Plating layer structure of nickel-plated titanium alloy for high-strength steel
By preparing a nickel-titanium alloy coating on a high-strength steel substrate and coating it with a rare earth electrolytic protective film, the problems of hydrogen embrittlement and pollution in the electroplating process of high-strength steel are solved, achieving a coating structure with low hydrogen embrittlement and low pollution for high-strength steel, and meeting the corrosion resistance and adhesion requirements of relevant standards.
Patent Information
- Application Number
- CN202422868732.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-25
- Publication Date
- 2025-11-11
- Estimated Expiration
- 2034-11-25
AI Technical Summary
High-strength steel is prone to hydrogen embrittlement during electroplating. Existing cadmium-titanium alloy electroplating processes suffer from high pollution and poor plating solution stability, which limits their application in civilian manufacturing.
A nickel-titanium alloy coating is prepared on a high-strength steel substrate using a low-hydrogen-embrittlement nickel-titanium alloy electroplating process, and a rare earth electrolytic protective film is coated on it to prevent hydrogen from diffusing into the substrate and avoid hydrogen embrittlement. At the same time, a low-pollution rare earth electrolytic protection process is adopted.
It effectively prevents hydrogen from diffusing into the substrate, avoids hydrogen embrittlement, reduces pollution, improves coating adhesion and corrosion resistance, and meets relevant standard requirements.
Smart Images
Figure CN223535252U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of metal surface treatment technology, specifically relating to a coating structure of high-strength steel plated with nickel-titanium alloy. Background Technology
[0002] High-strength steel is prone to hydrogen embrittlement during electroplating due to hydrogen permeation, and is susceptible to stress corrosion cracking. Therefore, avoiding hydrogen embrittlement is a crucial issue that must be carefully considered during the processing and use of high-strength steel.
[0003] Studies have shown that when A100 steel parts are electroplated with cadmium-titanium alloy, most of the hydrogen exists in the coating, with only a very small amount penetrating into the substrate. [1] This means that titanium in the cadmium-titanium alloy coating has a barrier effect on the diffusion of hydrogen, which can effectively prevent hydrogen from penetrating into the steel matrix.
[0004] Electroplating cadmium-titanium alloys is highly polluting, limiting its application; currently, this electroplating process is only permitted in the aerospace industry. Furthermore, the poor stability of the plating solution presents challenges to production and application. [2] .
[0005] Therefore, it is necessary to develop new low-hydrogen embrittlement electroplating processes in the civilian product manufacturing industry.
[0006] References: [1]. Yu Bo, Tang Zhihui, Peng Chao, et al. Effect of cyanide-free electroplating of cadmium-titanium alloy on hydrogen embrittlement of steel substrate [J]. Electroplating & Finishing, 2011, 33(11): 1-4. [2]. Lin Qian. Study on cyanide-free electroplating process and electrodeposition behavior of cadmium-titanium alloy [D]. Nanchang, Nanchang Aviation University, 2018. Utility Model Content
[0007] To address the high pollution problem associated with cadmium-titanium alloy plating on high-strength steel substrates, this invention provides a coating structure for high-strength steel plated with nickel-titanium alloy. To achieve the above objective, this invention adopts the following technical solution:
[0008] A high-strength steel nickel-titanium alloy plating structure includes a high-strength steel substrate, a nickel-titanium alloy plating layer sequentially prepared from the inside to the outside on the high-strength steel substrate, and a rare earth electrolytic protective film.
[0009] Preferably, the nickel-titanium alloy coating is prepared using a low-hydrogen embrittlement nickel-titanium alloy electroplating process.
[0010] Preferably, the thickness of the nickel-titanium alloy coating is 8–20 μm.
[0011] Preferably, the rare earth electrolytic protective film is a protective film prepared using the existing rare earth electrolytic protection process.
[0012] Titanium in nickel-titanium alloy coatings has the property of preventing hydrogen from diffusing into the steel substrate. Therefore, during the process of plating nickel-titanium alloys onto high-strength steel surfaces, the nickel-titanium alloy coating itself can effectively prevent hydrogen generated during electroplating from penetrating into the substrate, thus avoiding hydrogen embrittlement of the substrate.
[0013] Compared with the prior art, the present invention has the following beneficial effects:
[0014] 1. The high-strength steel nickel-titanium alloy plating structure disclosed in this utility model is a nickel-titanium alloy plating on a high-strength steel substrate. The nickel-titanium alloy plating can effectively prevent the diffusion of hydrogen elements towards the substrate, thus avoiding hydrogen embrittlement of the steel substrate.
[0015] 2. The high-strength steel nickel-titanium alloy coating structure disclosed in this utility model prepares a rare earth electrolytic protective film on the nickel-titanium alloy coating, overcoming the high pollution problem of preparing a protective film on the coating using the chromate electrolytic protection method. Attached Figure Description
[0016] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, do not constitute an undue limitation of the present invention. In the drawings:
[0017] Figure 1 This is a schematic diagram of the coating structure of Embodiment 1 and Embodiment 2 of this utility model. Detailed Implementation
[0018] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.
