeling process: Remove the surface defects of the alloy wire rod from step S1 using a peeling machine; S3. Grinding treatment: The alloy wire rods processed in step S2 are ground with a grinding belt. S4. Drawing process: The alloy wire rod processed in step S3 is drawn into alloy wire through a drawing die; S5. Solution treatment: Place the alloy wire treated in step S4 into a vacuum quenching furnace and hold it at 945-965℃ for 30 minutes. Then, argon gas is introduced into the vacuum quenching furnace for gas quenching. S6. Spring making: The alloy wire processed in step S5 is wound into shape by a spring machine; S7. Aging treatment: Place the formed spring from step S6 in an aging furnace and hold it at 710-730℃ for 8 hours. Then, cool it with the furnace at a rate of 50-60℃ / h to 610-630℃ and hold it at that temperature for another 8 hours. Finally, air cool it.

2. The manufacturing process of GH4169 alloy spring wire for nuclear power plants according to claim 1, characterized in that: The removal depth in step S2 is 0.3-0.5mm.

3. The manufacturing process of GH4169 alloy spring wire for nuclear power plants according to claim 1, characterized in that: The abrasive belt used in step S3 has a particle size of 100-400# and a grinding speed of 5-20 m / min.

4. The manufacturing process of GH4169 alloy spring wire for nuclear power plants according to claim 1, characterized in that: The drawing die in step S4 is made of polycrystalline diamond, and the drawing speed is 10-30 m / min.

5. The manufacturing process of GH4169 alloy spring wire for nuclear power plants according to claim 1, characterized in that: In step S4, water-based drawing oil with a pH value of 8.5-9.0 needs to be added to the drawing die.

6. The manufacturing process of GH4169 alloy spring wire for nuclear power plants according to claim 1, characterized in that: In step S5, the argon purity is ≥99.999% and the argon pressure is 6.0-7.0 bar.

7. The manufacturing process of GH4169 alloy spring wire for nuclear power plants according to claim 5, characterized in that: Water-based wire drawing oils also include conventional extreme pressure additives, conventional antioxidants, and conventional rust inhibitors.