Stainless steel substrate surface strengthening treatment process and application thereof

Abstract

The present application relates to the technical field of C23C24 / 00, in particular to a stainless steel substrate surface strengthening treatment process and application thereof, at least comprising the following steps: at least comprising the following steps: (1) preparing a strengthening slurry by mixing the strengthening powder with the carrier; (2) spraying the strengthening slurry on the surface of the stainless steel substrate to obtain a workpiece to be treated; (3) placing the workpiece to be treated on a workbench, controlling the laser output power and scanning conditions to perform laser scanning treatment, and naturally cooling for 3-5 min, so as to achieve the formation of a nickel-titanium alloy layer on the surface of the stainless steel substrate by optimizing the strengthening slurry formula and treatment process, thereby improving the physical properties of the stainless steel substrate to meet the actual application requirements in different fields such as kitchen utensils, molds, cutting knives and even steel mill rollers, while almost not changing the size of the workpiece, the operation is simple, the process is pollution-free, green and environmentally friendly, and easy to realize industrial production.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of C23C24 / 00, in particular to a surface strengthening treatment process for a stainless steel base material and application thereof. BACKGROUND

[0002] The roller is the main equipment for conveying rolled pieces in a steel rolling workshop, and the roller is used for rolling the rolled pieces into the heating furnace, reciprocating rolling on the rolling mill and conveying the rolled pieces to the finishing process. The roller is an important part of the steel rolling mill, and in the process of rolling steel, the pressure generated by the rolling of a pair or a group of rollers is used to roll the steel. It mainly bears the dynamic and static load during rolling, wear and the influence of temperature change, so the material quality is very high. However, the cost of meeting the above-mentioned needs on the market is very high, so the prior art meets the above-mentioned use needs by surface strengthening of stainless steel.

[0003] Hardening treatment is usually used on the surface of stainless steel metal materials to improve the hardness, wear resistance, corrosion resistance and fatigue resistance of the metal material surface. Solid solution treatment is to heat the stainless steel metal to about 1000 DEG C, dissolve various precipitates such as nanometer carbide and chromium carbide in the metal under high temperature conditions, and then rapidly cool by water quenching or gas cooling, so as to improve the stability of the crystal. The hardness after solid solution heat treatment can reach HRC50-60. However, this process has obvious shortcomings. First, the processing difficulty is relatively large, and the heating temperature needs to be very accurate to achieve the ideal effect. Second, the surface of the stainless steel after solid solution treatment is easy to be contaminated, which destroys the passivation layer on the surface and greatly affects the corrosion resistance. Third, the high processing energy consumption leads to high processing cost. Stainless steel electroplating is to preplate a layer of copper or nickel on the surface of the stainless steel after pickling activation, increase the surface adhesion and gloss, and then electroplated with chromium or other metal plating layer. This process is complex, the processing time is long, and the most important is that it will produce serious chemical pollution source. The electric spark surface strengthening process is to apply high-energy electric pulse to the metal surface to produce local overheating, evaporation and ionization, form oxide and metal-rich layer, and thus enhance the hardness and wear resistance of the metal surface. For example, Chinese patent application (publication number CN116479338A) discloses an alloy steel and a surface strengthening process thereof. The service life and fatigue strength of the alloy steel after shot blasting treatment can be obviously improved, and the alloy steel can be regularly expanded due to the deposition of the electrode material through the electric spark surface treatment. However, the processing efficiency of this process is relatively low, and metamorphic layer and even microcracks are easy to appear, which is mainly applied to the processing of small workpieces and complex shape surfaces. SUMMARY

[0004] In order to solve the above problems, the present application optimizes the reinforced slurry formula and processing technology, so that the provided processing technology can perform surface strengthening treatment on the stainless steel substrate, so as to meet the actual application requirements of the steel mill roller, improve the production efficiency, prolong the service life, reduce the comprehensive production cost, and has extremely high application and popularization value.

[0005] In one aspect, the present application provides a surface strengthening treatment process for a stainless steel substrate, which at least comprises the following steps:

[0006] (1) mixing the reinforced powder with the carrier to prepare a reinforced slurry;

[0007] (2) spraying the reinforced slurry on the surface of the stainless steel substrate to obtain a workpiece to be treated;

[0008] (3) placing the workpiece to be treated on a workbench, controlling the laser output power and scanning conditions to perform laser scanning treatment, and naturally cooling for 3-5 minutes.

[0009] The preparation process provided by the present application realizes the formation of a nickel-titanium alloy layer on the surface of the stainless steel substrate by laser pressure infiltration, so as to improve the physical properties of the stainless steel substrate to meet the actual application requirements in different fields such as kitchen utensils, molds, cutting knives and even steel mill rollers, while almost not changing the size of the workpiece, simple operation, pollution-free and green process, easy to realize industrial production.

