Preparation method of high zinc-repellent carbon steel and zinc-repellent performance testing method

Abstract

The application discloses a preparation method of high-surface zinc-repellent carbon steel and a zinc-repellent performance testing method, and belongs to the technical field of zinc-repellent treatment of hot-dip galvanizing technology. The preparation method comprises material pretreatment, siliconizing agent preparation, silicide coating preparation and high-temperature pre-oxidation treatment. The zinc-repellent performance testing method comprises zinc liquid immersion test, high-temperature wetting angle test and high-temperature rolling angle test. The preparation method of high-surface zinc-repellent carbon steel and the zinc-repellent performance testing method are simple in process, low in cost, uniform and dense in prepared siliconizing coating, small in adhesion of a low-surface-energy functional layer after pre-oxidation treatment, can accurately and intuitively test the zinc-repellent performance of different carbon steel surfaces through the three testing methods, are widely used, and are suitable for large-scale industrial production and popularization and use.

Description

Technical Field

[0001] This invention belongs to the technical field of zinc-repellent treatment in hot-dip galvanizing technology, and relates to a method for preparing carbon steel with high surface zinc-repellent properties and a method for testing zinc-repellent properties. Background Technology

[0002] 15-20% of the annual losses due to corrosion can be mitigated through protective measures. Hot-dip galvanizing is a widely adopted protective measure for steel corrosion protection, particularly in the power industry, primarily for transmission towers and other structures.

[0003] However, during the hot-dip galvanizing process, the zinc solution easily adheres to the racking equipment (carbon steel), resulting in zinc solution loss and increased production costs. Furthermore, the zinc solution can corrode carbon steel, affecting its service life. Therefore, researching methods to improve the zinc-repellent properties of carbon steel is crucial.

[0004] Current research suggests methods to improve the zinc-repellent properties of carbon steel, such as boron embedding and thermal spraying. While these methods can improve the zinc-repellent properties of carbon steel, the boron compound coatings prepared on the carbon steel surface by boron embedding are brittle and prone to cracking; thermal spraying, due to its porosity, results in a non-dense coating with low bonding strength to the carbon steel substrate, poor thermal shock resistance, and easy peeling, thus the zinc-repellent effect is not ideal.

[0005] The journal article "The Influence of Carbon and Silicon Content on the Morphology of Corrosion Layer in Carbon Steel" (Li Deyuan, Wang Heying, Ma Jun) disclosed that when the silicon content in steel is high, the iron-zinc reaction rate will be accelerated, and abnormal growth of corrosion layer structure will occur. Obviously, if a surface coating is to be prepared, the addition of silicon-containing elements should be avoided as much as possible.

[0006] Chinese patent CN112899509A discloses a composite material resistant to molten zinc corrosion, its preparation method, and equipment. The composite material includes FeB, W, and AlFeNiCoCr in mass percentages of 68-78%, 10-20%, and 12%, respectively. Obviously, the composition of the composite material is complex, the preparation cost is high, and it is difficult to predict whether it can be used to prepare a coating for carbon steel.

[0007] Chinese patent CN108642431A discloses a metal-ceramic coating / powder resistant to molten zinc corrosion and its preparation method, as well as a submerged roller. The preparation method of the metal-ceramic coating includes pulverizing FeB alloy powder and Al... 0.25 Preparation of FeNiCoCr high-entropy alloy binder phase, Al 0.25 The preparation of the mixed powder of FeNiCoCr high-entropy alloy binder phase and FeB hard phase and the AC-HVAF spraying process obviously involves complex composition of the metal ceramic coating, high preparation cost, and it is difficult to predict whether it can be used to prepare carbon steel surface coatings. Summary of the Invention

[0008] The technical problem to be solved by the present invention is how to overcome the fact that carbon steel is not resistant to molten zinc corrosion in the prior art, and that the molten zinc corrosion resistance of carbon steel obtained by methods such as embedding boronizing treatment and thermal spraying is not good. The cost of preparing composite materials or metal ceramic coatings / powders resistant to molten zinc corrosion is high, and it is difficult to expect them to be used to prepare carbon steel surface coatings and coating preparation methods, which is not conducive to large-scale industrial production.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0010] A method for preparing carbon steel with high surface zinc-repellent properties, the method comprising the following steps:

[0011] S1, Material Pretreatment

[0012] The carbon steel is sequentially ground, polished, ultrasonically cleaned, and dried to obtain the pretreated carbon steel material.

[0013] S2, Preparation of Silicate Infiltrating Agent

[0014] The silicon-supplying agent, filler, thermal conductive agent, and infiltration catalyst are weighed and prepared according to the silicon-infiltrating agent ratio, and then ground evenly to obtain the silicon-infiltrating agent product.

[0015] S3, Preparation of silicide coating

[0016] The pretreated carbon steel material from step S1 and the silicon infiltrating agent from step S2 are placed in a crucible at the same time, and the silicon infiltrating agent is uniformly covered on the surface of the pretreated carbon steel material; then the crucible is placed in a muffle furnace for heat treatment to obtain silicon-infiltrated carbon steel material with a silicide coating on the surface.

[0017] S4, High-temperature pre-oxidation treatment

[0018] The silicon-dipped carbon steel material in step S3 is ultrasonically cleaned and dried, and then pre-oxidized in high-temperature static air to obtain carbon steel with high surface zinc-repellent properties.

[0019] Preferably, in step S1, grinding is performed using 120-1200# sandpaper, polishing is performed using 1.5-2.5μm diamond polishing paste, and ultrasonic cleaning is performed using anhydrous ethanol added to an ultrasonic cleaner.

[0020] Preferably, in step S2, the silicon infiltration agent consists of 30-45 wt.% silicon supply agent, 1 wt.% silicon infiltration catalyst, 54-69 wt.% filler and thermal conductive agent.

[0021] Preferably, in step S2, the silicon-supplying agent is at least one of ferrosilicon powder and silicon powder, the penetration catalyst is at least one of sodium fluoride, ammonium fluoride, and ammonium chloride, the filler is high-temperature α-alumina, and the thermal conductive agent is diamond sand.

[0022] Preferably, in step S2, the silicating agent, filler, and thermal conductive agent in the silicating agent are all 100-200 mesh.

[0023] Preferably, in step S3, the simultaneous placement in the crucible is as follows: 15-20 mm of siliconizing agent is placed at the top and bottom of the crucible, with a 10-15 mm gap between the carbon steel pieces; finally, the crucible is sealed with high-temperature adhesive and water glass, and after sealing, it is placed in a muffle furnace for heat treatment.

