Stainless steel and chemical nickel plating method thereof

Abstract

The invention discloses stainless steel and a chemical nickel plating method thereof. The chemical nickel plating method sequentially comprises the steps of oil removal, first-time cleaning, first-time drying, sand blasting, etching, impact nickel plating, second-time cleaning, activation, third-time cleaning, chemical nickel plating, cleaning and second-time drying. According to the method, the etched stainless steel part is not cleaned and is directly subjected to impact nickel plating, and activation of the surface of the stainless steel part is guaranteed as much as possible. In order to guarantee the uniformity of a plating layer in the chemical nickel plating process, the part is turned over regularly, bubbles generated in the chemical nickel plating process are eliminated, and the nickel plating quality is improved. The surface roughness of the stainless steel substrate is improved by adding sand blasting before plating, the probability of mechanical inlaying of the chemical nickel plating layer and the stainless steel substrate is increased, and then the binding force of the plating layer is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of stainless steel preparation, and in particular relates to stainless steel and a chemical nickel plating method thereof. Background Art

[0002] Stainless steel materials are widely used in industrial production because of their good corrosion resistance and ductility. 0Cr17Ni4Cu4Nb is a precipitation hardening martensitic stainless steel with high strength, good corrosion resistance and excellent processing performance. In order to improve its wear resistance, the parts need to be surface treated. Chemical nickel plating has the characteristics of high hardness, excellent wear resistance and low porosity, and is often used to replace chrome plating to improve the wear resistance of parts. However, the passivation coefficient of martensitic stainless steel is relatively large, and the commonly used acid and electrolytic activation cannot guarantee the bonding strength of the coating, and problems such as coating shedding often occur.

[0003] The patent document with the announcement number CN102719868A discloses a nickel plating process for stainless steel fasteners, and the steps are as follows: Step 1: Roll nickel plating: Place the stainless steel fastener in the electroplating drum, and place the electroplating drum in the nickel priming solution tank, in which a nickel priming solution composed of nickel chloride, hydrochloric acid and water is placed, wherein: the concentration of nickel chloride is 150-200g / L, the concentration of hydrochloric acid is 100-120g / L, and the electroplating is 10min-20min; Step 2: Secondary nickel plating: Place the electroplating drum that ends step 1 in the secondary nickel plating solution tank, and the secondary nickel plating solution tank contains a secondary nickel plating solution composed of nickel chloride, nickel sulfate, boric acid and water, wherein: the concentration of nickel chloride is 60-75g / L, the concentration of nickel sulfate is 180-220g / L, the concentration of boric acid is 40-55g / L, and the electroplating is 50min-60min. This process requires three nickel platings, which has higher requirements for equipment and process control.

[0004] The patent document with the announcement number CN1526856A discloses a method for nickel plating stainless steel wire, which comprises a stainless steel wire, a DC power supply, a plating solution and a metal nickel plate to form an electroplating circuit, and the main process steps include: cleaning to remove dirt on the surface of the stainless steel wire, using a current of 0.020-0.030A / stainless steel wire, at 15-35°C, pre-nickel plating with a mixed aqueous solution of 5-15% hydrochloric acid and 15-30% nickel chloride, using a current of 0.010-0.035A / stainless steel wire at 15-35°C, using a mixed aqueous solution of 20-40% nickel sulfate and 2-6% boric acid, and during the pre-nickel plating and nickel plating process, the stainless steel wire continuously enters and exits the plating solution. This method is used for nickel plating of stainless steel wire, and it is difficult to change the surface roughness of plate-shaped stainless steel by chemical surface treatment, which has certain limitations for plate-shaped stainless steel. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a stainless steel and a chemical nickel plating method thereof.

[0006] The present invention is achieved through the following technical solutions.

[0007] The invention provides stainless steel and a chemical nickel plating method thereof, comprising a process of sequentially nickel plating the stainless steel with impact nickel plating and chemical nickel plating.

[0008] Preferably, the chemical nickel plating process includes degreasing, first cleaning, first drying, sandblasting, etching, impact nickel plating, second cleaning, activation, third cleaning, chemical nickel plating, cleaning and second drying steps in sequence, and the deposition rate of the nickel plating layer is 10 μm / h.

[0009] Preferably, the nickel impact plating step comprises using solution A at room temperature with a current density of 2-10 A / dm 2 , the electroplating time is 1-15 minutes, and the sandblasting step includes sandblasting the stainless steel surface with 50-100 mesh zirconium beads.

