Surface treatment method for low-temperature-resistant high-toughness threaded rod

Abstract

The invention relates to the technical field of threaded rods, and discloses a low-temperature-resistant high-toughness threaded rod surface treatment method which comprises the following steps: S1, burdening: selecting materials, and blanking according to a given specification and length; s2, material cutting is conducted, specifically, the blanked metal rod is cut into metal rods with the required specified length; s3, heat treatment is conducted, specifically, the metal rod obtained in the S2 is subjected to heat treatment to form a threaded rod rough blank; s4, thread rolling is conducted, specifically, the quenched threaded rod rough blank is subjected to machining and thread rolling, and a threaded rod main body is obtained; s5, surface treatment: carrying out surface treatment on the threaded rod rough blank; s6, ammoniation is conducted, specifically, the threaded rod body is placed in a gas nitriding furnace to be subjected to nitriding treatment; s7, electroplating is conducted, specifically, the nitrided threaded rod body is electroplated to obtain the low-temperature high-toughness threaded rod, the toughness of the threaded rod is improved through the nitriding technology, residual compressive stress generated on the surface after nitriding can offset part of tensile stress under fatigue loads, and therefore the fatigue strength is reduced, and the threaded rod can also be used in a high-load state.

Description

Technical Field

[0001] The invention belongs to the technical field of tooth bars, and in particular relates to a surface treatment method for a low-temperature resistant and high-toughness tooth bar. Background Art

[0002] The name of the furniture part, namely the tooth, is also called the lead screw, and the name is different due to different positions. Generally, it refers to the part set under the face frame to connect the two legs. For furniture with a waist, the main connecting part is below the waist, and the parts set in other parts are generally called tooth bars. The tooth bars of the existing technology cannot withstand low temperatures, which makes it easy to break when used at low temperatures. For this reason, we propose a surface treatment method for tooth bars with high toughness and low temperature resistance. Summary of the invention

[0003] The purpose of the present invention is to solve the problems existing in the prior art and to propose a surface treatment method for a low-temperature resistant and high-toughness tooth rod.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A method for treating the surface of a low-temperature-resistant and high-toughness tooth rod comprises the following steps:

[0006] S1: batching, selecting materials and cutting them according to given specifications and lengths;

[0007] S2: Cutting the metal rod into the required length to obtain the metal rod;

[0008] S3: heat treatment, heat treating the metal rod obtained in S2 to form a rough tooth bar blank;

[0009] S4: thread rolling, processing and thread rolling the quenched tooth bar blank to obtain the tooth bar body;

[0010] S5: surface treatment, surface treatment of the rough tooth blank;

[0011] S6: ammoniation, placing the tooth rod body into a gas nitriding furnace for nitriding treatment;

[0012] S7: electroplating, electroplating the nitrided tooth bar body to obtain a low-temperature high-toughness tooth bar.

[0013] Preferably, the tooth bar material is formulated according to the following raw material powder mass fraction ratio: Mo: 17-55%, FeB: 10-40%, Cr: 3-10%, Ce: 0.2-2%, Ni: 2-10%, Nb: 1-4%, Mn: 1-7%, C: 0.1-1%, B2: 2-7%, Cr: 4-10%, C0: 1-3%, Cu: 0.1-0.7%, V0: 4-6%, Si: 0.2-0.4%, W0: 4-6%, Mn: 5-15%, Ta: 1-4%, Ai: 1-4%, modified phenolic resin adhesive: 2-7%, Fe: balance.

[0014] Preferably, the tooth bar material is produced in the following manner: S1. Mold making: according to the required length of the alloy screw to be made, a pipe of corresponding length is selected to make the corresponding mold; S2. Blank making: the raw materials are weighed and distributed according to the ratio, and then each portion of the raw materials is placed in a container, stirred and mixed, and after uniform mixing, the mixture is poured into the mold and compacted, and the inside of the mold is made into a vacuum state; S3. Normalizing: the prepared blank is placed in a calcining furnace and sintered at a temperature of 105-110°C to obtain a blank, and then the blank is normalized in the furnace, wherein the normalizing treatment is performed 2 to 3 times; S5: the screw blank after normalizing is then sintered using a vacuum liquid phase sintering process, the sintering temperature is 260-400°C, the heating rate is 10-20°C / min, and the insulation time is 30-80min after reaching the predetermined temperature.

[0015] Preferably, the modified phenolic resin adhesive comprises the following components in parts by weight: 100-200 parts of aldehyde, 0.1-0.25 parts of acid, 2-4 parts of methyl glucoside, 15-22 parts of multi-walled carbon nanotubes, 1-3 parts of dialdehyde, 75-85 parts of bismaleimide-modified phenolic resin, 10-18 parts of γ-aminopropyltriethoxysilane surface-modified graphene oxide, 20-30 parts of polyurethane resin, 1-2 parts of antioxidant, and 2-5 parts of aluminum oxide particles.