[0024] Preferably, in step S3, the heat treatment is as follows: heating temperature 950-1050℃, holding time 5-10h, heating rate 3-8℃ / min, and finally cooling to room temperature with the furnace.

[0025] Preferably, in step S4, the temperature of the high-temperature static air is 950-1000℃, and the pre-oxidation treatment time is 5-10h.

[0026] Preferably, in step S3, the surface of the silicon-diffused carbon steel material is grayish-white, the density of the silicide coating on the carbon steel surface is 91-96%, the composition of the silicide coating is Fe3Si and FeSi, and the size is 40-71μm; in step S4, the surface of the carbon steel with high surface zinc-repellent properties is black, the density of the silicide coating on the carbon steel surface is 94-99%, the composition of the silicide coating is Fe2O3 and SiO2, and the size is 55-91μm.

[0027] Preferably, in step S4, the surface of the siliconized carbon steel after high-temperature pre-oxidation is smooth and flat, and the silicide coating on the carbon steel surface undergoes selective oxidation to form a low surface energy SiO2 oxide film. The low surface energy SiO2 oxide film effectively prevents the adhesion and diffusion of Zn in the molten Zn liquid.

[0028] A method for testing the zinc-repellent properties of high-surface zinc-repellent carbon steel obtained based on the aforementioned preparation method, the zinc-repellent property testing method comprising the following steps:

[0029] SS1, Zinc immersion test

[0030] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. Several zinc blocks were placed in a muffle furnace and heated to melt into molten zinc. Then, the aforementioned three different types of carbon steel were placed in the molten zinc and kept at a certain temperature. After the holding time was completed, the adhesion ability V of the molten zinc to the carbon steel was calculated according to the following formula. zn :

[0031]

[0032] Where: V zn >0, unit is mg / cm³ 2 •h; m1 is the mass of carbon steel before immersion, m2 is the mass of carbon steel after immersion, both in mg; s is the surface area of ​​carbon steel in cm². 2 t represents the soaking time, in hours (h).

[0033] SS2, High-temperature wetting angle test

[0034] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. A zinc block was placed at the center of each of the three different carbon steels, followed by vacuuming and image acquisition. The zinc block was then heated to melt it into molten zinc, and the mixture was kept at that temperature until the Zn metal no longer spread. The furnace was then cooled. The wetting angle θ of the molten zinc on the three different carbon steels was calculated using the following formula:

[0035]

[0036] Where: h is the height of the zinc liquid around the carbon steel, in mm; d is the contact length of the carbon steel, in mm;

[0037] SS3, High-Temperature Roll Angle Test

[0038] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. Then, they were placed on a high-temperature roll-off angle measuring instrument. Zinc liquid was then dripped onto the surface of the three different carbon steels using the instrument. The measuring instrument was slowly rotated until the zinc liquid just rolled off the surface of the three different carbon steels. The roll-off angle α of the three different carbon steels was then read and recorded. The roll-off angle of each group of three different carbon steels was measured more than three times, and the average value was taken as the final high-temperature roll-off angle of the three different carbon steels.

[0039] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0040] This invention employs an embedded silicon-infiltrating chemical surface heat treatment technique to prepare a silicide coating on the surface of carbon steel. The surface of the silicon-infiltrating carbon steel material is grayish-white, and the density of the silicide coating on the carbon steel surface is 91-96%. The composition of the silicide coating is Fe3Si and FeSi, and the size is 40-71μm.

[0041] This invention uses a high-temperature pre-oxidation test to treat silicon-diffused carbon steel. The surface of the carbon steel with high surface zinc-repellent properties is black, and the density of the silicide coating on the carbon steel surface is 94-99%. The composition of the silicide coating is Fe2O3 and SiO2, and the size is 55-91μm.

[0042] This invention employs zinc immersion tests, high-temperature wetting angle tests, and high-temperature rolling angle tests to comprehensively test the zinc-repellent properties of material surfaces. The methods are simple and convenient, and the adhesion ability of zinc immersion to carbon steel on different material surfaces is measured (V). zn The comparison of wetting angle and roll-off angle can accurately and intuitively test the comprehensive zinc-repellent properties of different surfaces.

[0043] The zinc immersion test, high-temperature wetting angle test, and high-temperature rolling angle test of this invention provide a comprehensive test of the zinc-repellent properties of the material surface with an accuracy rate of 98%. The adhesion of the low surface energy functional layer after pre-oxidation treatment is 0.29-0.63 mg / cm². 2 ·h.

[0044] In summary, the present invention provides a method for preparing carbon steel with high surface zinc-repellent properties and a method for testing zinc-repellent properties. The process is simple and low-cost. The prepared silicon-infiltrated coating is uniform and dense. After pre-oxidation treatment, the low surface energy functional layer has low adhesion. Through the three assessment methods designed in this invention, the zinc-repellent properties of different carbon steel surfaces can be accurately and intuitively tested. It has a wide range of applications and is suitable for large-scale industrial production and widespread use. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a process flow diagram of the method for preparing carbon steel with high surface zinc-repellent properties according to the present invention;

[0047] Figure 2 This is a process flow diagram of the zinc-repellent performance testing method for high surface zinc-repellent carbon steel according to the present invention;

[0048] Figure 3 This is a schematic diagram of the method for preparing the silicide coating in step S3 of the method for preparing carbon steel with high surface zinc-repellent properties according to the present invention.

[0049] Figure 4 These are comparative photographs of the carbon steel without material pretreatment in step S1 of Embodiment 3 of the present invention, the carbon steel after silicon infiltration in step S3, and the carbon steel with high surface zinc-repellent properties obtained in step S4, showing the surface zinc-repellent properties of the carbon steel after full immersion zinc-repellent testing. Detailed Implementation

[0050] The technical solutions and problems solved by the embodiments of the present invention will be described below with reference to the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them.

[0051] Example 1

[0052] A method for preparing carbon steel with high surface zinc-repellent properties, the method being as follows: Figure 1 The steps shown are as follows:

[0053] S1, Material Pretreatment

[0054] The carbon steel is subjected to grinding, polishing, ultrasonic cleaning and drying in sequence. Grinding is performed by surface grinding with 120-1200# sandpaper, polishing is performed by surface polishing with 1.5-2.5μm diamond polishing paste, and ultrasonic cleaning is performed by surface cleaning with anhydrous ethanol added to an ultrasonic cleaner to obtain pretreated carbon steel material.