[0010] Preferably, the solution A comprises 150-250 g / L of nickel chloride and 150-200 mL / L of hydrochloric acid.

[0011] Preferably, the chemical nickel plating step includes performing the step at a nickel plating solution temperature of 60-100° C. and a pH value of 5.5-6.5, the chemical nickel plating time is determined according to the thickness of the nickel plating layer, and the stainless steel part is turned over once every 1-8 minutes during the chemical nickel plating process.

[0012] Preferably, the materials used in the chemical nickel plating step include 20-25 g / L nickel sulfate, 20-25 g / L reducing agent sodium hypophosphite, 20-25 g / L complexing agent lactic acid, and 5-8 g / L auxiliary complexing agent malic acid.

[0013] Preferably, the degreasing step includes using an ultrasonic alkaline degreasing method, the degreasing time is 10-15 minutes, the first cleaning, the second cleaning and the third cleaning all use pure water, and the first drying and the second drying include air cooling and static drying.

[0014] Preferably, the ultrasonic alkaline degreasing step includes using 8-10% of a degreasing agent for degreasing, and the ultrasonic frequency is 30-60 kHz.

[0015] Preferably, the etching step includes using 30-50% analytically pure hydrochloric acid as an etching solution for 1-10 minutes, and the activation step includes using 10-30% analytically pure hydrochloric acid as an etching solution for 1-10 minutes.

[0016] A 0Cr17Ni9Cu4Nb stainless steel prepared by the chemical nickel plating method.

[0017] The beneficial effects of the present invention are:

[0018] In the method of the present invention, the stainless steel parts are directly subjected to impact nickel plating without being cleaned after being etched, so as to ensure the activation of the surface of the stainless steel parts as much as possible. In the chemical nickel plating process, in order to ensure the uniformity of the coating, the parts are turned over regularly to remove the bubbles generated in the chemical nickel plating process and improve the quality of nickel plating. By adding sandblasting before plating to improve the surface roughness of the stainless steel substrate, the probability of mechanical inlay between the chemical nickel plating layer and the stainless steel substrate is increased, thereby ensuring the bonding strength of the coating. The process of the present invention is simple, and the bonding strength between the stainless steel parts and the coating can be effectively improved by selecting the process parameters. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0020] Embodiment 1:

[0021] A stainless steel and a chemical nickel plating method thereof, comprising the steps of degreasing, first cleaning, first drying, sandblasting, etching, impact nickel plating, second cleaning, activation, third cleaning, chemical nickel plating, cleaning and second drying in sequence, wherein the deposition rate of the nickel plating layer is 10 μm / h.

[0022] The nickel strike plating step includes using solution A at room temperature with a current density of 2A / dm 2 The specific current can be calculated according to the surface area of ​​the stainless steel parts, and the electroplating time is 1 minute. The sandblasting step includes using 50-mesh zirconium beads to sandblast the stainless steel surface to improve the surface roughness of the substrate, increase the probability of mechanical inlay between the chemical nickel plating layer and the substrate, and thus ensure the bonding strength of the coating. After sandblasting, the parts are connected in series with stainless steel parts using copper wire.

[0023] The solution A includes 150 g / L of nickel chloride and 150 mL / L of hydrochloric acid.

[0024] The chemical nickel plating step includes performing the process at a nickel plating solution temperature of 60° C. and a pH value of 5.5 for 5 minutes, and turning the stainless steel piece once every 1 minute during the chemical nickel plating process.

[0025] The materials used in the chemical nickel plating step include 20 g / L nickel sulfate, 20 g / L reducing agent sodium hypophosphite, 20 g / L complexing agent lactic acid, and 5 g / L auxiliary complexing agent malic acid.

[0026] The degreasing step includes using an ultrasonic alkaline degreasing method, the degreasing time is 10 minutes, the first cleaning, the second cleaning and the third cleaning all use pure water, the cleaning is to use pure water to rinse for 5 minutes, and the first drying and the second drying include air cooling and static drying.

[0027] The ultrasonic alkaline degreasing step includes using 8% of degreasing agent WY_826 for degreasing, and the ultrasonic frequency is 30 kHz.