[0019] A high-strength steel nickel-titanium alloy plating structure includes a high-strength steel substrate, a nickel-titanium alloy plating layer sequentially prepared from the inside to the outside on the high-strength steel substrate, and a rare earth electrolytic protective film.
[0020] The high-strength steel workpiece substrate is degreased and activated, and then a nickel-titanium alloy coating and a rare earth electrolytic protective film are prepared sequentially.
[0021] Preferably, the thickness of the nickel-titanium alloy coating is 8–20 μm, and it is prepared using the existing nickel-titanium alloy plating process.
[0022] Preferably, the nickel-titanium alloy coating is prepared using the NT-770 nickel-titanium alloy plating process from Chaobang Chemical Co., Ltd.
[0023] Nickel sulfate hexahydrate 50-60 g / L, nickel chloride hexahydrate 5-15 g / L, titanium oxysulfate 5-15 g / L, boric acid 30-40 g / L, trisodium citrate 50-60 g / L, imine succinate 8-12 g / L, NT-770 brightener 2-4 mL / L, NT-770 auxiliary agent 8-12 mL / L, plating bath pH 3.5-5.0, plating bath temperature 50℃-60℃, cathode current density 0.6-1.2 A / dm³ 2 Air agitation.
[0024] High-strength steel workpieces are subjected to hydrogen removal treatment after nickel-titanium alloy plating. Preferably, the workpieces are dehydrogenated at 200℃ for 20-24 hours.
[0025] The rare earth electrolytic protective film is prepared using the current rare earth electrolytic protection process.
[0026] Preferably, the rare earth electrolytic protective film is prepared using a rare earth electrolytic protection process developed by Chaobang Chemical.
[0027] Cerium chloride 1–5 g / L, sodium molybdate 5–15 g / L, HEDP complexing agent 5–30 g / L, anhydrous sodium carbonate 100–150 g / L, electrolyte pH 11.5–12.5 (adjusted with sodium hydroxide solution), cathode current density 0.5–1.5 A / dm³ 2 Operating at room temperature, using the plated part as the cathode and the titanium plate as the anode, electrolysis for 60–120 seconds.
[0028] After electrolytic protection, high-strength steel workpieces are dried at 75℃~85℃ for 15~20 minutes. Example 1
[0029] like Figure 1 As shown, a high-strength steel nickel-titanium alloy plating structure includes a high-strength steel substrate 1, a nickel-titanium alloy plating layer 2 formed sequentially from the inside to the outside on the high-strength steel substrate 1, and a rare earth electrolytic protective film 3.
[0030] 1. Pre-processing:
[0031] The high-strength steel workpiece substrate 1 is subjected to the following process: "alkaline chemical degreasing → water washing → alkaline anodic electrolytic degreasing → water washing → sulfuric acid anodic electrolytic activation → water washing".
[0032] 2. Nickel-plated titanium alloy:
[0033] After pretreatment, the high-strength steel workpiece was coated with a nickel-titanium alloy using Chaobang Chemical's NT-770 nickel-titanium alloy plating process, with a coating thickness of 15μm.
[0034] Nickel sulfate hexahydrate 60 g / L, nickel chloride hexahydrate 15 g / L, titanium oxysulfate 15 g / L, boric acid 40 g / L, trisodium citrate 60 g / L, imine succinate 10 g / L, NT-770 brightener 3 mL / L, NT-770 auxiliary agent 10 mL / L, plating bath pH 4.3, plating tank temperature 52℃, cathode current density 0.8 A / dm³ 2 Air agitation.
[0035] High-strength steel workpieces are plated with nickel-titanium alloy and then subjected to hydrogen removal treatment, with the plated parts being dehydrogenated at 200℃ for 24 hours.
[0036] 3. Rare earth electrolysis protection:
[0037] After high-strength steel workpieces are plated with nickel-titanium alloy, rare earth electrolytic protective films are prepared using the rare earth electrolytic protection process developed by Chaobang Chemical.
[0038] The plated parts were activated for 30 seconds in hydrochloric acid with a volume ratio of acid to water of 1:10, rinsed with water, and then subjected to electrolytic protection.
[0039] Cerium chloride 5 g / L, sodium molybdate 15 g / L, HEDP complexing agent 30 g / L, anhydrous sodium carbonate 130 g / L, electrolyte pH 12 (adjusted with sodium hydroxide solution), cathode current density 1.0 A / dm³ 2 Operating at room temperature, using the plated part as the cathode and the titanium plate as the anode, electrolysis for 80 seconds.
[0040] 4. Drying:
[0041] After electrolytic protection, the high-strength steel workpiece is dried at 80℃ for 15 minutes. Example 2
[0042] like Figure 1 As shown, a high-strength steel nickel-titanium alloy plating structure includes a high-strength steel substrate 1, a nickel-titanium alloy plating layer 2 formed sequentially from the inside to the outside on the high-strength steel substrate 1, and a rare earth electrolytic protective film 3.