[0016] Preferably, the S2 metal rod is heated for austenitization at a temperature of 950-1050°C, kept warm for 2-3h, and air-cooled after being taken out of the furnace. A fan is used to blow the metal rod during the air cooling process. The metal rod is then heated to 900-950°C again, furnace-cooled to 600-650°C, and then quickly placed in a quenching device for quenching. The metal rod is taken out after the surface temperature drops to 300-350°C, and then tempered in the quenching device at a tempering temperature of 380-450°C, a tempering time of 60-95min, kept warm for 1-2h, and finally cooled to room temperature.

[0017] Preferably, the method for surface treatment of the tooth bar rough blank in S5 is soaking in a detergent for 5-15 minutes. The detergent is prepared by mixing the following raw materials: 20-30% sodium silicate, 20-30% deionized water, 5-10% soda ash, 10-20% ethanol, and 30-40% distilled water to achieve metal surface heat treatment and rust removal. The temperature of the detergent is 50-85°C.

[0018] Preferably, the nitriding treatment step in S6 is: first, the tooth bar body is placed in a heating furnace and heated to 500-535°C, the furnace pressure is 0.02-0.10Pa, and the temperature is kept for 1-1.5h, then the nitrogen valve is closed, and air is introduced, and the metal mold is pre-oxidized for 5-10min with the help of oxygen in the air and the furnace temperature, and the tooth bar body after pre-oxidation is directly transferred to a glow ion nitriding furnace for ion nitriding treatment, and the nitriding decomposition rate is controlled between 20-28%, and the temperature is increased in an argon atmosphere. When the mold temperature reaches 550-670°C, it is kept warm for 22-26h, and then the temperature is increased again to 570-590°C, and the nitriding decomposition rate is controlled between 50-55%, and the temperature is kept for 53-56h. Then, the tooth bar body is further heated to 590-610°C, and the nitriding decomposition rate is controlled between 90-95%, and the temperature is kept for 2-4h.

[0019] Preferably, the electroplating process in S8 comprises the following steps:

[0020] S1, raw material preparation: pour the following three raw materials into three electroplating tanks respectively in the electroplating box;

[0021] S2, putting the tooth rod body into the electroplating box: after the electroplating device is powered on, the electroplating solution is heated, and the workpiece is electroplated three times. After each electroplating, it needs to be dehydrated and air-dried.

[0022] Preferably, the electroplating solution placed in the first electroplating tank is composed of the following raw materials: 15-70 parts of deionized water, 10-50 parts of anti-rust film-forming agent, 3-12 parts of anti-rust additive, 0.5-2 parts of leveling agent, 1.5-5 parts of silane coupling agent, and 1-2 parts of thickener;

[0023] The electroplating solution placed in the second electroplating tank is composed of the following raw materials: 18-22 parts of basic copper carbonate, 12-25 parts of aminosulfonic acid, 5-10 parts of potassium sulfate, 50-150 parts of distilled water, 5-10 parts of potassium nitrate, and 0.1-0.2 parts of brightener;

[0024] The electroplating solution placed in the third electroplating tank is composed of the following raw materials: 4-15 parts of nickel sulfate, 2-5 parts of nickel sulfamate, 1-3 parts of reducing agent, 0.3-0.6 parts of stabilizer, 1-3 parts of 2-5% organic acid, 0.01-0.03 parts of alkyl sulfonate, 0.01-0.03 parts of alkylphenol sulfonate, 0.01-0.03 parts of alkylphenol sulfate, 0.2-0.5 parts of titanium dioxide, and 20-30 parts of deionized water.

[0025] Preferably, the workpiece is electroplated three times at the following current density, electroplating solution temperature and electroplating time:

[0026] First time: the current density is 1.0-2.0A / dm 2 , the plating solution temperature is 45-50℃, and the plating time is 4-6min;

[0027] Second time: the current density is 1.4-1.8A / dm 2 , the plating solution temperature is 40-50℃, and the plating time is 7-12min;

[0028] The third time: the current density is 0.8-1.0A / dm 2 , the plating solution temperature is 30-50℃, and the plating time is 10-20min.