[0055] S2, Preparation of Silicate Infiltrating Agent

[0056] The silicon-supplying agent, filler, thermally conductive agent, and infiltration catalyst are weighed and prepared according to the silicon-infiltrating agent ratio, and then ground evenly to obtain the silicon-infiltrating agent product. The silicon-infiltrating agent consists of 30 wt.% silicon-supplying agent, 1 wt.% infiltration catalyst, 69 wt.% filler, and thermally conductive agent. The silicon-supplying agent, filler, and thermally conductive agent in the silicon-infiltrating agent are all 100-200 mesh. The silicon-supplying agent is 49 wt.% ferrosilicon powder, the infiltration catalyst is at least one of sodium fluoride, ammonium fluoride, and ammonium chloride, the filler is 20 wt.% high-temperature α-alumina, and the thermally conductive agent is diamond sand.

[0057] S3, Preparation of silicide coating

[0058] The pretreated carbon steel material from step S1 and the silicon infiltrating agent from step S2 are simultaneously placed in a crucible. 20mm of silicon infiltrating agent is placed at the top and bottom of the crucible, with a 15mm gap between the carbon steel pieces. The crucible is then sealed with high-temperature adhesive and water glass. After sealing, it is placed in a muffle furnace for heat treatment at a temperature of 1050℃, a holding time of 6 hours, and a heating rate of 3℃ / min. Finally, it is cooled to room temperature with the furnace to obtain silicon-infiltrated carbon steel material with a silicide coating. The surface of the silicon-infiltrated carbon steel material is grayish-white, and the density of the silicide coating on the carbon steel surface is 91%. The composition of the silicide coating is Fe3Si and FeSi, with a size of 40μm.

[0059] S4, High-temperature pre-oxidation treatment

[0060] The silicon-diffused carbon steel material in step S3 is ultrasonically cleaned for 10 minutes and dried. Then, it undergoes pre-oxidation treatment in high-temperature static air, wherein the temperature of the high-temperature static air is 950℃ and the pre-oxidation treatment time is 10 hours, to obtain carbon steel with high surface zinc-repellent properties. The surface of the carbon steel with high surface zinc-repellent properties is black, and the density of the silicide coating on the carbon steel surface is 94%. The composition of the silicide coating is Fe2O3 and SiO2, and the size is 55μm.

[0061] The prepared high-temperature pre-oxidized siliconized carbon steel has a smooth and flat surface, and the silicide coating on the carbon steel surface undergoes selective oxidation to form a low surface energy SiO2 oxide film. The low surface energy SiO2 oxide film effectively prevents the adhesion and diffusion of Zn in the molten Zn liquid.

[0062] A method for testing the zinc-repellent properties of high-surface zinc-repellent carbon steel obtained based on the preparation method of this embodiment, wherein the zinc-repellent property testing method is as follows: Figure 2 The steps shown are as follows:

[0063] SS1, Zinc immersion test

[0064] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. Several zinc blocks were placed in a muffle furnace and heated to melt into molten zinc. Then, the aforementioned three different types of carbon steel were placed in the molten zinc and kept at a certain temperature. After the holding time was completed, the adhesion ability V of the molten zinc to the carbon steel was calculated according to the following formula. zn :

[0065]

[0066] Where: V zn >0, unit is mg / cm³ 2 •h; m1 is the mass of carbon steel before immersion, m2 is the mass of carbon steel after immersion, both in mg; s is the surface area of ​​carbon steel in cm². 2 t represents the soaking time, in hours (h).

[0067] SS2, High-temperature wetting angle test

[0068] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. A zinc block was placed at the center of each of the three different carbon steels, followed by vacuuming and image acquisition. The zinc block was then heated to melt it into molten zinc, and the mixture was kept at that temperature until the Zn metal no longer spread. The furnace was then cooled. The wetting angle θ of the molten zinc on the three different carbon steels was calculated using the following formula:

[0069]

[0070] Where: h is the height of the zinc liquid around the carbon steel, in mm; d is the contact length of the carbon steel, in mm;

[0071] SS3, High-Temperature Roll Angle Test

[0072] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. Then, they were placed on a high-temperature roll-off angle measuring instrument. Zinc liquid was then dripped onto the surface of the three different carbon steels using the instrument. The measuring instrument was slowly rotated until the zinc liquid just rolled off the surface of the three different carbon steels. The roll-off angle α of the three different carbon steels was then read and recorded. The roll-off angle of each group of three different carbon steels was measured more than three times, and the average value was taken as the final high-temperature roll-off angle of the three different carbon steels.

[0073] The final results show the adhesion V of the zinc bath to carbon steel obtained from the following processes: carbon steel without material pretreatment in step S1, silicon-infiltrated carbon steel in step S3, and high surface zinc-repellent carbon steel obtained in step S4. zn The values ​​were 45.99 mg / cm³. 2 ·h, 1.12mg / cm 2 ·h, 0.62mg / cm 2 The high-temperature wetting angles are 36°, 110°, and 120°, and the high-temperature rolling angles are 86°, 46°, and 42°.

[0074] Table 1

[0075]

[0076] Example 2

[0077] A method for preparing carbon steel with high surface zinc-repellent properties, the method being as follows: Figure 1 The steps shown are as follows:

[0078] S1, Material Pretreatment

[0079] The carbon steel is subjected to grinding, polishing, ultrasonic cleaning and drying in sequence. Grinding is performed by surface grinding with 120-1200# sandpaper, polishing is performed by surface polishing with 1.5-2.5μm diamond polishing paste, and ultrasonic cleaning is performed by surface cleaning with anhydrous ethanol added to an ultrasonic cleaner to obtain pretreated carbon steel material.

[0080] S2, Preparation of Silicate Infiltrating Agent

[0081] The silicon-supplying agent, filler, thermally conductive agent, and infiltration catalyst are weighed and prepared according to the silicon-infiltrating agent ratio, and then ground evenly to obtain the silicon-infiltrating agent product. Among them, the silicon-infiltrating agent consists of 35 wt.% silicon-supplying agent, 1 wt.% infiltration catalyst, 64 wt.% filler and thermally conductive agent. The mesh size of silicon-supplying agent, filler and thermally conductive agent in silicon-infiltrating agent are all 100-200 mesh. The silicon-supplying agent is 35 wt.% ferrosilicon powder, the infiltration catalyst is at least one of sodium fluoride, ammonium fluoride and ammonium chloride, the filler is 54 wt.% high-temperature α-alumina, and the thermally conductive agent is 10 wt.% diamond sand.

