阅读说明：本技术 一种特种钢表面处理方法 (Special steel surface treatment method ) 是由 刘洋 于 2020-07-30 设计创作，主要内容包括：本发明公开了一种特种钢表面处理方法,包括以下步骤：步骤a：用Cr离子束对特种钢基体进行表面清洗后注入Cr离子,在特种钢基体上沉积铬膜；步骤b：超声清洗：步骤c：真空处理：步骤d：注入氮离子：步骤e：注入钛离子：步骤f：依次循环步骤d、步骤e至少2次,使氮离子与钛离子都进行至少2次注入；步骤g：将真空室内气压恢复常压,并冷却至室温。本发明结合沉积铬膜和离子注入,铬膜使得轴承钢基体表面具有良好的硬度、韧性、耐磨性和耐腐蚀性,在此基础上进行离子注入,在铬膜表面发生反应形成非晶层以及陶瓷相,造成许多位错缺陷,可促进致钝元素铬在表面富集,使得钝化膜稳定性提高,薄膜的耐腐蚀性提高。(The invention discloses a special steel surface treatment method, which comprises the following steps: step a: cleaning the surface of the special steel substrate by using a Cr ion beam, injecting Cr ions, and depositing a chromium film on the special steel substrate; step b: ultrasonic cleaning: step c: and (3) vacuum treatment: step d: and (3) nitrogen ion implantation: step e: and (3) titanium ion implantation: step f: d, e, circulating the step d and the step e for at least 2 times in sequence, so that nitrogen ions and titanium ions are implanted for at least 2 times; step g: and (5) recovering the air pressure in the vacuum chamber to normal pressure, and cooling to room temperature. The method combines the deposition of the chromium film and the ion implantation, the chromium film ensures that the surface of the bearing steel matrix has good hardness, toughness, wear resistance and corrosion resistance, the ion implantation is carried out on the basis, the reaction is carried out on the surface of the chromium film to form an amorphous layer and a ceramic phase, so that a plurality of dislocation defects are caused, the enrichment of the passivation element chromium on the surface can be promoted, the stability of the passivation film is improved, and the corrosion resistance of the film is improved.)

1. A special steel surface treatment method is characterized by comprising the following steps: the method comprises the following steps:

step a: cleaning the surface of the special steel substrate by using a Cr ion beam, injecting Cr ions, and depositing a chromium film on the special steel substrate;

step b: ultrasonic cleaning: b, placing the special steel obtained in the step a into an acetone solution with the purity of more than 99.9 percent for ultrasonic cleaning twice, wherein each ultrasonic cleaning lasts for 9-14 min;

step c: and (3) vacuum treatment: placing the special steel cleaned in the step b on a sample table of a vacuum chamber,the vacuum chamber is vacuumized to the vacuum degree of 2.2 × 10^-5Pa～3.2×10^-5After Pa, slowly rotating the sample platform of the vacuum chamber along the axis of the sample platform at a constant speed, and simultaneously modifying the surface of the special steel by using an ion implanter;

step d: and (3) nitrogen ion implantation: c, performing nitrogen ion implantation treatment on the special steel by using an ion implanter while the special steel slowly rotates around the axis of the special steel at a constant speed in the step c;

step e, titanium ion implantation, wherein a metal target with the purity of 99.8 percent is adopted as a metal source of the metal ions, the implantation energy of the metal ions implanted for the first time is 25 keV-90 keV, the implantation energy is sequentially reduced to the lowest 20keV, and the total ion implantation dose is 2.5 × 10¹⁷ions/cm²～3.5×10¹⁷ions/cm²；

Step f: d, e, circulating the step d and the step e for at least 2 times in sequence, so that nitrogen ions and titanium ions are implanted for at least 2 times;

step g: and (5) recovering the air pressure in the vacuum chamber to normal pressure, and cooling to room temperature.

2. A special steel surface treatment method according to claim 1, characterized in that: the surface modification adopts continuous overlapping injection of nitrogen ions and titanium ions.

3. A special steel surface treatment method according to claim 2, characterized in that: the conditions of the Cr ion implantation in the step a are as follows: 6-8kV, 3-5mA beam current, and 5500-6500mC of injected charge quantity.

