Preparation method and preparation apparatus for corrosion-resistant hot stamping part, and method for improving adhesive performance of evaporated part

Abstract

A preparation method for a corrosion-resistant hot stamping part, comprising the following steps: blanking a bare plate into a billet having a preset shape; feeding the billet into a heating furnace for heating, so that the billet is austenitized; putting the austenitized billet to a die for stamping, so that the austenitized billet is formed into a part; performing surface pretreatment on the formed part, so as to obtain a part to be plated; and performing evaporation on said obtained part for less than 30 min, to form a galvanized layer or a zinc alloy layer having a thickness greater than 3 um on the surface of said part. A preparation apparatus for a corrosion-resistant hot stamping part, comprising a blanking mechanism, a heating mechanism, a forming mechanism, a vapor deposition pretreatment mechanism, and an evaporating mechanism. A method for improving an adhesive performance of an evaporated part, comprising the following steps: feeding a part to an evaporating mechanism and vacuumizing the evaporating mechanism; performing plasma cleaning on the part fed into the evaporating mechanism; and performing vacuum evaporation deposition and heating on the plasma-cleaned part, so as to form a dense coating on the surface of the part; or, first performing vacuum evaporation deposition on the plasma-cleaned part and then heating same, so as to form a dense coating on the surface of the part. An evaporating process is used instead of electroplating, and a galvanized layer or a zinc alloy layer is quickly applied to the surface of a part to be plated, so that no hydrogen embrittlement risks occur during the formation of the galvanized layer or the zinc alloy layer, a tempering dehydrogenation treatment is not needed, and the prepared hot stamping part also has an excellent corrosion resistance. The plasma-cleaned part is subjected to vacuum evaporation deposition and heating at the same time, or the plasma-cleaned part is subjected to vacuum evaporation deposition and then heated, so that atoms for forming the coating can be diffused, and a gas in voids of the coating is discharged after being heated, and thus a rough coating on the surface of the part can become a dense coating, and subsequent bonding with a structural adhesive is facilitated.

Description

Preparation method and device of corrosion-resistant hot stamping parts, and method for improving the adhesive properties of vapor-deposited parts

[0001] Cross-reference related references

[0002] This application claims priority to Chinese patent applications No. 2023111417258, filed on September 6, 2023, entitled “A method and device for preparing corrosion-resistant hot stamping parts” and No. 2024110625991, filed on August 5, 2024, entitled “A method for improving the adhesive properties of vapor-deposited parts”, and the above applications are incorporated herein by reference. Technical Field

[0003] The present invention belongs to the field of hot stamping forming technology, and in particular relates to a method and apparatus for preparing corrosion-resistant hot stamping parts. The present invention belongs to the field of hot stamping surface treatment technology, and in particular relates to a method for improving the adhesive properties of vapor-deposited parts. Background Art

[0004] At present, the hot stamping industry generally adopts several processes, including bare plate hot stamping, aluminum silicon coating hot stamping, galvanized plate hot stamping and bare plate hot stamping followed by electrogalvanizing. Among them, a large amount of oxide scale is generated in the bare plate hot stamping process, and the formed parts have no corrosion resistance. Although aluminum silicon / galvanized hot stamping parts have good antioxidant ability, their corrosion resistance is poor. Patent CN109821951A discloses a method and device for preparing corrosion-resistant hot stamping parts, which proposes a method of electrogalvanizing after hot forming parts to effectively increase the corrosion resistance of hot stamping parts. However, there is a risk of hydrogen embrittlement during the electroplating process, and tempering treatment is required to remove hydrogen. In addition, wastewater and waste gas are generated during the electroplating process, which is prone to environmental problems, and additional wastewater treatment equipment and waste gas treatment equipment are required.

[0005] Summary of the Invention

[0006] The inventors have creatively discovered that by using an evaporation process instead of electroplating, a zinc coating or zinc alloy layer is quickly applied to the surface of the parts to be plated, so that there is no risk of hydrogen embrittlement during the formation of the zinc coating or zinc alloy layer, and no tempering and dehydrogenation treatment is required. At the same time, the hot stamped parts prepared also have excellent corrosion resistance. In addition, no waste water and waste gas are generated during the coating application process, thus avoiding pollution to the environment. However, hot stamped automotive parts often need to be coated with structural adhesive so that they can be bonded together with other parts to improve the bonding strength, instead of being treated without subsequent gluing like general vacuum-coated parts (such as mobile phone cases and optical lenses). However, experimental studies have shown that if the vacuum evaporation process is directly used to apply the coating to the hot stamped parts and then apply the glue, the adhesive performance does not meet the qualified requirements, that is, the coating formed by vacuum evaporation cannot be bonded to the structural adhesive.

[0007] In view of the problems existing in the above-mentioned prior art, a main purpose of the present invention is to provide a method and apparatus for preparing corrosion-resistant hot stamping parts, in which a zinc coating or zinc alloy layer is quickly applied to the parts after hot stamping and surface pretreatment by a vapor deposition process. There is no risk of hydrogen embrittlement during the coating formation process, and no tempering dehydrogenation treatment is required. The hot stamping parts prepared have excellent corrosion resistance.

[0008] In view of the problems existing in the above-mentioned prior art, another main purpose of the present invention is to provide a method for improving the adhesive properties of vapor-deposited parts. The provided method for improving the adhesive properties of vapor-deposited parts can effectively improve the adhesive properties of the surface of the vapor-deposited parts.