[0010] As a preferred technical solution, the reinforced powder at least comprises nano-carbide, nano-alloy powder and nano-oxide powder, and the particle size of the nano-carbide, nano-alloy powder and nano-oxide powder is 50-100 nm, preferably 50 nm.

[0011] Preferably, the reinforced powder comprises nano-carbide, nano-alloy powder 25-35%, and nano-oxide powder 1-5% by mass percentage.

[0012] Preferably, the nano-carbide is selected from at least one of nano-titanium carbide, nano-boron carbide, nano-molybdenum carbide, nano-niobium carbide, nano-zirconium carbide, nano-chromium carbide, nano-vanadium carbide and nano-cerium carbide, and is preferably a combination of nano-titanium carbide and nano-boron carbide.

[0013] Preferably, the nano-alloy powder is selected from at least one of nano-chromium powder, nano-nickel powder, nano-molybdenum powder and nano-cobalt powder, and is preferably a combination of nano-chromium powder, nano-nickel powder, nano-molybdenum powder and nano-cobalt powder.

[0014] Preferably, the nano-oxide powder is selected from at least one of nano-aluminum oxide powder, nano-silicon oxide powder and nano-molybdenum oxide powder, and is preferably nano-aluminum oxide powder.

[0015] The reinforcing powder comprises, by mass percentage, 38-42% of titanium carbide, 28-32% of boron carbide, 6-8% of nano-chromium powder, 10-12% of nano-nickel powder, 2-4% of nano-molybdenum powder, 6-8% of nano-cobalt powder, and 2% of nano-alumina powder.

[0016] Most preferably, the reinforcing powder comprises, by mass percentage, 40% of titanium carbide, 30% of boron carbide, 7% of nano-chromium powder, 11% of nano-nickel powder, 3% of nano-molybdenum powder, 7% of nano-cobalt powder, and 2% of nano-alumina powder.

[0017] Preferably, the carrier is ethanol, and the mass ratio of the reinforcing powder to the carrier is 1:(8-15).

[0018] Preferably, the spraying amount is 0.2-0.3mm in covering the surface layer of the stainless steel substrate.

[0019] The reinforcing treatment process provided by the application forms a nickel-titanium alloy layer by optimizing the combination of the reinforcing powder, i.e., titanium carbide, boron carbide, nano-chromium powder, nano-nickel powder, nano-molybdenum powder, nano-cobalt powder, and nano-alumina powder, and performing laser scanning treatment, and realizes metallurgical bonding with the stainless steel substrate, thereby forming a high-thickness nickel-titanium alloy layer under a low reinforcing powder addition amount and having a long service life under actual application conditions of high temperature, high extrusion pressure, and high friction. The inventor analyzes the reason as follows: the above nano-powder interacts under the irradiation of a high-energy laser beam, penetrates the surface layer of the stainless steel substrate in a micro-melt state, and forms a high-thickness remelted zone after cooling, thereby endowing the stainless steel substrate with excellent extrusion resistance, high-temperature resistance, and friction resistance, and meeting the hardness and wear resistance requirements in actual application.

[0020] As a preferred technical solution, the laser output power is 2000-3000W, preferably 2800-3000W.

[0021] As a preferred technical solution, the scanning conditions are as follows: the scanning spot of the robot arm is 2x(10-20)mm, the scanning speed of the robot arm is 500-1000mm / min, and the laser focal length of the robot arm is 25-28cm. Preferably, the scanning conditions are as follows: the scanning spot of the robot arm is 2x20mm, the scanning speed of the robot arm is 580-600mm / min, and the laser focal length of the robot arm is 25-26cm.

[0022] In the application, the fiber laser complete custom assembly equipment is used to spray the stainless steel substrate with the reinforced slurry to realize the laser scanning treatment, so that the reinforced powder is combined with the stainless steel substrate, and the size change of the substrate is negligible. The inventors found that, on the basis of optimizing the composition of the reinforced powder, further cooperating with the corresponding laser output power and scanning conditions, the thickness of the nickel-titanium alloy layer is significantly increased to 0.05-0.15 mm, the Vickers hardness HV0.2 of the laser permeation surface nickel-titanium alloy layer is above 1500, and the hardness, wear resistance and extrusion impact resistance are extremely high. The inventors analyzed the reasons, which may be that under the impact of the high-energy laser beam of 2800-3000W, titanium carbide, boron carbide, nano-chromium powder, nano-nickel powder, nano-molybdenum powder, nano-cobalt powder and nano-alumina powder are melted and subjected to high-temperature and high-pressure extrusion to penetrate into the stainless steel substrate surface, and the powders interact and perform lattice filling and crystallization to form a relatively thick laser permeation surface nickel-titanium alloy layer.