[0082] S3, Preparation of silicide coating

[0083] The pretreated carbon steel material from step S1 and the silicon infiltrating agent from step S2 are simultaneously placed in a crucible. 20mm of silicon infiltrating agent is placed at the top and bottom of the crucible, with a 15mm gap between the carbon steel pieces. The crucible is then sealed with high-temperature adhesive and water glass. After sealing, it is placed in a muffle furnace for heat treatment at a temperature of 1050℃, a holding time of 6 hours, and a heating rate of 3℃ / min. Finally, it is cooled to room temperature with the furnace to obtain a silicon-infiltrated carbon steel material with a silicide coating. The surface of the silicon-infiltrated carbon steel material is grayish-white, and the density of the silicide coating on the carbon steel surface is 92%. The silicide coating consists of Fe3Si and FeSi, with a size of 51μm.

[0084] S4, High-temperature pre-oxidation treatment

[0085] The silicon-diffused carbon steel material in step S3 is ultrasonically cleaned and dried, and then pre-oxidized in high-temperature static air. The temperature of the high-temperature static air is 950°C, and the pre-oxidation time is 10 hours, to obtain carbon steel with high surface zinc-repellent properties. The surface of the carbon steel with high surface zinc-repellent properties is black, and the density of the silicide coating on the carbon steel surface is 95%. The composition of the silicide coating is Fe2O3 and SiO2, and the size is 68μm.

[0086] The prepared high-temperature pre-oxidized siliconized carbon steel has a smooth and flat surface, and the silicide coating on the carbon steel surface undergoes selective oxidation to form a low surface energy SiO2 oxide film. The low surface energy SiO2 oxide film effectively prevents the adhesion and diffusion of Zn in the molten Zn liquid.

[0087] A method for testing the zinc-repellent properties of high-surface zinc-repellent carbon steel obtained based on the preparation method of this embodiment, wherein the zinc-repellent property testing method is as follows: Figure 2 The steps shown are as follows:

[0088] SS1, Zinc immersion test

[0089] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. Several zinc blocks were placed in a muffle furnace and heated to melt into molten zinc. Then, the aforementioned three different types of carbon steel were placed in the molten zinc and kept at a certain temperature. After the holding time was completed, the adhesion ability V of the molten zinc to the carbon steel was calculated according to the following formula. zn :

[0090]

[0091] Where: V zn >0, unit is mg / cm³ 2 •h; m1 is the mass of carbon steel before immersion, m2 is the mass of carbon steel after immersion, both in mg; s is the surface area of ​​carbon steel in cm². 2 t represents the soaking time, in hours (h).

[0092] SS2, High-temperature wetting angle test

[0093] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. A zinc block was placed at the center of each of the three different carbon steels, followed by vacuuming and image acquisition. The zinc block was then heated to melt it into molten zinc, and the mixture was kept at that temperature until the Zn metal no longer spread. The furnace was then cooled. The wetting angle θ of the molten zinc on the three different carbon steels was calculated using the following formula:

[0094]

[0095] Where: h is the height of the zinc liquid around the carbon steel, in mm; d is the contact length of the carbon steel, in mm;

[0096] SS3, High-Temperature Roll Angle Test

[0097] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. Then, they were placed on a high-temperature roll-off angle measuring instrument. Zinc liquid was then dripped onto the surface of the three different carbon steels using the instrument. The measuring instrument was slowly rotated until the zinc liquid just rolled off the surface of the three different carbon steels. The roll-off angle α of the three different carbon steels was then read and recorded. The roll-off angle of each group of three different carbon steels was measured more than three times, and the average value was taken as the final high-temperature roll-off angle of the three different carbon steels.

[0098] The final results show the adhesion V of the zinc bath to carbon steel obtained from the following processes: carbon steel without material pretreatment in step S1, silicon-infiltrated carbon steel in step S3, and high surface zinc-repellent carbon steel obtained in step S4. zn 45.96 mg / cm2 ·h, 0.92mg / cm 2 ·h, 0.52mg / cm 2 The high-temperature wetting angles are 36°, 117°, and 126°, respectively, and the high-temperature rolling angles are 86°, 40°, and 38°, respectively.

[0099] Table 2

[0100]

[0101] Example 3

[0102] A method for preparing carbon steel with high surface zinc-repellent properties, the method being as follows: Figure 1 The steps shown are as follows:

[0103] S1, Material Pretreatment

[0104] The carbon steel is subjected to grinding, polishing, ultrasonic cleaning and drying in sequence. Grinding is performed by surface grinding with 120-1200# sandpaper, polishing is performed by surface polishing with 1.5-2.5μm diamond polishing paste, and ultrasonic cleaning is performed by surface cleaning with anhydrous ethanol added to an ultrasonic cleaner to obtain pretreated carbon steel material.

[0105] S2, Preparation of Silicate Infiltrating Agent

[0106] The silicon-supplying agent, filler, thermally conductive agent, and infiltration catalyst are weighed and prepared according to the silicon-infiltrating agent ratio, and then ground evenly to obtain the silicon-infiltrating agent product. The silicon-infiltrating agent consists of 40 wt.% silicon-supplying agent, 1 wt.% infiltration catalyst, 59 wt.% filler, and thermally conductive agent. The silicon-supplying agent, filler, and thermally conductive agent in the silicon-infiltrating agent are all 100-200 mesh. The silicon-supplying agent is ferrosilicon powder, the infiltration catalyst is at least one of sodium fluoride, ammonium fluoride, and ammonium chloride, the filler is 34 wt.% high-temperature α-alumina, and the thermally conductive agent is 25 wt.% diamond sand.

[0107] S3, Preparation of silicide coating

[0108] The pretreated carbon steel material from step S1 and the silicon infiltrating agent from step S2 are simultaneously placed in a crucible. 20mm of silicon infiltrating agent is placed at the top and bottom of the crucible, with a 15mm gap between the carbon steel pieces. The crucible is then sealed with high-temperature adhesive and water glass. After sealing, it is placed in a muffle furnace for heat treatment at a temperature of 1050℃, a holding time of 6 hours, and a heating rate of 3℃ / min. Finally, it is cooled to room temperature with the furnace to obtain silicon-infiltrated carbon steel material with a silicide coating. The surface of the silicon-infiltrated carbon steel material is grayish-white, and the density of the silicide coating on the carbon steel surface is 94%. The composition of the silicide coating is Fe3Si and FeSi, with a size of 61μm.

[0109] S4, High-temperature pre-oxidation treatment

[0110] The silicon-diffused carbon steel material in step S3 is ultrasonically cleaned and dried, and then pre-oxidized in high-temperature static air. The temperature of the high-temperature static air is 950°C, and the pre-oxidation time is 10 hours, to obtain carbon steel with high surface zinc-repellent properties. The surface of the carbon steel with high surface zinc-repellent properties is black, and the density of the silicide coating on the carbon steel surface is 97%. The composition of the silicide coating is Fe2O3 and SiO2, and the size is 79μm.