[0009] The present invention provides a method for preparing a corrosion-resistant hot stamping part, comprising the following steps:

[0010] Blanking the bare board into blanks of preset shapes;

[0011] The blank is fed into a heating furnace for heating to austenitize the blank;

[0012] placing the austenitized blank into a die for stamping to form it into a part;

[0013] Performing surface pretreatment on the formed parts to obtain parts to be plated;

[0014] The obtained parts to be plated are subjected to evaporation for less than 30 minutes to form a zinc plating layer or zinc alloy layer with a thickness greater than 3 μm on the surface.

[0015] As a further description of the above technical solution, the thickness of the galvanized layer is 5um-13um.

[0016] As a further description of the above technical solution, in the step of "evaporating the obtained parts to be plated for less than 30 minutes to form a zinc plating layer or zinc alloy layer with a thickness greater than 3um on the surface", the time for evaporating the parts to be plated is 3 minutes to 10 minutes.

[0017] As a further description of the above technical solution, the step of "performing evaporation deposition on the obtained part to be plated for less than 30 minutes to form a zinc coating or zinc alloy coating having a thickness greater than 3 μm on the surface thereof" includes:

[0018] Sending the obtained parts to be plated into a vapor deposition mechanism;

[0019] Vacuuming the evaporation mechanism;

[0020] Performing evaporation on the parts to be plated that are fed into the evaporation mechanism to obtain parts with a zinc coating or zinc alloy coating formed on their surfaces;

[0021] The evaporation mechanism is subjected to vacuum breaking to form a part with a zinc coating or zinc alloy coating on its surface.

[0022] As a further description of the above technical solution, in the step of "evaporating the parts to be plated sent into the evaporation mechanism to obtain parts with a zinc coating layer or a zinc alloy layer formed on the surface", the parts to be plated are in a rotating state.

[0023] As a further description of the above technical solution, in the step of "evaporating the parts to be plated into the evaporation mechanism to obtain parts with a zinc coating or zinc alloy layer formed on the surface", the temperature of the parts to be plated is less than 200°C.

[0024] As a further description of the above technical solution, the temperature of the part to be plated is less than 50°C.

[0025] As a further description of the above technical solution, in the step of "blanking the bare plate into a blank of a preset shape", the bare plate is a hot-formed bare steel plate with a strength of not less than 1500 MPa.

[0026] As a further description of the above technical solution, the strength of the hot-formed bare steel plate is 1500 MPa or 2000 MPa.

[0027] As a further description of the above technical solution, in the step of "sending the blank into a heating furnace for heating to austenitize the blank", the heating furnace includes a vacuum heating furnace or an atmosphere heating furnace, and the oxygen content in the heating furnace is less than 0.01%.

[0028] As a further description of the above technical solution, the vacuum degree in the vacuum heating furnace is less than 100Pa.

[0029] As a further description of the above technical solution, the vacuum degree in the vacuum heating furnace is 1Pa-10Pa.

[0030] As a further description of the above technical solution, in the step of "subjecting surface pretreatment to the formed part to obtain the part to be plated", the surface pretreatment includes sandblasting or pickling the formed part.

[0031] As a further description of the above technical solution, before the formed parts are sandblasted or pickled, the parts are also laser trimmed or cut.

[0032] The present invention also provides a device for preparing corrosion-resistant hot stamping parts, which adopts the above-mentioned preparation method and includes a blanking mechanism, a heating mechanism, a forming mechanism, a vapor deposition pre-treatment mechanism and a vapor deposition mechanism, wherein:

[0033] The blanking mechanism is used to blank the bare steel plate into a blank of a preset shape;

[0034] The heating mechanism is used to heat the blank formed into a preset shape;

[0035] The forming mechanism is used to form the heated blank into a part;

[0036] The evaporation pre-treatment mechanism is used to perform surface pre-treatment on the formed parts to obtain parts to be plated;

[0037] The evaporation mechanism is used to perform evaporation on the obtained parts to be plated for less than 30 minutes, so that a zinc coating layer or a zinc alloy layer with a thickness greater than 3 μm is formed on the surface.

[0038] In summary, the outstanding effects of the present invention are:

[0039] The method for preparing corrosion-resistant hot stamping parts provided by the present invention adopts an evaporation process instead of electroplating during the forming process of hot-formed stamping parts, and quickly applies a zinc coating layer or a zinc alloy layer on the surface of the part to be plated. There is no risk of hydrogen embrittlement during the formation of the zinc coating layer or the zinc alloy layer, and no tempering dehydrogenation treatment is required. The prepared hot stamping parts also have excellent corrosion resistance. In addition, the zinc coating layer or the zinc alloy layer is applied to the surface of the part to be plated by evaporation, which does not generate wastewater and waste gas, thereby avoiding pollution to the environment.

[0040] The present invention provides a method for improving the adhesive properties of a vapor-deposited part, comprising the following steps:

[0041] Send the parts into the evaporation mechanism and evacuate the evaporation mechanism;

[0042] Plasma cleaning is performed on the parts fed into the evaporation mechanism;

[0043] performing vacuum evaporation and heating on the plasma-cleaned part to form a dense coating on the surface of the part; or,

[0044] The plasma-cleaned part is vacuum-deposited and then heated to form a dense coating on the surface of the part.

[0045] As a further description of the above technical solution, in the step of "vacuum evaporating and heating the part after plasma cleaning to form a dense coating on the surface of the part; or vacuum evaporating and then heating the part after plasma cleaning to form a dense coating on the surface of the part", the material used to form the dense coating is pure zinc or zinc alloy.

[0046] As a further description of the above technical solution, in the step of "vacuum evaporating and heating the part after plasma cleaning to form a dense coating on the surface of the part; or vacuum evaporating and then heating the part after plasma cleaning to form a dense coating on the surface of the part", the heating temperature is not greater than 200°C and the heating time is less than 4 hours.