[0043] 1. Pre-processing:
[0044] The high-strength steel workpiece substrate 1 is subjected to the following process: "alkaline chemical degreasing → water washing → alkaline anodic electrolytic degreasing → water washing → sulfuric acid anodic electrolytic activation → water washing".
[0045] 2. Nickel-plated titanium alloy:
[0046] After pretreatment, the high-strength steel workpiece was coated with a nickel-titanium alloy using Chaobang Chemical's NT-770 nickel-titanium alloy plating process, with a coating thickness of 15μm.
[0047] Nickel sulfate hexahydrate 55 g / L, nickel chloride hexahydrate 10 g / L, titanium oxysulfate 10 g / L, boric acid 33 g / L, trisodium citrate 55 g / L, imine succinate 10 g / L, NT-770 brightener 3 mL / L, NT-770 auxiliary agent 10 mL / L, plating bath pH 4.2, plating tank temperature 55℃, cathode current density 0.8 A / dm³ 2 Air agitation.
[0048] High-strength steel workpieces are plated with nickel-titanium alloy and then subjected to hydrogen removal treatment, with the plated parts being dehydrogenated at 200℃ for 24 hours.
[0049] 3. Rare earth electrolysis protection:
[0050] After high-strength steel workpieces are plated with nickel-titanium alloy, rare earth electrolytic protective films are prepared using the rare earth electrolytic protection process developed by Chaobang Chemical.
[0051] The plated parts were activated for 30 seconds in hydrochloric acid with a volume ratio of acid to water of 1:10, rinsed with water, and then subjected to electrolytic protection.
[0052] Cerium chloride 3 g / L, sodium molybdate 10 g / L, HEDP complexing agent 18 g / L, anhydrous sodium carbonate 120 g / L, electrolyte pH 12 (adjusted with sodium hydroxide solution), cathode current density 1.0 A / dm³ 2 Operating at room temperature, using the plated part as the cathode and the titanium plate as the anode, electrolyzing for 100 seconds.
[0053] 4. Drying:
[0054] After electrolytic protection, the high-strength steel workpiece is dried at 75℃ for 20 minutes.
[0055] Experimental Example 1:
[0056] 30CrMnSi steel was selected, and hydrogen embrittlement test bars were prepared according to HB 5067.1–2005 "Hydrogen embrittlement test of plating process - Part 1: Mechanical method". A nickel-titanium alloy coating was prepared on the surface of the degreased test bar according to the process requirements of Example 1, and then the plated part was dehydrogenated at 200℃ for 24 hours. The hydrogen embrittlement of the test bar was tested using the constant load endurance tensile test according to HB 5067.1–2005 standard. The test bar did not fracture after 200 hours of tensile testing, and the test results met the standard requirements.
[0057] Experimental Example 2:
[0058] The high-strength steel samples with nickel-titanium alloy plating prepared in Examples 1 and 2 underwent an acetic acid salt spray test for 48 hours according to GB / T 10125–2021 "Artificial Atmosphere Corrosion Test - Salt Spray Test". No rust was found on the surface of the plating, which meets the requirements of GB / T 9797-2005 "Metallic Coatings - Nickel + Chromium and Copper + Nickel + Chromium Electroplating".
[0059] Experimental Example 3:
[0060] The high-strength steel samples with nickel-titanium alloy plating prepared in Examples 1 and 2 were tested for adhesion strength using the thermal shock test method according to GB / T 5270–2005 "Review of Test Methods for Adhesion Strength of Electrodeposited and Chemically Deposited Metallic Coatings on Metal Substrates". The samples were heated to 300°C in a heating furnace and held for 30 minutes. They were then removed and rapidly cooled in water at room temperature. No blistering or peeling of the coating was observed, indicating good adhesion.
[0061] The technical solutions provided by the embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the embodiments of this utility model. The descriptions of the embodiments above are only intended to help understand the principles of the embodiments of this utility model. It should be noted that those skilled in the art may make changes to the specific implementation methods and application scope based on the concept of the embodiments of this utility model, but all such changes should fall within the protection scope of this utility model.
Claims
1. A coating structure for high-strength steel plated with nickel-titanium alloy, characterized in that: It includes a high-strength steel substrate, a nickel-titanium alloy coating formed sequentially from the inside to the outside on the high-strength steel substrate, and a rare earth electrolytic protective film.
2. The coating structure of the high-strength steel nickel-titanium alloy as described in claim 1, characterized in that: The nickel-titanium alloy coating is prepared using a low-hydrogen embrittlement nickel-titanium alloy electroplating process.
3. The coating structure of the high-strength steel nickel-titanium alloy as described in claim 1, characterized in that: The thickness of the nickel-titanium alloy coating is 8–20 μm.
4. The coating structure of the high-strength steel nickel-titanium alloy as described in claim 1, characterized in that: The rare earth electrolytic protective film is a protective film prepared using the current rare earth electrolytic protection process.