A method for surface treatment of a hardenable nickel-based alloy

Abstract

The application provides a hardening type nickel-based alloy surface treatment method, which comprises the following steps: providing a nickel-based alloy workpiece; immersing the workpiece in a first mixed solution, wherein the first mixed solution is prepared by uniformly mixing hydrochloric acid with a volume ratio of 40% to 80%, 5 g / L of ferrous chloride and 2 g / L of nickel chloride; and immersing the workpiece in a second mixed solution, wherein the second mixed solution is prepared by uniformly mixing 20 g / L to 44 g / L of hydrochloric acid and 200 g / L to 440 g / L of ferric chloride. According to the technical scheme of the application, the workpiece is etched by the first mixed solution, the ferrous ions have a complex breaking effect, the activity of the surface material of the workpiece is enhanced, the surface treatment time is shortened, the surface treatment efficiency is improved, the workpiece is etched by the second mixed solution, the trivalent iron ions have a complex shrinking effect, the stubborn pollution elements attached to the surface of the workpiece are removed, the surface quality of the workpiece is improved, and the smoothness of the surface of the workpiece after treatment is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of surface treatment, and particularly relates to a hardening type nickel-based alloy surface treatment method. BACKGROUND

[0002] The nickel-based alloy is an alloy material mainly composed of elements such as nickel, copper, chromium and molybdenum. The nickel-based alloy can be used as a material for electronic tubes, precision alloys, nickel-based high-temperature alloys, nickel-based corrosion-resistant alloys and shape memory alloys. In the fields of energy development, chemical industry, electronics, navigation, aviation and aerospace, the nickel-based alloy has a wide application.

[0003] When the nickel-based alloy material workpiece is cut and formed, the work hardening effect of the nickel-based alloy material surface is particularly significant. In addition, in order to improve the hardness or wear resistance of the nickel-based alloy workpiece, people also often improve the surface hardness of the nickel-based alloy workpiece through surface treatment technology. For example, the patent document with the publication number: CN115044862B discloses a nickel-based alloy surface hardening method for surface treatment of the nickel-based alloy. The first boronizing agent is poured into a container, the nickel-based alloy is buried, and then the container is placed in a heating furnace at 900-950 DEG C for 4-8 h, cooled to 600-620 DEG C for 1-3 h, and then taken out after furnace cooling to room temperature. Under the protection of argon, the second boronizing agent is put into a graphite crucible, the graphite crucible is put into a stainless steel sleeve and heated to, and after 2-4 h of heat preservation, the nickel-based alloy is inserted as a cathode and immersed in the second boronizing agent. The graphite crucible is used as an anode, and the anode and the cathode are respectively connected with a pulse electroplating power supply to perform electrolysis. After electrolysis, the nickel-based alloy is taken out, washed and dried. The patent technology plays a positive role in improving the surface hardness of the nickel-based alloy and improving its wear resistance. However, whether in the cutting process or in the surface treatment process, the surface of the nickel-based alloy workpiece is easy to be subjected to pitting corrosion. Pitting corrosion is a local corrosion form with hidden appearance and great destructive effect, and is one of the important reasons for the damage and failure of easily passivated metals or alloys. Pitting corrosion also affects the overall appearance quality and surface roughness of the formed workpiece, and affects the use performance of the workpiece.

[0004] In the prior art, a patent document with publication number "CN114214631A" discloses an acid pickling process for austenitic iron-nickel-based alloy welded pipes, which comprises the following steps: 1) pre-flushing; 2) acid pickling: placing the pre-flushed iron-nickel-based alloy welded pipe into an acid pickling tank equipped with a 40-50℃ mixed acid solution, acid pickling for 100-120min, and emptying the acid pickling tank to drain the residual acid when the pipe is taken out, wherein the mixed acid solution is an HNO3 and HF mixed solution; 3) immersion type water cleaning + high-pressure water gun flushing; 4) dipping hot water; and 5) air drying. The patent technology uses an acid pickling method to improve the surface finish of nickel-based alloy workpieces. However, this patent technology is generally only applicable to iron-nickel-based alloy welded pipes, and is not suitable for nickel-based alloy workpieces after cutting processing or nickel-based workpieces after surface hardening treatment. The main reason is that the surface hardness of nickel-based workpieces after cutting processing or surface hardening treatment is relatively high, and the corrosion solution used for acid pickling of the workpiece is difficult to react with the workpiece base material, resulting in slow acid pickling speed. In addition, there are many pits on the surface of the nickel-based alloy workpiece after cutting processing or the nickel-based workpiece after surface hardening treatment, which also makes the corrosion solution unable to uniformly react with the workpiece surface base material, causing the workpiece surface to appear uneven, affecting the finish and appearance quality of the workpiece after surface treatment. SUMMARY