[0047] As a further description of the above technical solution, after the step of "vacuum evaporating and heating the part after plasma cleaning to form a dense coating on the surface of the part; or vacuum evaporating and then heating the part after plasma cleaning to form a dense coating on the surface of the part", the surface oxide of the part is also removed.

[0048] As a further description of the above technical solution, plasma cleaning is used to remove surface oxides from the parts.

[0049] As a further description of the above technical solution, a plasma cleaning method is used in the evaporation mechanism or outside the evaporation mechanism to remove surface oxides of the parts.

[0050] As a further description of the above technical solution, chemical cleaning is used to remove surface oxides of the parts.

[0051] As a further description of the above technical solution, HNO3 solution or other chemical agents with a weight percentage concentration of 0.1%-5% are used to remove surface oxides of the parts.

[0052] As a further description of the above technical solution, after the step of "performing vacuum evaporation on the parts after plasma cleaning", the evaporation mechanism is also vacuumed for a preset time.

[0053] As a further description of the above technical solution, before the step of "sending the parts into the evaporation mechanism and evacuating the evaporation mechanism", the parts are also subjected to surface pretreatment.

[0054] By means of the above technical solutions, the outstanding effects of the present invention are:

[0055] 1. In the method for improving the adhesive properties of vapor-deposited parts provided by the present invention, the parts are heated while being vacuum-deposited after plasma cleaning, or after being vacuum-deposited, so that the atoms forming the coating can diffuse and the gas in the pores of the coating is discharged by heat. As a result, the coarse coating on the surface of the part is converted into a dense coating, which is conducive to subsequent bonding with structural adhesive.

[0056] 2. After a dense coating is formed on the surface of the part, the surface is cleaned by plasma cleaning or pickling to remove oxides and other impurities, while increasing its surface activation energy, thereby improving the adhesive properties of the part surface (coating). BRIEF DESCRIPTION OF THE DRAWINGS

[0057] FIG1 is a flow chart of a method for preparing a corrosion-resistant hot stamping part according to an embodiment of the present invention;

[0058] FIG2 is a schematic diagram of a first structure of the evaporation mechanism according to an embodiment of the present invention;

[0059] FIG3 is a schematic diagram of a second structure of the evaporation mechanism according to an embodiment of the present invention;

[0060] FIG4 is a diagram showing the hot stamping anti-collision beam after the zinc coating is applied by evaporation in Example 1 of the present invention;

[0061] FIG5 is a graph showing the test results of the bonding strength of the galvanized layer after the galvanized layer is applied by evaporation to the anti-collision beam formed by hot stamping in Example 1 of the present invention;

[0062] FIG6 is a corrosion diagram of the anti-collision beam formed by hot stamping in Example 1 of the present invention after a 48-hour neutral salt spray test with a galvanized layer after evaporation;

[0063] FIG7 is a diagram showing the state of the hot stamping reinforcement plate after the zinc-aluminum alloy layer is evaporated and applied in Example 2 of the present invention;

[0064] FIG8 is a corrosion diagram of the hot stamping reinforcement plate in Example 2 of the present invention after a zinc-aluminum alloy layer is evaporated and applied, and then subjected to a 68-hour neutral salt spray test.

[0065] FIG9 is a schematic diagram showing the adhesive performance test results of the vapor-deposited part obtained by the vapor deposition method;

[0066] FIG10 is a schematic diagram showing the adhesive performance test results of a door sill component that has undergone evaporation and heating but has not undergone further surface oxide removal in accordance with an embodiment of the present invention;

[0067] FIG11 is a schematic diagram showing the result of applying structural adhesive and polishing a door sill component after evaporation and heating but without further surface oxide removal in accordance with an embodiment of the present invention;

[0068] FIG. 12 is a schematic diagram showing the adhesive performance test results of a door sill component after evaporation and heating and then removal of surface oxides according to an embodiment of the present invention. DETAILED DESCRIPTION

[0069] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0070] Referring to FIG1 , an embodiment of the present invention provides a method for preparing a corrosion-resistant hot stamping part, comprising the following steps:

[0071] First, a bare plate of a preset model is blanked into a blank of a preset shape. The specific blanking methods include cold stamping and laser cutting. The bare plate in this embodiment is a hot-formed bare steel plate with a strength of not less than 1500 MPa (a bare steel plate is generally understood as a steel plate without a coating on the surface), and its strength is preferably 1500 MPa or 2000 MPa.

[0072] Next, the blank is sent into a heating furnace for heating to austenitize the blank. Specifically, the blanked blank is sent into the heating furnace for heating to reach an austenitic state and heat preservation, so that the austenite in the blank is homogenized. The heating furnace is an oxygen-free heating furnace, including a vacuum heating furnace or an atmosphere heating furnace, wherein the vacuum degree of the vacuum heating furnace is less than 100Pa, and preferably, the vacuum degree of the vacuum heating furnace is 1-10Pa. Specifically, after the chamber door of the vacuum heating furnace is closed, the vacuum pumping device is started to vacuum the furnace. After the vacuum pumping reaches a preset time, the vacuum degree in the furnace reaches 1-10Pa, and then, for example, a preset high-purity nitrogen gas is used to inflate the vacuum heating furnace to reach one atmospheric pressure. Then, the heating device in the furnace can be started to heat and keep the blank warm to austenitize it. It should be understood that the time for heating and keeping the blank warm can be adjusted according to the thickness of the different blanks. The oxygen content in the heating furnace is less than 0.01%, allowing the blank to be heated to a high temperature in an oxygen-free environment, significantly reducing oxidation. This ensures the surface quality of the formed parts and effectively shortens the subsequent sandblasting process. After heating, there is virtually no residual oxide on the surface of the parts, significantly reducing the pickling time before surface coating.