[0023] Another aspect of the application provides an application of a stainless steel substrate surface strengthening treatment process, which is applied to the preparation of the laser permeation surface nickel-titanium alloy layer of the stainless steel substrate.

[0024] Advantages

[0025] 1. The application optimizes the reinforced slurry formula and the treatment process, so that the provided treatment process can perform surface strengthening treatment on the stainless steel substrate, meet the actual application requirements of the steel mill roller, improve the production efficiency, prolong the service life, reduce the comprehensive production cost, and has extremely high application and promotion value.

[0026] 2. The preparation process provided by the application realizes the formation of a nickel-titanium alloy layer on the surface of the stainless steel substrate by laser permeation, so as to improve the physical properties of the stainless steel substrate to meet the actual application requirements of kitchen utensils, molds, cutting knives and even steel mill rollers in different fields, while almost not changing the workpiece size, the operation is simple, the process is pollution-free, green and environmentally friendly, and industrial production is easy to realize.

[0027] 3. The strengthening treatment process provided by the application optimizes the combination of the reinforced powder, i.e. titanium carbide, boron carbide, nano-chromium powder, nano-nickel powder, nano-molybdenum powder, nano-cobalt powder and nano-alumina powder, and forms a nickel-titanium alloy layer after laser scanning treatment, so as to realize metallurgical combination with the stainless steel substrate, form a high-thickness nickel-titanium alloy layer under a low reinforced powder addition amount, and have a long service life under the actual application conditions of high temperature, high extrusion pressure and high friction.

[0028] 4. In the application, the fiber laser complete custom assembly equipment is used to spray the stainless steel substrate with the reinforced slurry to realize the laser scanning treatment, so that the reinforced powder is combined with the stainless steel substrate, and the size change of the substrate is negligible.

[0029] 5. The stainless steel substrate surface strengthening process provided by the present invention, based on the optimization of the strengthening powder composition, further combines the corresponding laser output power and scanning conditions to significantly increase the thickness of the nickel-titanium alloy layer to 0.05-0.15mm. The Vickers hardness HV0.2 of the laser-impregnated surface nickel-titanium alloy layer is above 1500, which has extremely high hardness, wear resistance and extrusion impact resistance. Attached Figure Description

[0030] Figure 1 The image shows a cross-sectional metallographic image of the laser-impregnated surface titanium alloy layer formed on a 316 stainless steel substrate after processing in Example 1 of the present invention. The image is labeled as the laser-impregnated surface titanium alloy layer. Detailed Implementation

[0031] Example 1

[0032] Embodiment 1 of the present invention provides a surface strengthening treatment process for a stainless steel substrate, comprising the following steps:

[0033] (1) Prepare a reinforced slurry by mixing the reinforced powder with the carrier;

[0034] (2) The reinforcing slurry is sprayed onto the surface of the stainless steel substrate to obtain the workpiece to be treated;

[0035] (3) Place the workpiece to be processed on the worktable, control the laser output power and scanning conditions to perform laser scanning processing, and allow it to cool naturally for 3 minutes.

[0036] The stainless steel substrate is 316 stainless steel.

[0037] The reinforced powder is composed of nano-carbide, nano-alloy powder, and nano-oxide powder, and the particle size of the nano-carbide, nano-alloy powder, and nano-oxide powder is 50 nm.

[0038] The nanocarbide is a combination of nano-titanium carbide and nano-boron carbide.

[0039] The nano-alloy powder is a combination of nano-chromium powder, nano-nickel powder, nano-molybdenum powder, and nano-cobalt powder.

[0040] The nano-oxide powder is nano-alumina powder.

[0041] The reinforcing powder comprises, by weight percentage: 40% titanium carbide, 30% boron carbide, 7% nano chromium powder, 11% nano nickel powder, 3% nano molybdenum powder, 7% nano cobalt powder, and 2% nano alumina powder.

[0042] The carrier is ethanol, and the mass ratio of the reinforced powder to the carrier is 1:12.

[0043] The spraying amount is 0.3mm of the surface layer of the stainless steel base material.

[0044] The laser output power is 3000W.

[0045] The scanning condition is that the scanning spot of the robot arm is 2*20mm, the scanning speed of the robot arm is 600mm / min, and the laser focal length of the robot arm is 26cm.

[0046] The fiber laser complete customized assembly equipment (from Wuhan Walton Laser Technology Co., Ltd.) is used to perform laser scanning treatment on the stainless steel base material sprayed with the reinforcing slurry.

[0047] The embodiment 1 of the present application further provides an application of the surface reinforcing treatment process of the stainless steel base material, which is applied to preparation of the laser pressure infiltration surface nickel-titanium alloy layer of the stainless steel base material, and the thickness of the laser pressure infiltration surface nickel-titanium alloy layer is 0.15mm.