[0111] The prepared high-temperature pre-oxidized siliconized carbon steel has a smooth and flat surface, and the silicide coating on the carbon steel surface undergoes selective oxidation to form a low surface energy SiO2 oxide film. The low surface energy SiO2 oxide film effectively prevents the adhesion and diffusion of Zn in the molten Zn liquid.

[0112] A method for testing the zinc-repellent properties of high-surface zinc-repellent carbon steel obtained based on the preparation method of this embodiment, wherein the zinc-repellent property testing method is as follows: Figure 2 The steps shown are as follows:

[0113] SS1, Zinc immersion test

[0114] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. Several zinc blocks were placed in a muffle furnace and heated to melt into molten zinc. Then, the aforementioned three different types of carbon steel were placed in the molten zinc and kept at a certain temperature. After the holding time was completed, the adhesion ability V of the molten zinc to the carbon steel was calculated according to the following formula. zn :

[0115]

[0116] Where: V zn >0, unit is mg / cm³ 2 •h; m1 is the mass of carbon steel before immersion, m2 is the mass of carbon steel after immersion, both in mg; s is the surface area of ​​carbon steel in cm². 2 t represents the soaking time, in hours (h).

[0117] SS2, High-temperature wetting angle test

[0118] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. A zinc block was placed at the center of each of the three different carbon steels, followed by vacuuming and image acquisition. The zinc block was then heated to melt it into molten zinc, and the mixture was kept at that temperature until the Zn metal no longer spread. The furnace was then cooled. The wetting angle θ of the molten zinc on the three different carbon steels was calculated using the following formula:

[0119]

[0120] Where: h is the height of the zinc liquid around the carbon steel, in mm; d is the contact length of the carbon steel, in mm;

[0121] SS3, High-Temperature Roll Angle Test

[0122] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. Then, they were placed on a high-temperature roll-off angle measuring instrument. Zinc liquid was then dripped onto the surface of the three different carbon steels using the instrument. The measuring instrument was slowly rotated until the zinc liquid just rolled off the surface of the three different carbon steels. The roll-off angle α of the three different carbon steels was then read and recorded. The roll-off angle of each group of three different carbon steels was measured more than three times, and the average value was taken as the final high-temperature roll-off angle of the three different carbon steels.

[0123] The final results show the adhesion V of the zinc bath to carbon steel obtained from the following processes: carbon steel without material pretreatment in step S1, silicon-infiltrated carbon steel in step S3, and high surface zinc-repellent carbon steel obtained in step S4. zn 45.96 mg / cm 2 ·h, 0.69mg / cm 2 ·h, 0.38mg / cm 2 The high-temperature wetting angles are 36°, 124°, and 135°, respectively, and the high-temperature rolling angles are 86°, 36°, and 32°, respectively.

[0124] Table 3

[0125]

[0126] Example 4

[0127] A method for preparing carbon steel with high surface zinc-repellent properties, the method being as follows: Figure 1 The steps shown are as follows:

[0128] S1, Material Pretreatment

[0129] The carbon steel is subjected to grinding, polishing, ultrasonic cleaning and drying in sequence. Grinding is performed by surface grinding with 120-1200# sandpaper, polishing is performed by surface polishing with 1.5-2.5μm diamond polishing paste, and ultrasonic cleaning is performed by surface cleaning with anhydrous ethanol added to an ultrasonic cleaner to obtain pretreated carbon steel material.

[0130] S2, Preparation of Silicate Infiltrating Agent

[0131] The silicon-supplying agent, filler, thermally conductive agent, and infiltration catalyst are weighed and prepared according to the silicon-infiltrating agent ratio, and then ground evenly to obtain the silicon-infiltrating agent product. The silicon-infiltrating agent consists of 45 wt.% silicon-supplying agent, 1 wt.% infiltration catalyst, 54 wt.% filler, and thermally conductive agent. The silicon-supplying agent, filler, and thermally conductive agent in the silicon-infiltrating agent are all 100-200 mesh. The silicon-supplying agent is ferrosilicon powder, the infiltration catalyst is at least one of sodium fluoride, ammonium fluoride, and ammonium chloride, the filler is 24 wt.% high-temperature α-alumina, and the thermally conductive agent is 50 wt.% diamond sand.

[0132] S3, Preparation of silicide coating

[0133] The pretreated carbon steel material from step S1 and the silicon infiltrating agent from step S2 are simultaneously placed in a crucible. 20mm of silicon infiltrating agent is placed at the top and bottom of the crucible, with a 15mm gap between the carbon steel pieces. The crucible is then sealed with high-temperature adhesive and water glass. After sealing, it is placed in a muffle furnace for heat treatment at a temperature of 1050℃, a holding time of 6 hours, and a heating rate of 3℃ / min. Finally, it is cooled to room temperature with the furnace to obtain silicon-infiltrated carbon steel material with a silicide coating. The surface of the silicon-infiltrated carbon steel material is grayish-white, and the density of the silicide coating on the carbon steel surface is 96%. The composition of the silicide coating is Fe3Si and FeSi, with a size of 71μm.

[0134] S4, High-temperature pre-oxidation treatment

[0135] The silicon-diffused carbon steel material in step S3 is ultrasonically cleaned and dried, and then pre-oxidized in high-temperature static air. The temperature of the high-temperature static air is 950°C, and the pre-oxidation time is 10 hours, to obtain carbon steel with high surface zinc-repellent properties. The surface of the carbon steel with high surface zinc-repellent properties is black, and the density of the silicide coating on the carbon steel surface is 99%. The composition of the silicide coating is Fe2O3 and SiO2, and the size is 91μm.

[0136] The prepared high-temperature pre-oxidized siliconized carbon steel has a smooth and flat surface, and the silicide coating on the carbon steel surface undergoes selective oxidation to form a low surface energy SiO2 oxide film. The low surface energy SiO2 oxide film effectively prevents the adhesion and diffusion of Zn in the molten Zn liquid.

[0137] A method for testing the zinc-repellent properties of high-surface zinc-repellent carbon steel obtained based on the preparation method of this embodiment, wherein the zinc-repellent property testing method is as follows: Figure 2 The steps shown are as follows:

[0138] SS1, Zinc immersion test

[0139] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. Several zinc blocks were placed in a muffle furnace and heated to melt into molten zinc. Then, the aforementioned three different types of carbon steel were placed in the molten zinc and kept at a certain temperature. After the holding time was completed, the adhesion ability V of the molten zinc to the carbon steel was calculated according to the following formula. zn :

[0140]

[0141] Where: V zn >0, unit is mg / cm³ 2 •h; m1 is the mass of carbon steel before immersion, m2 is the mass of carbon steel after immersion, both in mg; s is the surface area of ​​carbon steel in cm². 2 t represents the soaking time, in hours (h).