[0073] Next, an end effector is used to quickly place the austenitized blank into a die for stamping, forming it into a part. Specifically, the blank is transferred from the heating furnace to the die in approximately 5-10 seconds, effectively reducing the time the hot blank is exposed to air, preventing oxidation and a significant drop in temperature. Hot stamping also contributes to the excellent mechanical properties of the resulting part.

[0074] The formed part then undergoes surface pretreatment to obtain a part to be plated. Specifically, the surface pretreatment includes sandblasting or pickling the formed part to remove surface oxide scale. Sandblasting the formed part not only effectively removes surface oxide scale but also increases the surface roughness of the part, thereby improving the bonding strength of the part. Specifically, in this embodiment, before sandblasting or pickling the formed part, the part undergoes necessary laser trimming or hole cutting.

[0075] Finally, the obtained part to be plated is subjected to evaporation deposition for less than 30 minutes using an evaporation mechanism, forming a zinc coating or zinc alloy layer with a thickness greater than 3 μm on the surface. Preferably, the zinc coating has a thickness of 5 μm to 13 μm. Within this thickness range, the zinc coating not only has good corrosion resistance but also good weldability. Preferably, the evaporation deposition time on the part to be plated is 3 to 10 minutes, which can complete the application of the desired zinc coating thickness. This process includes: feeding the obtained part to be plated into an evaporation mechanism; then evaporating the evaporation mechanism; then evaporating the part to be plated into the evaporation mechanism to obtain a part with a zinc coating or zinc alloy layer on its surface. During the evaporation deposition process, the part to be plated is in a rotating state, that is, during the evaporation process, the part to be plated rotates within the evaporation chamber. This rotation ensures that the zinc coating or zinc alloy layer is applied uniformly to the surface of the part to be plated; and finally, breaking the vacuum in the evaporation mechanism to remove the obtained part with a zinc coating or zinc alloy layer on its surface. Specifically, in this embodiment, the evaporation mechanism can include a continuous vacuum evaporation production line as shown in Figure 2, wherein the parts to be plated are loaded one by one in their loading area, and then transferred to the feed buffer chamber for vacuuming before evaporation. After reaching the required vacuum degree, the partition door connected to the feed buffer chamber is opened to allow it to enter the vacuum evaporation chamber for the application of the zinc coating or zinc alloy layer. After the evaporation is completed, the partition door of the discharge buffer chamber connected to the downstream is opened to allow it to enter the discharge buffer chamber. The discharge buffer chamber has been vacuumed before the partition door is opened. After the buffering time is preset, the vacuum is broken and the discharge door of the discharge buffer chamber is opened to allow the parts with the zinc coating or zinc alloy layer applied to be transported to the unloading area for unloading. In addition, the evaporation mechanism can include a periodic vacuum evaporation production line as shown in Figure 3, wherein the parts to be plated can be hung on the hanger of the vacuum evaporation furnace, and then rapid vacuuming is performed to make the vacuum value of the vacuum evaporation furnace reach the preset value, and then the parts to be plated are evaporated to form a zinc coating or zinc alloy layer thereon. After the galvanized layer or zinc alloy layer is applied, the vacuum is broken and the material is removed.

[0076] Specifically, in this embodiment, in the step of "evaporating the part to be plated into the evaporation mechanism to obtain a part having a zinc or zinc alloy layer formed on its surface," the temperature of the part to be plated is less than 200°C, so that the performance of the part to be plated does not change significantly. Preferably, the temperature of the part to be plated is less than 50°C.

[0077] Specifically, in this embodiment, in the step of "evaporating the parts to be plated that are fed into the evaporation mechanism to obtain parts with a zinc coating or zinc alloy layer formed on the surface", the vacuum value in the vacuum evaporation chamber or vacuum evaporation furnace is maintained at about 10-2Pa. The setting of a low vacuum value is more conducive to the overflow of hydrogen generated during the aforementioned pickling process of the formed parts. The evaporation method is used to apply a zinc coating or zinc alloy layer to the surface of the parts to be plated, without the risk of hydrogen embrittlement and without the need for tempering to remove hydrogen. In addition, the evaporation method is used to apply a zinc coating or zinc alloy layer to the surface of the parts to be plated, which does not generate wastewater and waste gas, thereby avoiding pollution to the environment.

[0078] The present embodiment is described in detail below through specific embodiments:

[0079] Example 1:

[0080] First, the 1.6mm anti-collision beam blank is placed in a vacuum heating furnace for heating at a temperature of 930℃-950℃, a heating time of 5 minutes, and a vacuum degree of 10Pa to austenitize it.

[0081] Then, the heated austenitized anti-collision beam blank is stamped to form an anti-collision beam part;

[0082] Then the anti-collision beam parts after stamping are trimmed and holes are cut;

[0083] The finished anti-collision beam parts are then sandblasted to remove the oxide scale, thus obtaining the anti-collision beam parts to be plated. The sandblasting pressure is set at 0.3Mpa, and 220 mesh alumina sand is used;

[0084] Then, the obtained anti-collision beam parts to be plated are placed in the continuous vacuum evaporation production line as shown in Figure 2 for vacuum evaporation galvanizing. First, the anti-collision beam parts to be plated are placed on the hanger of the vacuum evaporation furnace and enter the feed buffer chamber. After the feed buffer chamber reaches the required vacuum degree, open the partition door connected to the vacuum evaporation chamber on the right side to allow it to enter the vacuum evaporation chamber. During the evaporation galvanizing process, the anti-collision beam parts rotate and move forward. During the evaporation process, the temperature inside the vacuum evaporation furnace is consistent with the room temperature. After 5 minutes of evaporation, open the partition door connecting the vacuum evaporation chamber and the discharge buffer chamber on its right side to allow the anti-collision beam parts to enter the discharge buffer chamber. After the evaporation is completed, break the vacuum, open the discharge door of the discharge buffer chamber, and take out the evaporated parts. The thickness of the zinc coating on the surface of the anti-collision beam parts after evaporation is 5um-7um.