4. A special steel surface treatment method according to claim 3, characterized in that: in the step a, a magnetic filtration cathode vacuum arc plasma deposition coating technology is adopted to deposit a chromium film; the deposition conditions for the chromium film deposition were: the arc flow 100-.

5. A special steel surface treatment method according to claim 4, characterized in thatCharacterized in that the nitrogen ion gas source in the step d adopts nitrogen with the purity of 99.99 percent, the energy of each injection is 80keV to 95keV, and the total injection dose is 2.0 × 10¹⁷ions/cm²～3.5×10¹⁷ions/cm²。

Technical Field

The invention relates to a treatment method, in particular to a special steel surface treatment method.

Background

With the continuous development of the technology, the bearing bears larger and larger load, the service life of the special steel precision bearing which is not subjected to any surface strengthening treatment cannot meet the use requirements of some working parts under the heavy-load high-speed condition, and the bearing which is not subjected to the surface strengthening treatment has low bearing capacity and strength, namely the service life of the bearing is short.

The surface corrosion resistance of bearing steel is still a certain difference from the future ideal bearing steel, and further improvement of the surface corrosion resistance of bearing steel is required. In the surface treatment technology for improving the corrosion resistance of bearing steel, the composite strengthening heat treatment and coating technology still have the problems of difficult process control, large internal stress and the like, so that the popularization and the application of the technology are limited. The ion implantation technology is widely used for surface strengthening of steel at present, but the method for improving the surface corrosion resistance still cannot meet the harsh requirement of the working condition of the bearing steel, and the surface corrosion resistance of the bearing steel needs to be further improved.

Disclosure of Invention

In order to solve the defects of the technology, the invention provides a special steel surface treatment method.

In order to solve the technical problems, the invention adopts the technical scheme that: a special steel surface treatment method comprises the following steps:

step a: cleaning the surface of the special steel substrate by using a Cr ion beam, injecting Cr ions, and depositing a chromium film on the special steel substrate; in order to remove the surface oxidation layer and make the chromium film have better bonding force, Cr ion beams are used for carrying out surface cleaning and Cr ion implantation on the special steel substrate before the chromium film is deposited.

Step b: ultrasonic cleaning: b, placing the special steel obtained in the step a into an acetone solution with the purity of more than 99.9 percent for ultrasonic cleaning twice, wherein each ultrasonic cleaning lasts for 9-14 min;

c, vacuum treatment, namely putting the special steel cleaned in the step b on a sample table of a vacuum chamber, and vacuumizing the vacuum chamber until the vacuum degree is 2.2 × 10^-5Pa～3.2×10^-5After Pa, slowly rotating the sample platform of the vacuum chamber along the axis of the sample platform at a constant speed, and simultaneously modifying the surface of the special steel by using an ion implanter;

step d: and (3) nitrogen ion implantation: c, performing nitrogen ion implantation treatment on the special steel by using an ion implanter while the special steel slowly rotates around the axis of the special steel at a constant speed in the step c;

step e: and (3) titanium ion implantation: the metal source of the metal ions adopts a metal target with the purity of 99.8 percent, and the implantation energy of the first implantation of the metal ions is25keV to 90keV, and the implantation energy is decreased to the lowest 20keV, and the total ion implantation dose is 2.5 × 10¹⁷ions/cm²～3.5×10¹⁷ions/cm²；

Step f: d, e, circulating the step d and the step e for at least 2 times in sequence, so that nitrogen ions and titanium ions are implanted for at least 2 times;

step g: and (5) recovering the air pressure in the vacuum chamber to normal pressure, and cooling to room temperature.

Further, the surface modification adopts continuous overlapping implantation of nitrogen ions and titanium ions.

Further, the conditions of the Cr ion implantation in step a are: 6-8kV, 3-5mA beam current, and 5500-6500mC of injected charge quantity. The average charge amount Qr of the chromium ions was 2.1. Preferably, a voltage of 7.5kV and a beam current of 4mA are adopted, and the injected charge quantity is 6000 mC.