[0005] To solve the above technical problems, the present application provides a hardening type nickel-based alloy surface treatment method.

[0006] The present application is realized by the following technical solutions.

[0007] The present application provides a hardening type nickel-based alloy surface treatment method, which comprises the following steps:

[0008] Step one: providing a workpiece, the material of the workpiece is nickel-based alloy;

[0009] Step two: immersing the workpiece in a first mixed solution and taking it out, the first mixed solution is uniformly mixed with the following substance components in accordance with the corresponding proportion:

[0010] Hydrochloric acid: 40% to 80% by volume;

[0011] Ferrous chloride: 5g / L;

[0012] Nickel chloride: 2g / L;

[0013] Step three: immersing the workpiece in a second mixed solution and taking it out, the second mixed solution is uniformly mixed with the following substance components in accordance with the corresponding proportion:

[0014] Hydrochloric acid: 20g / L to 44g / L;

[0015] Ferric chloride: 200 g / L to 440 g / L.

[0016] The hardening type nickel-based alloy surface treatment method further comprises the following steps:

[0017] Step 1: After the workpiece is immersed in BONDERITE C-AK 5948DPM cleaning agent, it is taken out;

[0018] Step 2: After the workpiece is immersed in hot water with a temperature not less than 20℃, it is taken out;

[0019] Step 3: After the workpiece is washed with cold water with a temperature not more than 10℃, step two is performed.

[0020] The workpiece is immersed in BONDERITE C-AK 5948DPM cleaning agent for a duration of not less than 10 min.

[0021] The workpiece is immersed in hot water with a temperature not less than 20℃ for a duration of not less than 2 min.

[0022] The hardening type nickel-based alloy surface treatment method further comprises the following step: after the surface of the workpiece is wiped clean with acetone or anhydrous ethanol, step 1 is performed.

[0023] The workpiece is immersed in the first mixed solution for a duration of 0.5 min to 2 min.

[0024] The workpiece is immersed in the second mixed solution for a duration of 2 min to 5 min.

[0025] The hardening type nickel-based alloy surface treatment method further comprises the following steps:

[0026] After step three is completed, the workpiece is immersed in a third mixed solution and then taken out, wherein the third mixed solution is prepared by uniformly mixing the following components in corresponding proportions: nitric acid: 100 g / L to 180 g / L; hydrofluoric acid: 40 g / L to 80 g / L.

[0027] The hardening type nickel-based alloy surface treatment method further comprises the following step: after step three is completed, the workpiece is dried.

[0028] The material of the workpiece is Inco718 or GH4169.

[0029] The beneficial effects of the present application are that: by adopting the technical scheme of the present application, the first mixed solution made by uniformly mixing hydrochloric acid, ferrous chloride and nickel chloride with high concentration is used for pre-etching the surface of the workpiece, wherein the ferrous ions have a breaking effect, which enhances the activity of the surface material of the workpiece, thereby shortening the surface treatment time of the workpiece and improving the surface treatment efficiency, and the nickel chloride is used for ammonia absorbent to completely remove the ammonia ions in the solution, thereby making the surface of the workpiece uniformly etched, which is conducive to avoiding the phenomenon of local excessive pitting, and then the second mixed solution made by uniformly mixing hydrochloric acid and ferric chloride with low concentration is used for pickling the surface of the workpiece, the trivalent iron ions have a condensation effect, which can quickly combine other metal ions, thereby removing various pollution elements on the surface of the workpiece, thereby improving the surface quality of the workpiece and improving the smoothness of the surface of the workpiece after treatment. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a process flow chart of the present application;