[0142] SS2, High-temperature wetting angle test

[0143] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. A zinc block was placed at the center of each of the three different carbon steels, followed by vacuuming and image acquisition. The zinc block was then heated to melt it into molten zinc, and the mixture was kept at that temperature until the Zn metal no longer spread. The furnace was then cooled. The wetting angle θ of the molten zinc on the three different carbon steels was calculated using the following formula:

[0144]

[0145] Where: h is the height of the zinc liquid around the carbon steel, in mm; d is the contact length of the carbon steel, in mm;

[0146] SS3, High-Temperature Roll Angle Test

[0147] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. Then, they were placed on a high-temperature roll-off angle measuring instrument. Zinc liquid was then dripped onto the surface of the three different carbon steels using the instrument. The measuring instrument was slowly rotated until the zinc liquid just rolled off the surface of the three different carbon steels. The roll-off angle α of the three different carbon steels was then read and recorded. The roll-off angle of each group of three different carbon steels was measured more than three times, and the average value was taken as the final high-temperature roll-off angle of the three different carbon steels.

[0148] The final results show the adhesion V of the zinc bath to carbon steel obtained from the following processes: carbon steel without material pretreatment in step S1, silicon-infiltrated carbon steel in step S3, and high surface zinc-repellent carbon steel obtained in step S4. zn 45.97 mg / cm 2 ·h, 0.53mg / cm 2 ·h, 0.29mg / cm 2 The high-temperature wetting angles are 36°, 133°, and 146°, respectively, and the high-temperature rolling angles are 86°, 32°, and 23°, respectively.

[0149] Table 4

[0150]

[0151] Example 5

[0152] A method for preparing carbon steel with high surface zinc-repellent properties, the method being as follows: Figure 1 The steps shown are as follows:

[0153] S1, Material Pretreatment

[0154] The carbon steel is subjected to grinding, polishing, ultrasonic cleaning and drying in sequence. Grinding is performed by surface grinding with 120-1200# sandpaper, polishing is performed by surface polishing with 1.5-2.5μm diamond polishing paste, and ultrasonic cleaning is performed by surface cleaning with anhydrous ethanol added to an ultrasonic cleaner to obtain pretreated carbon steel material.

[0155] S2, Preparation of Silicate Infiltrating Agent

[0156] The silicon feed agent, filler, thermal conductive agent, and infiltration catalyst are weighed and prepared according to the silicon infiltration agent ratio, and then ground evenly to obtain the silicon infiltration agent product. Among them, the silicon infiltration agent is composed of 42 wt.% silicon feed agent, 1 wt.% infiltration catalyst, 57 wt.% filler and thermal conductive agent. The silicon feed agent, filler and thermal conductive agent in the silicon infiltration agent are all 100-200 mesh. The silicon feed agent is a mixture of 70 wt.% ferrosilicon powder and 30 wt.% silicon powder. The infiltration catalyst is a mixture of 60 wt.% sodium fluoride and 40 wt.% ammonium fluoride. The filler is 50 wt.% high temperature α-alumina. The thermal conductive agent is 7 wt.% diamond sand.

[0157] S3, Preparation of silicide coating

[0158] The pretreated carbon steel material from step S1 and the silicon infiltrating agent from step S2 are simultaneously placed in a crucible. 18mm of silicon infiltrating agent is placed at the top and bottom of the crucible, with a 13mm gap between the carbon steel pieces. The crucible is then sealed with high-temperature adhesive and water glass. After sealing, it is placed in a muffle furnace for heat treatment at a temperature of 1000℃, a holding time of 7 hours, and a heating rate of 5℃ / min. Finally, it is cooled to room temperature with the furnace to obtain silicon-infiltrated carbon steel material with a silicide coating. The surface of the silicon-infiltrated carbon steel material is grayish-white, and the density of the silicide coating on the carbon steel surface is 95%. The composition of the silicide coating is Fe3Si and FeSi, with a size of 65μm.

[0159] S4, High-temperature pre-oxidation treatment

[0160] The silicon-diffused carbon steel material in step S3 is ultrasonically cleaned and dried, and then pre-oxidized in high-temperature static air. The temperature of the high-temperature static air is 970°C, and the pre-oxidation time is 8 hours, to obtain carbon steel with high surface zinc-repellent properties. The surface of the carbon steel with high surface zinc-repellent properties is black, and the density of the silicide coating on the carbon steel surface is 98%. The composition of the silicide coating is Fe2O3 and SiO2, and the size is 83μm.

[0161] The prepared high-temperature pre-oxidized siliconized carbon steel has a smooth and flat surface, and the silicide coating on the carbon steel surface undergoes selective oxidation to form a low surface energy SiO2 oxide film. The low surface energy SiO2 oxide film effectively prevents the adhesion and diffusion of Zn in the molten Zn liquid.

[0162] A method for testing the zinc-repellent properties of high-surface zinc-repellent carbon steel obtained based on the preparation method of this embodiment, wherein the zinc-repellent property testing method is as follows: Figure 2 The steps shown are as follows:

[0163] SS1, Zinc immersion test

[0164] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. Several zinc blocks were placed in a muffle furnace and heated to melt into molten zinc. Then, the aforementioned three different types of carbon steel were placed in the molten zinc and kept at a certain temperature. After the holding time was completed, the adhesion ability V of the molten zinc to the carbon steel was calculated according to the following formula. zn :

[0165]

[0166] Where: V zn >0, unit is mg / cm³ 2 •h; m1 is the mass of carbon steel before immersion, m2 is the mass of carbon steel after immersion, both in mg; s is the surface area of ​​carbon steel in cm². 2 t represents the soaking time, in hours (h).

[0167] SS2, High-temperature wetting angle test

[0168] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. A zinc block was placed at the center of each of the three different carbon steels, followed by vacuuming and image acquisition. The zinc block was then heated to melt it into molten zinc, and the mixture was kept at that temperature until the Zn metal no longer spread. The furnace was then cooled. The wetting angle θ of the molten zinc on the three different carbon steels was calculated using the following formula:

[0169]

[0170] Where: h is the height of the zinc liquid around the carbon steel, in mm; d is the contact length of the carbon steel, in mm;

[0171] SS3, High-Temperature Roll Angle Test

[0172] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. Then, they were placed on a high-temperature roll-off angle measuring instrument. Zinc liquid was then dripped onto the surface of the three different carbon steels using the instrument. The measuring instrument was slowly rotated until the zinc liquid just rolled off the surface of the three different carbon steels. The roll-off angle α of the three different carbon steels was then read and recorded. The roll-off angle of each group of three different carbon steels was measured more than three times, and the average value was taken as the final high-temperature roll-off angle of the three different carbon steels.