[0085] Example 2:

[0086] First, the 1.4 mm reinforced plate blank obtained by blanking is placed in a vacuum heating furnace for heating at a temperature of 930° C. to 950° C., a heating time of 5 minutes, and a vacuum degree of 10 Pa to austenitize it.

[0087] The heated austenitized sheet is then punched to form a reinforcement plate part;

[0088] Then the stamped reinforcement plate parts are trimmed and holes are cut;

[0089] The trimmed and cut reinforcement plate parts are then sandblasted to remove the oxide scale, thus obtaining the reinforcement plate parts to be plated. The sandblasting pressure is set at 0.2 MPa and 180 mesh alumina sand is used.

[0090] The obtained reinforcement plate parts are then fed to the cyclic vacuum evaporation production line shown in Figure 3 for vacuum evaporation of a zinc-aluminum alloy coating with an aluminum content of 10%. The parts are first placed on the hanger of a vacuum evaporation furnace. The furnace is then rapidly evacuated to a vacuum value of 10-2 Pa. A zinc-aluminum alloy wire is then heated to evaporate the zinc-aluminum alloy layer. During the evaporation process, the reinforcement plate parts are rotated, and the temperature in the vacuum evaporation furnace is maintained at 50°C. The evaporation process lasts 10 minutes, and the thickness of the zinc-aluminum alloy layer after evaporation is 7-10 μm.

[0091] Example 3:

[0092] First, the 1.2 mm A-pillar blank is placed in a nitrogen-protected heating furnace for heating at a temperature of 930° C. to 950° C. for 5 minutes to austenitize it.

[0093] The heated austenitized A-pillar blank is then stamped to form an A-pillar part;

[0094] Then the stamped A-pillar parts are trimmed and cut;

[0095] The A-pillar parts that have been trimmed and cut are then sandblasted to remove the oxide scale, thus obtaining the A-pillar parts to be plated. The sandblasting pressure is set at 0.2 MPa, and 180 mesh alumina sand is used;

[0096] Then, the obtained A-pillar parts to be plated are placed in the continuous vacuum evaporation production line as shown in Figure 2 for vacuum evaporation galvanizing. First, the A-pillar parts to be plated are placed on the hanger of the vacuum evaporation furnace and enter the feed buffer chamber. After the feed buffer chamber reaches the required vacuum degree, open the partition door connected to the vacuum evaporation chamber on the right side to allow it to enter the vacuum evaporation chamber. During the evaporation galvanizing process, the A-pillar parts rotate and move forward. During the evaporation process, the temperature inside the vacuum evaporation furnace is consistent with the room temperature. After 15 minutes of evaporation, open the partition door connecting the vacuum evaporation chamber to the discharge buffer chamber on its right side to allow the A-pillar parts to enter the discharge buffer chamber. After the evaporation is completed, break the vacuum, open the discharge door of the discharge buffer chamber, and take out the evaporated parts. The thickness of the galvanized layer on the surface of the A-pillar parts after evaporation is 10um-13um.

[0097] As shown in FIG4, FIG7 and Table 1, the coating thickness uniformity test was performed on the parts after the evaporation deposition in Examples 1-3, and the test results are as follows:

[0098] Table 1 Test results of coating thickness uniformity of parts after evaporation in each embodiment

[0099] As can be seen from Table 1, the coating thickness of the vapor-deposited parts in each embodiment is within the preset thickness range, meeting production requirements. It should be understood that the sampling points in the three embodiments are randomly selected;

[0100] As shown in FIG5 , the galvanized layer bonding strength test was performed on the anti-collision beam part in Example 1, and the bonding strength was level 0.

[0101] As shown in Figures 6 and 8, the parts in Example 1 and Example 2 were subjected to salt spray tests. Among them, the anti-collision beam parts in Example 1 did not rust after being in a neutral salt spray environment for 48 hours, and the reinforcing plate parts in Example 2 did not rust after being in a neutral salt spray environment for 68 hours. The parts in the two embodiments are protected by the galvanized layer applied on their surfaces and have excellent corrosion resistance.

[0102] Specifically, this embodiment further provides a device for preparing corrosion-resistant hot stamping parts, which adopts the preparation method described in this embodiment and includes a blanking mechanism, a heating mechanism, a forming mechanism, a vapor deposition pre-treatment mechanism, and a vapor deposition mechanism, wherein:

[0103] The blanking mechanism is used to blank the bare steel plate into a blank of a preset shape;

[0104] The heating mechanism is used to heat the blank formed into a preset shape;

[0105] The forming mechanism is used to form the heated blank into a part;

[0106] The evaporation pre-treatment mechanism is used to perform surface pre-treatment on the formed parts to obtain parts to be plated;

[0107] The evaporation mechanism is used to perform evaporation on the obtained parts to be plated for less than 30 minutes, so that a zinc coating layer or a zinc alloy layer with a thickness greater than 3 μm is formed on the surface.

[0108] Referring to FIG. 9 , the present invention discloses a method for improving the adhesive properties of a vapor-deposited part, comprising the following steps:

[0109] First, the part (to be plated) undergoes surface pretreatment to remove scale, grease, and other surface residues. Specifically, surface pretreatment involves sandblasting or pickling. Sandblasting the formed part not only effectively removes surface scale but also increases surface roughness, which helps improve bonding strength.