[0031] Figure 2 is an appearance photo of the workpiece A treated by the process method of the present application;

[0032] Figure 3 is an appearance photo of the workpiece B treated by the process method of the present application;

[0033] Figure 4 is an appearance photo of the workpiece C treated by the process method of the present application;

[0034] Figure 5 is an appearance photo of the workpiece D treated by the process method of the present application;

[0035] Figure 6 is an appearance photo of the workpiece E treated by the process method of the present application;

[0036] Figure 7 is an appearance photo of the workpiece F treated by the process method of the present application. DETAILED DESCRIPTION

[0037] The technical scheme of the present application will be further described below, but the scope of protection is not limited to the description.

[0038] As shown in Figure 1 , the present application provides a hardening type nickel-based alloy surface treatment method, comprising the following steps:

[0039] Step one: providing a workpiece, the material of the workpiece is nickel-based alloy;

[0040] Step two: taking out the workpiece after soaking in the first mixed solution, the first mixed solution is made by uniformly mixing the following components according to the corresponding proportion:

[0041] Hydrochloric acid: 40% to 80% by volume;

[0042] Ferrous chloride: 5 g / L;

[0043] Nickel chloride: 2 g / L;

[0044] Step 3: After immersing the workpiece in the second mixed solution, remove it. The second mixed solution is prepared by uniformly mixing the following components in the corresponding proportions:

[0045] Hydrochloric acid: 20 g / L to 44 g / L;

[0046] Ferric chloride: 200 g / L to 440 g / L.

[0047] Specifically, providing the workpiece in step one means first forging the workpiece into shape using a forging method, then aging the workpiece before proceeding to step two.

[0048] The technical solution of this invention first uses a first mixed solution, prepared by uniformly mixing hydrochloric acid, ferrous chloride, and nickel chloride at a relatively high concentration, to pre-impregnate the workpiece surface. Ferrous ions have a complex-breaking effect, enhancing the activity of the workpiece surface material, thereby shortening the surface treatment time and improving surface treatment efficiency. Nickel chloride acts as an ammonia absorbent, completely removing ammonia ions from the solution, thus ensuring uniform etching of the workpiece surface and helping to avoid localized excessive pitting. Then, a second mixed solution, prepared by uniformly mixing hydrochloric acid and ferrous chloride at a lower concentration, is used to pickle the workpiece surface. Ferric ions have a condensation effect, rapidly combining other metal ions to remove various contaminants from the workpiece surface, thereby improving the workpiece surface quality and increasing the smoothness of the treated surface.

[0049] In addition, the surface treatment method for hardened nickel-based alloys also includes the following steps:

[0050] Step 1: Immerse the workpiece in BONDERITE C-AK 5948DPM cleaning solution and then remove it;

[0051] Step 2: Immerse the workpiece in hot water at a temperature of not less than 20°C and then remove it;

[0052] Step 3: After washing the workpiece with cold water at a temperature not exceeding 10℃, proceed to Step 2.

[0053] Specifically, the workpiece is immersed in the BONDERITE C-AK 5948DPM cleaning agent for no less than 10 minutes. The workpiece is immersed in hot water at a temperature of no less than 20℃ for no less than 2 minutes. The hardening type nickel-based alloy surface treatment method further comprises the following step: after the surface of the workpiece is wiped clean with acetone or anhydrous ethanol, the step 1 is performed. Thus, the surface of the workpiece is preliminarily purified, the influence of oil stains and impurities on the surface treatment process of the nickel-based alloy workpiece is avoided, the surface quality of the workpiece after treatment is improved, in addition, the corrosion solution for pickling treatment of the clean surface of the workpiece is more prone to react with the base material, so that the surface treatment time of the workpiece is shortened.

[0054] In addition, the workpiece is immersed in the first mixed solution for 0.5 to 2 minutes. The workpiece is immersed in the second mixed solution for 2 to 5 minutes.