[0048] Embodiment 2

[0049] The embodiment 2 of the present application provides a surface reinforcing treatment process of a stainless steel base material and an application thereof, and the specific implementation manner is the same as that of the embodiment 1, and the difference lies in that the stainless steel base material is a 304 stainless steel base material.

[0050] Embodiment 3

[0051] The embodiment 3 of the present application provides a surface reinforcing treatment process of a stainless steel base material and an application thereof, and the specific implementation manner is the same as that of the embodiment 1, and the difference lies in that the reinforcing powder comprises, in percentage by mass, 38% of titanium carbide, 32% of boron carbide, 6% of nano-chromium powder, 12% of nano-nickel powder, 4% of nano-molybdenum powder, 6% of nano-cobalt powder and 2% of nano-alumina powder, and the laser output power is 2800W.

[0052] Embodiment 4

[0053] The embodiment 4 of the present application provides a surface reinforcing treatment process of a stainless steel base material and an application thereof, and the specific implementation manner is the same as that of the embodiment 1, and the difference lies in that the reinforcing powder comprises, in percentage by mass, 42% of titanium carbide, 28% of boron carbide, 8% of nano-chromium powder, 10% of nano-nickel powder, 2% of nano-molybdenum powder, 8% of nano-cobalt powder and 2% of nano-alumina powder, and the scanning condition is that the scanning spot of the robot arm is 2*20mm, the scanning speed of the robot arm is 580mm / min, and the laser focal length of the robot arm is 25cm.

[0054] Comparative Example 1

[0055] The comparative example 1 of the present application provides a surface strengthening treatment process of a stainless steel substrate and its application, and the specific implementation is the same as the example 1, except that the laser output power is 1500 W, and the scanning conditions are that the scanning spot of the robot arm is 2*10 mm, the scanning speed of the robot arm is 400 mm / min, and the laser focal length of the robot arm is 20 cm.

[0056] Comparative example 2

[0057] The comparative example 2 of the present application provides a surface strengthening treatment process of a stainless steel substrate and its application, and the specific implementation is the same as the example 1, except that the strengthening powder comprises, by mass percentage, titanium carbide 30%, boron carbide 30%, nano-chromium powder 8%, nano-nickel powder 12%, nano-molybdenum powder 4%, nano-cobalt powder 6%, and nano-alumina powder 10%.

[0058] Performance test method

[0059] (1) Hardness: the Vickers hardness HV0.2 of the laser permeation surface nickel-titanium alloy layer formed after the treatment of the example and the comparative example is tested by using a WHV-1MDT automatic turret digital display micro Vickers hardness tester, the test result is the average value of 5 times, and is recorded in Table 1.

[0060] (2) The structural characteristics of the laser permeation surface nickel-titanium alloy layer formed after the treatment of the example and the comparative example are observed by using a DMI8-C Leica metallographic microscope (100 times magnification) (see Table 1). Figure 1

[0061] Table 1

[0062]

[0063]

[0064] (3) Service life: the cold bending roller prepared after the product is treated by using the process provided in the example 1 of the present application is used to produce cross-lift products (J152.4*101.6*4.78 J152.4*76.2*4.78, a total of 103.055 tons), sharp J160*100*5, sharp J140*100*5 J100*50*5, F76*5, and the like, a total of 1038.127 tons, and the surface quality still maintains a good state and can be further used.​

Claims

1. A process for surface strengthening of a stainless steel substrate, characterized by, At least comprising the following steps: (1) preparing a reinforced slurry after mixing the reinforced powder with the carrier; (2) spraying the reinforced slurry on the surface of the stainless steel substrate to obtain a workpiece to be treated; (3) placing the workpiece to be treated on a workbench, controlling the laser output power and scanning conditions for laser scanning treatment, and naturally cooling for 3-5 min; According to the mass percentage, the reinforced powder comprises: titanium carbide 38-42%, boron carbide 28-32%, nano-chromium powder 6-8%, nano-nickel powder 10-12%, nano-molybdenum powder 2-4%, nano-cobalt powder 6-8%, and nano-alumina powder 2%; the carrier is ethanol, the mass ratio of the reinforced powder to the carrier is 1:(8-15); the laser output power is 2000-3000 W; the scanning conditions are: the scanning spot of the robot arm is 2×(10-20) mm, the scanning speed of the robot arm is 500-1000 mm / min, and the laser focal length of the robot arm is 25-28 cm.

2. Use of a process for surface hardening of stainless steel substrates according to claim 1, characterized in that, It is applied to the preparation of a laser pressure infiltration surface nickel-titanium alloy layer on the surface of a stainless steel substrate.

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