[0110] The parts can then be sent to the evaporation mechanism, and the evaporation mechanism can be vacuumed; the parts sent to the evaporation mechanism can then be plasma cleaned to remove organic pollutants on their surfaces; the parts sent to the evaporation mechanism can then be vacuum evaporated to form a coating on the parts. Since the vacuum evaporation process is to accumulate the evaporation material in the form of atoms on the surface of the parts, the coating formed by direct vacuum evaporation will contain many holes and gaps, and the coating as a whole is relatively rough. If the subsequent adhesive baking process is carried out directly, the gas in the holes will be released, and a large number of holes will appear in the adhesive layer. Therefore, during the vacuum evaporation process of the parts after plasma cleaning, heating is maintained or the parts are heated after the vacuum evaporation is completed, so that the atoms forming the coating can diffuse, and the gas in the holes will also be discharged due to heat, so that the rough coating will gradually form a dense coating, which can be effectively bonded to the structural adhesive later.

[0111] The material used to form the dense coating is pure zinc or a zinc alloy. Pure zinc is used as the coating material because it has good corrosion resistance. In particular, zinc alloys, such as zinc-aluminum-magnesium alloys, not only have good corrosion resistance but also excellent welding properties. Zinc also has a low evaporation temperature and can usually evaporate at room temperature. Its evaporation rate is fast, making it more suitable for mass production. Specifically, in this embodiment, whether the plasma-cleaned part is heated while being vacuum-deposited, or the plasma-cleaned part is heated after being vacuum-deposited, the heating temperature is controlled to be no greater than 200° C. and the heating time is less than 4 hours. This heating condition allows the atoms forming the coating to diffuse and the gas in the pores of the coating to be discharged by heat, thereby making the coating denser overall. Finally, the surface oxides and other impurities of the part are removed, while increasing its surface activation energy, thereby improving the adhesive properties of the part surface (coating). For example, plasma cleaning or chemical cleaning can be used to remove surface oxides from the parts with dense coatings. When plasma cleaning is used, the parts can be removed from the evaporation mechanism using a plasma cleaning unit provided in the evaporation mechanism. Alternatively, the parts can be removed from the evaporation mechanism after forming a dense coating, and then a plasma cleaning unit provided outside the evaporation mechanism can be used to remove oxides and other impurities from their surfaces. If chemical cleaning is used, for example, a HNO3 solution with a weight percentage concentration of 0.1% to 5% can be used to clean the surfaces of the parts with dense coatings. Preferably, in this embodiment, vacuum evaporation and heating are performed on the parts after plasma cleaning to form a dense coating on the parts' surfaces. Alternatively, after vacuum evaporation and heating are performed on the parts after plasma cleaning to form a dense coating on the parts' surfaces, the evaporation mechanism is vacuumed for a predetermined period of time, and then plasma cleaning or pickling is performed to remove oxides and other impurities from the parts' surfaces. The reason is that after vacuum evaporation is completed, a large amount of atomic vapor is contained in the vacuum chamber of the evaporation mechanism. If the vacuum chamber is opened immediately, the atomic vapor will quickly oxidize and adhere to the surface of the part, affecting its performance.

[0112] The present embodiment is described in detail below through specific embodiments:

[0113] Example 4:

[0114] First, the hot stamped door sill parts are sandblasted to remove the oxide scale on their surface;

[0115] Then, the door sill part is sent into the evaporation mechanism, and the evaporation mechanism is evacuated to a vacuum degree of 10-3 Pa in the vacuum chamber;

[0116] The threshold component is then plasma cleaned using an ion source with an acceleration voltage of 5 kV and a rated power of 10 kVA at 45% output power for 10 minutes. During this process, the threshold component is rotated to ensure that it is thoroughly cleaned.

[0117] Then, the door sill is subjected to vacuum evaporation treatment, wherein the material used to form the coating is pure zinc, the evaporation time is 30 minutes, and the thickness of the formed dense coating (zinc layer) is 6-10 μm;

[0118] Then, the evaporation power supply is turned off to stop the vacuum evaporation, and the evaporation mechanism is continuously vacuumed for 30 minutes;

[0119] Then, the vacuum chamber of the evaporation mechanism is opened, and the threshold part is placed in a heating furnace and heated at 200° C. for 2 hours.

[0120] Finally, the heated door sill surface was cleaned using a plasma cleaning chamber to remove oxides and improve surface adhesion. The operating voltage of the plasma cleaning chamber was set to 8 kV, the cleaning time was set to 3 minutes, and the working gas was argon.

[0121] Example 5:

[0122] First, the hot stamping door sill parts are subjected to surface pretreatment such as degreasing and pickling to remove grease and oxide scale on the surface;

[0123] Then, the door sill part is sent into the evaporation mechanism, and the evaporation mechanism is evacuated to a vacuum degree of 10-3 Pa in the vacuum chamber;

[0124] The threshold is then plasma cleaned using an ion source with an acceleration voltage of 5 kV and a rated power of 10 kVA at 40% output power for 15 minutes. During this process, the threshold is rotated to ensure thorough cleaning.

[0125] The threshold part is then subjected to a vacuum evaporation treatment, wherein the material used to form the coating is a zinc-aluminum-magnesium alloy. The threshold part is heated to 150° C. during the vacuum evaporation treatment, and the evaporation time is 25 minutes. The thickness of the formed dense coating (zinc-aluminum-magnesium alloy layer) is 5-10 μm.

[0126] Then, the evaporation power supply is turned off to stop the vacuum evaporation, and then the evaporation mechanism is continuously vacuumed for 30 minutes;

[0127] Finally, the threshold surface was plasma cleaned again using the plasma cleaning unit within the deposition mechanism to remove oxides and improve surface adhesion. During this process, the accelerating voltage was 5kV, and the ion source, rated at 10kVA, was set at 45% output power for 10 minutes. The threshold remained in a rotating state.