Further, in the step a, a magnetic filtration cathode vacuum arc plasma deposition coating technology is adopted to deposit a chromium film; the Cr film is formed by a magnetic filtration cathode vacuum arc plasma deposition coating (FCVA) technology, the film forming density is high, no air hole exists, the bonding force between the Cr film and a substrate is better, and the defect density is lower, so that the Cr film has good hardness, toughness, wear resistance and corrosion resistance.

The deposition conditions for the chromium film deposition were: the arc flow 100-. Preferably, the arc current 110A is biased at-80V, the beam current is 480mA, the duty ratio is 90%, the total charge amount is 6100 × 100mC, and the deposition time is 50 min.

Furthermore, the nitrogen ion gas source in the step d adopts nitrogen with the purity of 99.99 percent, the energy of each injection is 80 keV-95 keV, and the total injection dose is 2.0 × 10¹⁷ions/cm²～3.5×10¹⁷ions/cm²。

The method combines the deposition of the chromium film and the ion implantation, the chromium film ensures that the surface of the bearing steel substrate has good hardness, toughness, wear resistance and corrosion resistance, the ion implantation is carried out on the basis, the reaction is carried out on the surface of the chromium film to form an amorphous layer and a ceramic phase, so that a plurality of dislocation defects are caused, the enrichment of chromium which is a passivation element on the surface can be promoted, the stability of a passivation film is improved, and the corrosion resistance of the film is improved.

Detailed Description

The present invention will be described in further detail with reference to specific embodiments.

A special steel surface treatment method comprises the following steps:

wherein, before surface modification, the step of removing grease is carried out: firstly, removing grease on the surface of the special steel substrate to be treated by using a metal degreasing solvent, then putting the special steel substrate into pollution-free tetrachloroethylene to soak for 25 minutes, taking out the special steel substrate, completely absorbing residual solvent by using rice paper, wiping the surface of the special steel substrate by using absorbent cotton, and finally wiping the special steel substrate by using clean silk; the metal degreasing solvent is a common metal degreasing solvent sold in the market, and comprises the components of sodium hydroxide, sodium carbonate, sodium phosphate decahydrate, sodium silicate, a detergent, a corrosion inhibitor, solvent water and the like; the tetrachloroethylene used for cleaning can also be replaced by other organic solvents.

Wherein, before surface modification, the step of removing rust spots is carried out: soaking and cleaning the special steel substrate for 15 minutes by using a metal cleaning agent with a rust removing function to ensure that the surface of the special steel substrate does not have micro rust spots; the metal rust remover is a commercially available common metal rust remover and comprises the following components: surfactant, organic acid, promoter, corrosion inhibitor, deionized water and the like.

Wherein, before the surface modification, the method also comprises the following steps of: and (3) putting the special steel substrate into acetone, carrying out ultrasonic cleaning for 30 minutes, taking out, and wiping with clean silk cloth. When the special steel matrix is wiped dry, the smooth surface of the special steel matrix is wiped along the same direction, so that no water stain or impurity residue is left on the surface of the special steel matrix; the special part (working surface) of the special steel substrate is mainly wiped, and the other parts (non-working surfaces) of the special steel substrate ensure that the surface of the special steel substrate does not have water stains and impurity residues. Meanwhile, the material is not wiped by the polluted and wetted silk.

Before surface modification, the pretreated special steel substrate is put into deionized water, is ultrasonically cleaned for 30 minutes and then is taken out, and is scrubbed, wiped and dried by using clean silk cloth (the scrubbing liquid is placed in a vacuum oven to be dried for 3 hours).

Step a: cleaning the surface of the special steel substrate by using a Cr ion beam, injecting Cr ions, and depositing a chromium film on the special steel substrate;

the method comprises the steps of ultrasonically cleaning a sample by acetone before preparing a chromium film, adopting a high-purity chromium target as a cathode, before deposition, firstly cleaning the surface of the sample by using a Cr ion beam led out from a magnetic filtration cathode arc vacuum system, and injecting Cr ions, wherein the injection conditions comprise 7.5kV of voltage, 4mA beam current, 6000mC of injection charge amount and 2.1 of average charge amount Qr of the Cr ions, then depositing the chromium film on a substrate, the deposition conditions comprise arc current 110A, 80V of bias voltage, 480mA of beam current, 90% of duty ratio, 6100 × 100 total charge amount, 50min of deposition time, injecting nitrogen ions and then titanium ions in an MEVVA ion injector, and the numerical parameters comprise 30keV of injection energy and 3 × 10 of injection dose of 3 3510 mC¹⁷ions/cm²。