[0028] The etching step includes using 30% analytical pure hydrochloric acid as an etching solution, etching for 1 minute, to remove the oxide layer on the surface of the stainless steel part.

[0029] The activation step includes using 10% analytical pure hydrochloric acid to activate for 1 minute, and the activation process needs to swing up and down and left and right.

[0030] Embodiment 2:

[0031] A stainless steel and a chemical nickel plating method thereof, comprising the steps of degreasing, first cleaning, first drying, sandblasting, etching, impact nickel plating, second cleaning, activation, third cleaning, chemical nickel plating, cleaning and second drying in sequence, wherein the deposition rate of the nickel plating layer is 10 μm / h.

[0032] The nickel strike plating step includes using solution A at room temperature with a current density of 10 A / dm 2 The specific current can be calculated according to the surface area of ​​the stainless steel parts, and the electroplating time is 15 minutes. The sandblasting step includes using 100-mesh zirconium beads to sandblast the stainless steel surface to improve the surface roughness of the substrate, increase the probability of mechanical inlay between the chemical nickel plating layer and the substrate, and thus ensure the bonding strength of the coating. After sandblasting, the parts are connected in series with stainless steel parts using copper wire.

[0033] The solution A includes 250 g / L of nickel chloride and 200 mL / L of hydrochloric acid.

[0034] The chemical nickel plating step includes performing the process at a nickel plating solution temperature of 100° C. and a pH value of 6.5 for 5 minutes, and turning the stainless steel piece once every 8 minutes during the chemical nickel plating process.

[0035] The materials used in the chemical nickel plating step include 25 g / L nickel sulfate, 25 g / L reducing agent sodium hypophosphite, 25 g / L complexing agent lactic acid, and 8 g / L auxiliary complexing agent malic acid.

[0036] The degreasing step includes using an ultrasonic alkaline degreasing method, the degreasing time is 15 minutes, the first cleaning, the second cleaning and the third cleaning all use pure water, the cleaning is to use pure water to rinse for 5 minutes, and the first drying and the second drying include air cooling and static drying.

[0037] The ultrasonic alkaline degreasing step includes using 10% of degreasing agent WY_826 for degreasing, and the ultrasonic frequency is 60 kHz.

[0038] The etching step includes using 50% analytical pure hydrochloric acid as an etching solution, etching for 10 minutes, and removing the oxide layer on the surface of the stainless steel part.

[0039] The activation step includes using 30% analytical pure hydrochloric acid to activate for 10 minutes, and the activation process needs to swing up and down and left and right.

[0040] Embodiment 3:

[0041] A stainless steel and a chemical nickel plating method thereof, comprising the steps of degreasing, first cleaning, first drying, sandblasting, etching, impact nickel plating, second cleaning, activation, third cleaning, chemical nickel plating, cleaning and second drying in sequence, wherein the deposition rate of the nickel plating layer is 10 μm / h.

[0042] The nickel strike plating step includes using solution A at room temperature with a current density of 7A / dm 2 The specific current can be calculated according to the surface area of ​​the stainless steel parts, and the electroplating time is 5 minutes. The sandblasting step includes using 80-mesh zirconium beads to sandblast the stainless steel surface to improve the surface roughness of the substrate, increase the probability of mechanical inlay between the chemical nickel plating layer and the substrate, and thus ensure the bonding strength of the coating. After sandblasting, the parts are connected in series with stainless steel parts using copper wire.

[0043] The solution A includes 210 g / L of nickel chloride and 180 mL / L of hydrochloric acid.

[0044] The chemical nickel plating step includes performing the process at a nickel plating solution temperature of 60-100° C. and a pH value of 6.0 for 5 minutes, and turning the stainless steel piece once every 5 minutes during the chemical nickel plating process.

[0045] The materials used in the chemical nickel plating step include 23 g / L nickel sulfate, 22 g / L reducing agent sodium hypophosphite, 22 g / L complexing agent lactic acid, and 7 g / L auxiliary complexing agent malic acid.

[0046] The degreasing step includes using an ultrasonic alkaline degreasing method, the degreasing time is 12 minutes, the first cleaning, the second cleaning and the third cleaning all use pure water, the cleaning is to use pure water to rinse for 5 minutes, and the first drying and the second drying include air cooling and static drying.

[0047] The ultrasonic alkaline degreasing step includes using 9% of degreasing agent WY_826 for degreasing, and the ultrasonic frequency is 40 kHz.