[0128] Example 6:

[0129] First, the hot stamped door sill parts are sandblasted to remove the surface oxide scale;

[0130] Then, the door sill part is sent into the evaporation mechanism, and the evaporation mechanism is evacuated to a vacuum degree of 10-3 Pa in the vacuum chamber;

[0131] The threshold component is then plasma cleaned using an ion source with an acceleration voltage of 5 kV and a rated power of 10 kVA at 40% output power for 15 minutes. During this process, the threshold component is rotated to ensure that it is thoroughly cleaned.

[0132] Then, the door sill is subjected to vacuum evaporation treatment, wherein the material used to form the coating is zinc-aluminum-magnesium alloy, the evaporation time is 20 minutes, and the thickness of the formed dense coating (zinc-aluminum-magnesium alloy layer) is 3-5 μm;

[0133] Then, the evaporation power supply is turned off to stop the vacuum evaporation, and then the evaporation mechanism is continuously vacuumed for 30 minutes;

[0134] Then, the vacuum chamber was opened, and the threshold component was taken out and placed in a heating furnace for heating at 200° C. for 2 h.

[0135] Finally, a manual plasma cleaning device is used to perform plasma cleaning on the heated threshold parts where glue is required to be applied, so as to remove oxides on the surface and improve the surface adhesive properties. During this process, the operating voltage of the manual plasma cleaning device is set to 6KV, the plasma cleaning time is set to 1 minute, nitrogen is used as the protective gas, and the gas pressure is 0.2Mpa.

[0136] Example 7:

[0137] First, the hot stamped door sill parts are sandblasted to remove the surface oxide scale;

[0138] Then, the door sill part is sent into the evaporation mechanism, and the evaporation mechanism is evacuated to a vacuum degree of 10-3 Pa in the vacuum chamber;

[0139] The threshold is then plasma cleaned using an ion source with an acceleration voltage of 5 kV and a rated power of 10 kVA at 40% output power for 15 minutes. During this process, the threshold is rotated to ensure thorough cleaning.

[0140] Then, the door sill is subjected to vacuum evaporation treatment, wherein the material used to form the coating is zinc-aluminum-magnesium alloy, the evaporation time is 30 minutes, and the formed dense coating (zinc-aluminum-magnesium alloy layer) has a thickness of 6-10 μm;

[0141] Then, the evaporation power supply is turned off to stop the vacuum evaporation, and then the evaporation mechanism is continuously vacuumed for 30 minutes;

[0142] Then, the vacuum chamber is opened, and the threshold part is placed in a heating furnace and heated at 200 degrees for 2 hours.

[0143] Finally, the threshold part was placed in a 0.5% HNO3 solution and soaked for 10 seconds to remove the oxide on its surface.

[0144] Adhesion performance tests were conducted on door sill parts from the same batch as in Examples 4-7, which had undergone surface pretreatment and were subsequently fed into the evaporation mechanism. The evaporation mechanism was then evacuated, plasma cleaned, and then vapor-deposited with the same coating, but not heated. As shown in Figure 9 , the adhesion between the surface and the structural adhesive was extremely poor, with numerous pores forming in the structural adhesive.

[0145] As shown in Figures 10 and 11 , the same batch of door sills as in Examples 4-7, which had undergone surface pretreatment and were subsequently fed into the vapor deposition mechanism, were vacuumed, plasma cleaned, and then vapor-deposited with the same coating and heated. Adhesion performance tests were conducted on these door sills. The adhesion between the door sills and the structural adhesive was significantly improved, but still did not meet the acceptable standards.

[0146] The door sill part obtained in Example 4-7 was subjected to an adhesive performance test, that is, the structural adhesive was normally bonded to the coating surface. The test results are shown in FIG12 , and the adhesive area was 100%, indicating that the adhesive performance was qualified.

[0147] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any changes, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing corrosion-resistant hot stamping parts, characterized in that: The following steps are involved: Blanking the bare board into blanks of preset shapes; The blank is sent into a heating furnace for heating to austenitize the blank; placing the austenitized blank into a die for stamping to form it into a part; Performing surface pretreatment on the formed parts to obtain parts to be plated; The obtained parts to be plated are subjected to evaporation for less than 30 minutes to form a zinc plating layer or a zinc alloy layer with a thickness greater than 3 um on the surface.

2. The method for preparing corrosion-resistant hot stamping parts according to claim 1, characterized in that: The thickness of the zinc coating is 5um-13um.

3. The method for preparing corrosion-resistant hot stamping parts according to claim 1, characterized in that: In the step of "performing evaporation on the obtained parts to be plated for less than 30 minutes to form a zinc coating or zinc alloy layer with a thickness greater than 3 um on the surface", the evaporation time of the parts to be plated is 3 minutes to 10 minutes.

4. The method for preparing corrosion-resistant hot stamping parts according to claim 1, characterized in that: The step of "performing evaporation on the obtained part to be plated for less than 30 minutes to form a zinc coating or zinc alloy coating with a thickness greater than 3 um on the surface thereof" includes: Sending the obtained parts to be plated into a vapor deposition mechanism; Vacuuming the evaporation mechanism; Performing evaporation on the parts to be plated sent into the evaporation mechanism to obtain parts with a zinc coating or a zinc alloy coating formed on the surface; The evaporation mechanism is subjected to vacuum breaking to obtain parts with a zinc-plated layer or a zinc alloy layer on the surface.