Step b: ultrasonic cleaning: b, placing the special steel obtained in the step a into an acetone solution with the purity of more than 99.9 percent for ultrasonic cleaning twice, wherein each ultrasonic cleaning lasts for 9-14 min;

c, vacuum treatment, namely putting the special steel cleaned in the step b on a sample table of a vacuum chamber, and vacuumizing the vacuum chamber until the vacuum degree is 2.2 × 10^-5Pa～3.2×10^-5After Pa, slowly rotating the sample platform of the vacuum chamber along the axis of the sample platform at a constant speed, and simultaneously modifying the surface of the special steel by using an ion implanter; the surface modification adopts continuous overlapping implantation of nitrogen ions and titanium ions.

D, injecting nitrogen ions, namely performing nitrogen ion injection treatment on the special steel by using an ion injector while the special steel slowly rotates around the axis of the special steel at a constant speed in the step c, wherein a nitrogen ion gas source adopts nitrogen with the purity of 99.99 percent, the injection energy is 80 keV-95 keV each time, and the total injection dose is 2.0 × 10¹⁷ions/cm²～3.5 ×10¹⁷ions/cm²。

Step e, titanium ion implantation, wherein a metal target with the purity of 99.8 percent is adopted as a metal source of the metal ions, the implantation energy of the metal ions implanted for the first time is 25 keV-90 keV, the implantation energy is sequentially reduced to the lowest 20keV, and the total ion implantation dose is 2.5 × 10¹⁷ions/cm²～3.5×10¹⁷ions/cm²；

Step f: d, e, circulating the step d and the step e for at least 2 times in sequence, so that nitrogen ions and titanium ions are implanted for at least 2 times;

step g: and (5) recovering the air pressure in the vacuum chamber to normal pressure, and cooling to room temperature.

In order to improve the bearing capacity and the service life of the special steel, the special steel needs to be subjected to surface strengthening treatment. The surface of the material is strengthened by a plurality of methods, including spraying, laser surface strengthening, ion plating, plasma-based ion implantation and the like. The special steel is bearing steel, and only the plasma-based ion implantation technology can be used for surface strengthening treatment of the precision bearing in a plurality of surface strengthening technologies due to the strict requirement of the precision bearing on the dimensional precision. The plasma-based ion implantation technique has the following advantages:

1) the limitation of sight processing is overcome, and all-round injection is realized: in the plasma-based ion implantation process, a workpiece (a precision bearing in the embodiment) is buried in plasma, almost every exposed metal surface can attract ions by virtue of a strong electric field generated by pulse negative bias applied to the workpiece, so that the workpiece can be subjected to all-around ion implantation from all directions, and the application problem of the ion implantation on the workpiece with a complicated shape is solved.

2) High efficiency, safe and convenient operation and control: since ion implantation can be performed simultaneously on a workpiece to which a pulsed negative potential is applied, large-area implantation can be achieved without scanning, and therefore, the efficiency is quite high. In addition, the ion implantation process can be conveniently controlled by adjusting the size of the pulse negative bias, the waveform and the frequency, and the operation is convenient.

3) Mass production: in the processing process, the cathode is the workpiece, and the plasma sheath layer around the workpiece is the anode, so that each workpiece and the plasma sheath layer around the workpiece form an independent ion implantation system, and the plasma-based ion implantation can realize batch production.

4) The production cost is reduced: because of the omnibearing ion implantation, the operations of reciprocation, rotation and the like required by the workpiece in the traditional ion implantation process can be omitted, so that the implantation equipment does not need a complex rotating target table and an ion beam scanning device. In addition, the production efficiency is high, and the mass production can be realized, so that the total production cost is greatly reduced compared with the traditional ion implantation technology.

The present invention will be described in further detail with reference to examples.