[0048] The etching step includes using 40% analytical pure hydrochloric acid as an etching solution, etching for 3 minutes, to remove the oxide layer on the surface of the stainless steel part.

[0049] The activation step includes using 25% analytical pure hydrochloric acid to activate for 3 minutes, and the activation process needs to swing up and down and left and right.

[0050] Comparative Example 1:

[0051] A stainless steel and a method for chemical nickel plating thereof are substantially the same as those in Example 3, except that the sandblasting step is not performed.

[0052] Comparative Example 2:

[0053] A stainless steel and a method for chemical nickel plating thereof are substantially the same as those in Example 3, except that the current density used in the impact nickel plating step is 0.5 A / dm 2 .

[0054] Comparative Example 3:

[0055] A stainless steel and a method for chemical nickel plating thereof are substantially the same as those in Example 3, except that the current density used in the impact nickel plating step is 15 A / dm 2 .

[0056] The 0Cr17Ni9Cu4Nb stainless steel parts with a size of 10cm*10cm*3cm that were nickel-plated by the methods of Examples 1-3 and Comparative Examples 1-7 were tested for the bonding strength of the coating by a thermal shock method, wherein the nickel-plated stainless steel parts were heated to 300°C, kept warm for 1 hour, then taken out and placed in cold water to cool to room temperature, and then the parts were dried. The coating was observed under a 20x microscope. The stainless steel coatings prepared in Examples 1-3 did not fall off, and the stainless steel coatings prepared in Comparative Examples 1-3 had a shedding area greater than 20%.

Claims

1. A method for chemical nickel plating of stainless steel, characterized in that: It includes the process of nickel plating stainless steel by impact nickel plating and chemical nickel plating in sequence.

2. A method for chemical nickel plating of stainless steel as claimed in claim 1, characterized in that: The chemical nickel plating process sequentially comprises the steps of degreasing, first cleaning, first drying, sandblasting, etching, impact nickel plating, second cleaning, activation, third cleaning, chemical nickel plating, cleaning and second drying, and the deposition rate of the nickel plating layer is 10 μm / h.

3. A method for chemical nickel plating of stainless steel as claimed in claim 2, characterized in that: The nickel impact plating step comprises using solution A at room temperature with a current density of 2-10A / dm 2 , the electroplating time is 1-15 minutes, and the sandblasting step includes sandblasting the stainless steel surface with 50-100 mesh zirconium beads.

4. A method for chemical nickel plating of stainless steel as claimed in claim 3, characterized in that: The solution A comprises 150-250 g / L of nickel chloride and 150-200 mL / L of hydrochloric acid.

5. A stainless steel and a chemical nickel plating method thereof as claimed in claim 2, characterized in that: The chemical nickel plating step includes: performing the chemical nickel plating at a nickel plating solution temperature of 60-100° C. and a pH value of 5.5-6.5; the chemical nickel plating time is determined according to the thickness of the nickel plating layer; and turning the stainless steel piece once every 1-8 minutes during the chemical nickel plating process.

6. A method for chemical nickel plating of stainless steel as claimed in claim 5, characterized in that: The materials used in the chemical nickel plating step include 20-25 g / L nickel sulfate, 20-25 g / L reducing agent sodium hypophosphite, 20-25 g / L complexing agent lactic acid, and 5-8 g / L auxiliary complexing agent malic acid.

7. A method for chemical nickel plating of stainless steel as claimed in claim 2, characterized in that: The degreasing step includes using an ultrasonic alkaline degreasing method, the degreasing time is 10-15 minutes, the first cleaning, the second cleaning and the third cleaning all use pure water, and the first drying and the second drying include air cooling and static drying.

8. A method for chemical nickel plating of stainless steel as claimed in claim 7, characterized in that: The ultrasonic alkaline degreasing step includes using 8-10% of a degreasing agent to remove oil, and the ultrasonic frequency is 30-60 kHz.

9. A method for chemical nickel plating of stainless steel as claimed in claim 2, characterized in that: The etching step includes using 30-50% analytical pure hydrochloric acid as an etching solution for 1-10 minutes, and the activation step includes using 10-30% analytical pure hydrochloric acid as an etching solution for 1-10 minutes.

10. A 0Cr17Ni9Cu4Nb stainless steel prepared by the chemical nickel plating method according to any one of claims 1 to 9.