5. The method for preparing corrosion-resistant hot stamping parts according to claim 4, characterized in that: In the step of "evaporating the parts to be plated which are fed into the evaporation mechanism to obtain parts with a zinc coating or a zinc alloy coating formed on the surface", the parts to be plated are in a rotating state.

6. The method for preparing corrosion-resistant hot stamping parts according to claim 4, characterized in that: In the step of "evaporating the parts to be plated which are fed into the evaporation mechanism to obtain parts with a zinc coating or a zinc alloy coating formed on the surface", the temperature of the parts to be plated is less than 200°C.

7. The method for preparing corrosion-resistant hot stamping parts according to claim 6, characterized in that: The temperature of the parts to be plated is less than 50°C.

8. The method for preparing corrosion-resistant hot stamping parts according to claim 1, characterized in that: In the step of "blanking the bare plate into a blank of a preset shape", the bare plate is a hot-formed bare steel plate with a strength of not less than 1500 MPa.

9. The method for preparing corrosion-resistant hot stamping parts according to claim 8, characterized in that: The strength of the hot-formed bare steel plate is 1500MPa or 2000MPa.

10. The method for preparing corrosion-resistant hot stamping parts according to claim 1, characterized in that: In the step of "sending the blank into a heating furnace for heating to austenitize the blank", the heating furnace includes a vacuum heating furnace or an atmosphere heating furnace, and the oxygen content in the heating furnace is less than 0.01%.

11. The method for preparing corrosion-resistant hot stamping parts according to claim 10, characterized in that: The vacuum degree in the vacuum heating furnace is less than 100Pa.

12. The method for preparing corrosion-resistant hot stamping parts according to claim 11, characterized in that: The vacuum degree in the vacuum heating furnace is 1Pa-10Pa.

13. The method for preparing corrosion-resistant hot stamping parts according to claim 1, characterized in that: In the step of "subjecting surface pretreatment to the molded part to obtain a part to be plated", the surface pretreatment includes sandblasting or pickling the molded part.

14. The method for preparing corrosion-resistant hot stamping parts according to claim 13, characterized in that: Before sandblasting or pickling the formed parts, the parts are also laser trimmed or cut.

15. A device for preparing corrosion-resistant hot stamping parts, which adopts the preparation method according to any one of claims 1 to 14, characterized in that: It includes a blanking mechanism, a heating mechanism, a molding mechanism, a vapor deposition pre-treatment mechanism and a vapor deposition mechanism, wherein: The blanking mechanism is used to blank the bare steel plate into a blank of a preset shape; The heating mechanism is used to heat the blank formed into a preset shape; The forming mechanism is used to form the heated blank into a part; The evaporation pre-treatment mechanism is used to perform surface pre-treatment on the formed parts to obtain parts to be plated; The evaporation mechanism is used to perform evaporation on the obtained parts to be plated for a period of less than 30 minutes, so that a zinc coating layer or a zinc alloy layer with a thickness greater than 3 um is formed on the surface.

16. A method for improving the adhesive properties of a vapor deposited part, characterized in that: The following steps are involved: Send the parts into the evaporation mechanism and evacuate the evaporation mechanism; Plasma cleaning is performed on the parts sent into the evaporation mechanism; Vacuum evaporation and heating are performed on the plasma cleaned part to form a dense coating on the surface of the part; or, The plasma-cleaned parts are vacuum-deposited and then heated to form a dense coating on the surface of the parts.

17. The method for improving the adhesive properties of a vapor deposited part according to claim 16, characterized in that: In step ", vacuum evaporation and heating are performed on the plasma cleaned part to form a dense coating on the surface of the part; Or, the part after plasma cleaning is vacuum evaporated and then heated to form a dense coating on the surface of the part", and the material used to form the dense coating is pure zinc or zinc alloy.

18. The method for improving the adhesive properties of a vapor deposited part according to claim 16, characterized in that: In step ", vacuum evaporation and heating are performed on the plasma cleaned part to form a dense coating on the surface of the part; Or, the part after plasma cleaning is vacuum evaporated and then heated to form a dense coating on the surface of the part", the heating temperature is not greater than 200°C and the heating time is less than 4h.

19. The method for improving the adhesive properties of a vapor deposited part according to claim 16, characterized in that: In step ", vacuum evaporation and heating are performed on the plasma cleaned part to form a dense coating on the surface of the part; Alternatively, the plasma-cleaned part is subjected to vacuum evaporation and then heated to form a dense coating on the surface of the part, and then the surface oxide of the part is removed.

20. The method for improving the adhesive properties of a vapor deposited part according to claim 19, characterized in that: The surface oxides of the parts are removed by plasma cleaning.

21. The method for improving the adhesive properties of a vapor deposited part according to claim 20, characterized in that: A plasma cleaning method is used in the evaporation mechanism or outside the evaporation mechanism to remove surface oxides of the parts.

22. The method for improving the adhesive properties of a vapor deposited part according to claim 19, characterized in that: The surface oxides of the parts are removed by chemical cleaning.

23. The method for improving the adhesive properties of a vapor deposited part according to claim 22, characterized in that: The surface oxides of the parts are removed by using HNO3 solution with a concentration of 0.1% to 5% by weight.

24. The method for improving the adhesive properties of a vapor deposited part according to claim 16, characterized in that: In step ", vacuum evaporation and heating are performed on the plasma cleaned part to form a dense coating on the surface of the part; Alternatively, the plasma-cleaned part is subjected to vacuum evaporation and then heated to form a dense coating on the surface of the part, and the evaporation mechanism is further vacuumed for a preset period of time.

25. The method for improving the adhesive properties of a vapor deposited part according to claim 16, characterized in that: Before the step of "sending the parts into the evaporation mechanism and evacuating the evaporation mechanism", the parts are also subjected to surface pretreatment.

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