[0173] The final results show the adhesion V of the zinc bath to carbon steel obtained from the following processes: carbon steel without material pretreatment in step S1, silicon-infiltrated carbon steel in step S3, and high surface zinc-repellent carbon steel obtained in step S4. zn 45.96 mg / cm2 ·h, 0.69mg / cm 2 ·h, 0.35mg / cm 2 The high-temperature wetting angles are 36°, 128°, and 140°, respectively, and the high-temperature rolling angles are 86°, 34°, and 29°, respectively.

[0174] Table 5

[0175]

[0176] Example 6

[0177] A method for preparing carbon steel with high surface zinc-repellent properties, the method being as follows: Figure 1 The steps shown are as follows:

[0178] S1, Material Pretreatment

[0179] The carbon steel is subjected to grinding, polishing, ultrasonic cleaning and drying in sequence. Grinding is performed by surface grinding with 120-1200# sandpaper, polishing is performed by surface polishing with 1.5-2.5μm diamond polishing paste, and ultrasonic cleaning is performed by surface cleaning with anhydrous ethanol added to an ultrasonic cleaner to obtain pretreated carbon steel material.

[0180] S2, Preparation of Silicate Infiltrating Agent

[0181] The silicon-supplying agent, filler, thermally conductive agent, and infiltration catalyst are weighed and prepared according to the silicon-diffusion agent ratio, and then ground evenly to obtain the silicon-diffusion agent product. The silicon-diffusion agent consists of 38 wt.% silicon-supplying agent, 1 wt.% infiltration catalyst, 61 wt.% filler, and thermally conductive agent. The silicon-supplying agent, filler, and thermally conductive agent are all 100-200 mesh. The silicon-supplying agent is silicon powder, the infiltration catalyst is ammonium chloride, the filler is 52 wt.% high-temperature α-alumina, and the thermally conductive agent is 9 wt.% diamond sand.

[0182] S3, Preparation of silicide coating

[0183] The pretreated carbon steel material from step S1 and the silicon infiltrating agent from step S2 are simultaneously placed in a crucible. 16mm of silicon infiltrating agent is placed at the top and bottom of the crucible, with a 14mm gap between the carbon steel pieces. The crucible is then sealed with high-temperature adhesive and water glass. After sealing, it is placed in a muffle furnace for heat treatment at 970℃ for 8 hours at a heating rate of 6℃ / min. Finally, it is cooled to room temperature with the furnace to obtain silicon-infiltrated carbon steel material with a silicide coating. The surface of the silicon-infiltrated carbon steel material is grayish-white, and the density of the silicide coating on the carbon steel surface is 93%. The silicide coating consists of Fe3Si and FeSi, with a size of 57μm.

[0184] S4, High-temperature pre-oxidation treatment

[0185] The silicon-diffused carbon steel material in step S3 is ultrasonically cleaned and dried, and then pre-oxidized in high-temperature static air. The temperature of the high-temperature static air is 1000℃, and the pre-oxidation time is 6h, to obtain carbon steel with high surface zinc-repellent properties. The surface of the carbon steel with high surface zinc-repellent properties is black, and the density of the silicide coating on the carbon steel surface is 96%. The composition of the silicide coating is Fe2O3 and SiO2, and the size is 75μm.

[0186] The prepared high-temperature pre-oxidized siliconized carbon steel has a smooth and flat surface, and the silicide coating on the carbon steel surface undergoes selective oxidation to form a low surface energy SiO2 oxide film. The low surface energy SiO2 oxide film effectively prevents the adhesion and diffusion of Zn in the molten Zn liquid.

[0187] A method for testing the zinc-repellent properties of high-surface zinc-repellent carbon steel obtained based on the preparation method of this embodiment, wherein the zinc-repellent property testing method is as follows: Figure 2 The steps shown are as follows:

[0188] SS1, Zinc immersion test

[0189] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. Several zinc blocks were placed in a muffle furnace and heated to melt into molten zinc. Then, the aforementioned three different types of carbon steel were placed in the molten zinc and kept at a certain temperature. After the holding time was completed, the adhesion ability V of the molten zinc to the carbon steel was calculated according to the following formula. zn :

[0190]

[0191] Where: V zn >0, unit is mg / cm³ 2 •h; m1 is the mass of carbon steel before immersion, m2 is the mass of carbon steel after immersion, both in mg; s is the surface area of ​​carbon steel in cm². 2 t represents the soaking time, in hours (h).

[0192] SS2, High-temperature wetting angle test

[0193] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. A zinc block was placed at the center of each of the three different carbon steels, followed by vacuuming and image acquisition. The zinc block was then heated to melt it into molten zinc, and the mixture was kept at that temperature until the Zn metal no longer spread. The furnace was then cooled. The wetting angle θ of the molten zinc on the three different carbon steels was calculated using the following formula:

[0194]

[0195] Where: h is the height of the zinc liquid around the carbon steel, in mm; d is the contact length of the carbon steel, in mm;

[0196] SS3, High-Temperature Roll Angle Test

[0197] The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. Then, they were placed on a high-temperature roll-off angle measuring instrument. Zinc liquid was then dripped onto the surface of the three different carbon steels using the instrument. The measuring instrument was slowly rotated until the zinc liquid just rolled off the surface of the three different carbon steels. The roll-off angle α of the three different carbon steels was then read and recorded. The roll-off angle of each group of three different carbon steels was measured more than three times, and the average value was taken as the final high-temperature roll-off angle of the three different carbon steels.

[0198] The final results show the adhesion V of the zinc bath to carbon steel obtained from the following processes: carbon steel without material pretreatment in step S1, silicon-infiltrated carbon steel in step S3, and high surface zinc-repellent carbon steel obtained in step S4. zn 45.96 mg / cm 2 ·h, 0.73mg / cm 2 ·h, 0.44mg / cm 2 The high-temperature wetting angles are 36°, 120°, and 131°, respectively, and the high-temperature rolling angles are 86°, 38°, and 35°, respectively.

[0199] Table 6

[0200]

[0201] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0202] This invention employs an embedded silicon-infiltrating chemical surface heat treatment technique to prepare a silicide coating on the surface of carbon steel. The surface of the silicon-infiltrating carbon steel material is grayish-white, and the density of the silicide coating on the carbon steel surface is 91-96%. The composition of the silicide coating is Fe3Si and FeSi, and the size is 40-71μm.