[0055] The hardening type nickel-based alloy surface treatment method further comprises the following steps:

[0056] After step three is completed, the workpiece is taken out after being immersed in a third mixed solution, and the third mixed solution is prepared by uniformly mixing the following components in a corresponding ratio: nitric acid: 100g / L to 180g / L; hydrofluoric acid: 40g / L to 80g / L. The hardening type nickel-based alloy surface treatment method further comprises the following step: after step three is completed, the workpiece is dried. Preferably, the material of the workpiece is Inco718 or GH4169. By immersing the workpiece in the third mixed solution, the residual impurities such as dust on the surface of the workpiece are removed, and a passivation film is formed on the surface of the workpiece, thereby improving the cleanliness and wear resistance of the surface of the workpiece.

[0057] In addition, in order to verify the technical effects of the present application, three groups of workpieces A, B, C, D, E and F with the same shape and size are provided for verification, wherein the workpieces A, C and E are taken out after only step one and step three, and the workpieces B, D and F are taken out after step one to step three, and then the surfaces of the workpieces are photographed, and the obtained photos are as shown in Figures 2 to 7 .

[0058] As can be seen from Figures 2 to 7 , the workpieces A, C and E only immersed in the second mixed solution have many pits on the surface, and the surface finish is poor, while the workpieces B, D and F are sequentially immersed in the first mixed solution and the second mixed solution, and the surface is smooth and has no obvious appearance defects, and the surface finish is high.

Claims

1. A hardenable nickel-base alloy surface treatment method characterized by: It comprises the following steps: Step 1: providing a workpiece, the material of the workpiece being nickel-based alloy; Step 2: taking out the workpiece after soaking in a first mixed solution, the first mixed solution being prepared by uniformly mixing the following components in corresponding proportions: hydrochloric acid: 40% to 80% by volume; ferrous chloride: 5 g / L; nickel chloride: 2 g / L; Step 3: taking out the workpiece after soaking in a second mixed solution, the second mixed solution being prepared by uniformly mixing the following components in corresponding proportions: hydrochloric acid: 20 g / L to 44 g / L; ferric chloride: 200 g / L to 440 g / L.

2. The hardenable nickel-base alloy surface treatment method of claim 1, wherein: The hardening type nickel-based alloy surface treatment method further comprises the following steps: Step 1: taking out the workpiece after soaking in BONDERITE C-AK 5948DPM cleaner; Step 2: taking out the workpiece after soaking in hot water with a temperature not less than 20℃; Step 3: washing the workpiece with cold water with a temperature not more than 10℃, and then performing Step 2.

3. The hardenable nickel-base alloy surface treatment method of claim 2, wherein: The duration of soaking the workpiece in BONDERITE C-AK 5948DPM cleaner is not less than 10 min.

4. The hardenable nickel-base alloy surface treatment method of claim 2, wherein: The duration of soaking the workpiece in hot water with a temperature not less than 20℃ is not less than 2 min.

5. The hardenable nickel-base alloy surface treatment method of claim 2, wherein: The hardening type nickel-based alloy surface treatment method further comprises the following step: wiping the surface of the workpiece clean with acetone or anhydrous ethanol, and then performing Step 1.

6. The hardenable nickel-base alloy surface treatment method of claim 1, wherein: The duration of soaking the workpiece in the first mixed solution is 0.5 min to 2 min.

7. The hardenable nickel-base alloy surface treatment method of claim 1, wherein: The duration of soaking the workpiece in the second mixed solution is 2 min to 5 min.

8. The hardenable nickel-base alloy surface treatment method of claim 1, wherein: The hardening type nickel-based alloy surface treatment method further comprises the following steps: After completing Step 3, taking out the workpiece after soaking in a third mixed solution, the third mixed solution being prepared by uniformly mixing the following components in corresponding proportions: nitric acid: 100 g / L to 180 g / L; hydrofluoric acid: 40 g / L to 80 g / L.

9. The hardenable nickel-base alloy surface treatment method of claim 1, wherein: The hardening type nickel-based alloy surface treatment method further comprises the following step: after completing Step 3, drying the workpiece.

10. The hardenable nickel-base alloy surface treatment method of any one of claims 1 to 9, wherein: The material of the workpiece is Inco718 or GH4169.

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