[0029] Compared with the prior art, the present invention provides a surface treatment method for a low-temperature resistant and high-toughness tooth rod, which has the following beneficial effects:

[0030] 1. The present invention improves the toughness of the tooth bar through the nitriding process. The residual compressive stress generated on the surface after nitriding can offset part of the tensile stress under fatigue load, thereby reducing fatigue strength, so that the tooth bar can be used even in a high load state;

[0031] 2. The present invention adopts multiple electroplating to prevent metal oxidation, such as rust, improve metal corrosion resistance, effectively resist external friction and wear, and thus reduce the possibility of damage to the tooth bar during long-term use. At the same time, the electroplating layer can provide a certain lubricity, making the hardware products smoother during processing;

[0032] 3. The invention improves the processing performance of the tooth bar, removes the internal stress of the material, stabilizes the size of the workpiece, prevents deformation and cracking, and thus increases the service life of the screw;

[0033] 4. The present invention improves the production process of tooth bars at the raw material level, thereby making the tooth bars more stable when used in a low-temperature environment, reducing the stress of the tooth bars, improving the safety of the tooth bars, and expanding the scope of use of the tooth bars. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0035] In the attached picture:

[0036] Figure 1 The invention discloses a surface treatment method for a low-temperature-resistant and high-toughness tooth rod. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0038] Embodiment 1:

[0039] See also Figure 1 , a low temperature resistant and high toughness tooth rod surface treatment method, comprising the following steps:

[0040] S1: batching, selecting materials, cutting according to given specifications and lengths, mold making: selecting pipes of corresponding lengths according to the required length of the alloy screw to be made, so as to make corresponding molds, making blanks: weighing and distributing the raw materials according to the proportions, selecting raw materials Mo: 33%, FeB: 22%, Cr: 5%, Ce: 1%, Ni: 3%, Nb: 2%, Mn: 2%, C: 0.2%, B2: 2.5%, Cr: 5%, C0: 1.2%, Cu: 0.5%, V0: 5%, Si: 0.3%, W0: 5%, Mn: 5%, Ta: 2%, Ai: 3%, modified phenolic resin binder: 2%, Fe: balance, wherein the modified phenolic resin binder comprises the following components in parts by weight: 150 parts of aldehyde, 0.25 parts of acid, methyl glucose 4 parts of glycosides, 22 parts of multi-walled carbon nanotubes, 1 part of dialdehyde, 75 parts of bismaleimide-modified phenolic resin, 10 parts of γ-aminopropyltriethoxysilane surface-modified graphene oxide, 30 parts of polyurethane resin, 1 part of antioxidant, 4 parts of aluminum oxide particles, then put each part of the raw materials into a container, stir and mix, pour the mixture into a mold after uniform mixing, and compact it, and make the inside of the mold into a vacuum state, normalizing treatment: put the prepared blank into a calcining furnace, sinter it at a temperature of 110°C, so as to obtain a blank, and then normalize the blank in a furnace, wherein the normalizing treatment is performed twice, and then the screw blank after normalizing treatment is subjected to a vacuum liquid phase sintering process, the sintering temperature is 300°C, the heating rate is 18°C / min, and the holding time is 45min after reaching the predetermined temperature;

[0041] S2: Cutting the metal rod into the required length to obtain the metal rod;

[0042] S3: heat treatment, heat treating the metal rod obtained in S2 to form a rough tooth bar blank, heating the metal rod for austenitization, the austenitization temperature is 1050°C, keeping it at this temperature for 3 hours, air cooling after being taken out of the furnace, blowing it with a fan during the air cooling process, then heating the metal rod again to 950°C, cooling it to 650°C by furnace, and then quickly putting it into a quenching device for quenching, taking it out after the surface temperature drops to 350°C, and then tempering the metal rod in the quenching device, the tempering temperature is 410°C, the tempering time is 65min, keeping it at this temperature for 2 hours, and finally cooling it to room temperature;

[0043] S4: thread rolling, processing and thread rolling the quenched tooth bar blank to obtain the tooth bar body;

[0044] S5: Surface treatment: soak the tooth bar blank in a cleaning agent for 5-15 minutes. The cleaning agent is prepared by mixing the following raw materials: 20% sodium silicate, 20% deionized water, 5% soda ash, 20% ethanol, and 35% distilled water to achieve heat treatment and rust removal on the metal surface. The cleaning agent temperature is 85°C.

[0045] S6: ammoniating, placing the tooth bar body into a gas nitriding furnace for nitriding treatment. The tooth bar body is placed into a heating furnace and heated to 500-535°C, with a furnace pressure of 0.02-0.10Pa, and kept warm for 1-1.5 hours. Then the nitrogen valve is closed and air is introduced. The metal mold is pre-oxidized for 5-10 minutes with the help of oxygen in the air and the furnace temperature. The tooth bar body after pre-oxidation is directly transferred to a glow ion nitriding furnace for ion nitriding treatment. The nitriding decomposition rate is controlled between 25%. The temperature is increased in an argon atmosphere. When the mold temperature reaches 560°C, it is kept warm for 24 hours, and then the temperature is increased to 580°C again, and the nitriding decomposition rate is controlled between 55%, and the temperature is kept warm for 54 hours. Then the tooth bar body is further heated to 590°C, and the nitriding decomposition rate is controlled at 90%, and the temperature is kept warm for 4 hours.