[0203] This invention uses a high-temperature pre-oxidation test to treat silicon-diffused carbon steel. The surface of the carbon steel with high surface zinc-repellent properties is black, and the density of the silicide coating on the carbon steel surface is 94-99%. The composition of the silicide coating is Fe2O3 and SiO2, and the size is 55-91μm.

[0204] This invention employs zinc immersion tests, high-temperature wetting angle tests, and high-temperature rolling angle tests to comprehensively test the zinc-repellent properties of material surfaces. The methods are simple and convenient, and the adhesion ability of zinc immersion to carbon steel on different material surfaces is measured (V). zn The comparison of wetting angle and roll-off angle can accurately and intuitively test the comprehensive zinc-repellent properties of different surfaces.

[0205] The zinc immersion test, high-temperature wetting angle test, and high-temperature rolling angle test of this invention provide a comprehensive test of the zinc-repellent properties of the material surface with an accuracy rate of 98%. The adhesion of the low surface energy functional layer after pre-oxidation treatment is 0.29-0.63 mg / cm². 2 ·h.

[0206] In summary, the present invention provides a method for preparing carbon steel with high surface zinc-repellent properties and a method for testing zinc-repellent properties. The process is simple and low-cost. The prepared silicon-infiltrated coating is uniform and dense. After pre-oxidation treatment, the low surface energy functional layer has low adhesion. Through the three assessment methods designed in this invention, the zinc-repellent properties of different carbon steel surfaces can be accurately and intuitively tested. It has a wide range of applications and is suitable for large-scale industrial production and widespread use.

[0207] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing carbon steel with high surface zinc-repellent properties, characterized in that, The preparation method includes the following steps: S1, Material Pretreatment The carbon steel is sequentially ground, polished, ultrasonically cleaned, and dried to obtain the pretreated carbon steel material. S2, Preparation of Silicate Infiltrating Agent The silicon-supplying agent, filler, thermal conductive agent, and infiltration catalyst are weighed and prepared according to the silicon-infiltrating agent ratio. The silicon-supplying agent is at least one of ferrosilicon powder and silicon powder, the infiltration catalyst is at least one of sodium fluoride, ammonium fluoride, and ammonium chloride, the filler is high-temperature α-alumina, and the thermal conductive agent is diamond sand. After grinding, the silicon-infiltrating agent product is obtained. S3, Preparation of silicide coating The pretreated carbon steel material from step S1 and the silicon infiltrating agent from step S2 are placed in a crucible at the same time, and the silicon infiltrating agent is uniformly covered on the surface of the pretreated carbon steel material; then the crucible is placed in a muffle furnace for heat treatment to obtain silicon-infiltrated carbon steel material with a silicide coating on the surface. S4, High-temperature pre-oxidation treatment The silicon-dipped carbon steel material in step S3 is ultrasonically cleaned and dried, and then pre-oxidized in high-temperature static air to obtain carbon steel with high surface zinc-repellent properties.

2. The method for preparing high surface zinc-repellent carbon steel as described in claim 1, characterized in that, In step S1, grinding is performed by surface grinding with 120-1200# sandpaper, polishing is performed by surface polishing with 1.5-2.5μm diamond polishing paste, and ultrasonic cleaning is performed by surface cleaning with anhydrous ethanol added to an ultrasonic cleaner.

3. The method for preparing high surface zinc-repellent carbon steel as described in claim 1, characterized in that, In step S2, the silicon infiltration agent consists of 30-45 wt.% silicon supply agent, 1 wt.% infiltration catalyst, 54-69 wt.% filler and thermal conductive agent.

4. The method for preparing high surface zinc-repellent carbon steel as described in claim 3, characterized in that, In step S2, the silicating agent, filler, and thermal conductive agent in the silicating agent are all 100-200 mesh.

5. The method for preparing high surface zinc-repellent carbon steel as described in claim 1, characterized in that, In step S3, the heat treatment is as follows: heating temperature 950-1050℃, holding time 5-10h, heating rate 3-8℃ / min, and finally cooling to room temperature with the furnace.

6. The method for preparing high surface zinc-repellent carbon steel as described in claim 1, characterized in that, In step S4, the temperature of the high-temperature static air is 950-1000℃, and the pre-oxidation treatment time is 5-10h.

7. The method for preparing high surface zinc-repellent carbon steel as described in claim 1, characterized in that, In step S3, the surface of the silicon-diffused carbon steel material is grayish-white, and the density of the silicide coating on the carbon steel surface is 91-96%. The composition of the silicide coating is Fe3Si and FeSi, and the size is 40-71μm. In step S4, the surface of the carbon steel with high surface zinc-repellent properties is black, and the density of the silicide coating on the carbon steel surface is 94-99%. The composition of the silicide coating is Fe2O3 and SiO2, and the size is 55-91μm.

8. A method for testing the zinc-repellent properties of high-surface zinc-repellent carbon steel obtained by the preparation method according to any one of claims 1-7, characterized in that, The zinc-repellent performance test method includes the following steps: SS1, Zinc immersion test The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. Several zinc blocks were placed in a muffle furnace and heated to melt into molten zinc. Then, the aforementioned three different types of carbon steel were placed in the molten zinc and kept at a certain temperature. After the holding time was completed, the adhesion ability V of the molten zinc to the carbon steel was calculated according to the following formula. zn : Where: V zn >0, unit is mg / cm³ 2 •h; m1 is the mass of carbon steel before immersion, m2 is the mass of carbon steel after immersion, both in mg; s is the surface area of ​​carbon steel in cm². 2 t represents the soaking time, in hours (h). SS2, High-temperature wetting angle test The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. A zinc block was placed at the center of each of the three different carbon steels, followed by vacuuming and image acquisition. The zinc block was then heated to melt it into molten zinc, and the mixture was kept at that temperature until the Zn metal no longer spread. The furnace was then cooled. The wetting angle θ of the molten zinc on the three different carbon steels was calculated using the following formula: Where: h is the height of the zinc liquid around the carbon steel, in mm; d is the contact length of the carbon steel, in mm; SS3, High-Temperature Roll Angle Test The carbon steel without material pretreatment in step S1, the silicon-infiltrated carbon steel in step S3, and the high surface zinc-repellent carbon steel obtained in step S4 were ultrasonically cleaned and dried. Then, they were placed on a high-temperature roll-off angle measuring instrument. Zinc liquid was then dripped onto the surface of the three different carbon steels using the instrument. The measuring instrument was slowly rotated until the zinc liquid just rolled off the surface of the three different carbon steels. The roll-off angle α of the three different carbon steels was then read and recorded. The roll-off angle of each group of three different carbon steels was measured more than three times, and the average value was taken as the final high-temperature roll-off angle of the three different carbon steels.

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