[0046] S7: electroplating, electroplating the nitrided tooth bar body to obtain a low-temperature high-toughness tooth bar, pouring the following three raw materials into three electroplating tanks of the electroplating box respectively, the electroplating solution placed in the first electroplating tank is composed of the following raw materials: 55 parts of deionized water, 30 parts of anti-rust film-forming agent, 8 parts of anti-rust additive, 2 parts of leveling agent, 3 parts of silane coupling agent, 1 part of thickener, the electroplating solution placed in the second electroplating tank is composed of the following raw materials: 20 parts of basic copper carbonate, 21 parts of aminosulfonic acid, 7 parts of potassium sulfate, 111 parts of distilled water, 8 parts of potassium nitrate, 0.1 part of brightener, and the electroplating solution placed in the third electroplating tank is composed of the following raw materials: sulfur 9 parts of nickel sulfate, 4 parts of nickel sulfamate, 2 parts of reducing agent, 0.4 parts of stabilizer, 2 parts of 3% organic acid, 0.015 parts of alkyl sulfonate, 0.018 parts of alkylphenol sulfonate, 0.014 parts of alkylphenol sulfate, 0.4 parts of titanium dioxide, 22 parts of deionized water, pour the above plating solution into the solution pool of the electroplating device, and then put the tooth bar body into the electroplating box: after the electroplating device is powered on, the plating solution is heated, and the workpiece is electroplated three times. After each electroplating, it needs to be dehydrated and air-dried. The workpiece is electroplated three times with current density, plating solution temperature and electroplating time as follows: the first time: the pole current density is 2A / dm 2 , the plating solution temperature is 45℃, the plating time is 5min, the second time: the polar current density is 1.7A / dm 2 , the plating solution temperature is 48℃, the plating time is 8min, the third time: the polar current density is 1.0A / dm 2 , the plating solution temperature is 40℃ and the plating time is 15min.

[0047] Embodiment 2:

[0048] See also Figure 1 , a low temperature resistant and high toughness tooth rod surface treatment method, comprising the following steps:

[0049] S1: batching, selecting materials, cutting according to given specifications and lengths, mold making: selecting corresponding lengths of pipes according to the required length of the alloy screw to be made, so as to make corresponding molds, making blanks: weighing and distributing the raw materials according to the proportion, selecting raw materials Mo: 30%, FeB: 20%, Cr: 5%, Ce: 2%, Ni: 2%, Nb: 2%, Mn: 2%, C: 1%, B2: 4%, Cr: 5%, C0: 2%, Cu: 0.3%, V0: 4%, Si: 0.3%, W0: 4%, Mn: 6%, Ta: 3%, Ai: 2%, modified phenolic resin binder: 2%, Fe: balance, wherein the modified phenolic resin binder comprises the following components in parts by weight: 150 parts of aldehyde, 0.2 parts of acid, 3 parts of methyl glucoside, 17 parts of multi-walled carbon nanotubes, 2 parts of dialdehyde, 80 parts of bismaleimide-modified phenolic resin, 15 parts of γ-aminopropyltriethoxysilane surface-modified graphene oxide, 23 parts of polyurethane resin, 1 part of antioxidant, 4 parts of aluminum oxide particles, then put each part of the raw materials into a container, stir and mix, pour the mixture into a mold after uniform mixing, and compact it, and make the inside of the mold into a vacuum state, normalizing treatment: put the prepared blank into a calcining furnace, sinter it at a temperature of 108°C, so as to obtain a blank, and then normalize the blank in a furnace, wherein the normalizing treatment is performed 3 times, and then the screw blank after normalizing treatment is subjected to a vacuum liquid phase sintering process, the sintering temperature is 300°C, the heating rate is 15°C / min, and the holding time is 55min after reaching the predetermined temperature;

[0050] S2: Cutting the metal rod into the required length to obtain the metal rod;

[0051] S3: heat treatment, heat treating the metal rod obtained in S2 to form a rough tooth bar blank, heating the metal rod for austenitization, the austenitization temperature is 1050°C, keeping it at this temperature for 2.5 hours, air cooling after being taken out of the furnace, blowing it with a fan during the air cooling process, then heating the metal rod again to 950°C, cooling it to 650°C by furnace, and then quickly putting it into a quenching device for quenching, taking it out after the surface temperature drops to 300°C, and then tempering the metal rod in the quenching device, the tempering temperature is 450°C, the tempering time is 60min, keeping it at this temperature for 2 hours, and finally cooling it to room temperature;

[0052] S4: thread rolling, processing and thread rolling the quenched tooth bar blank to obtain the tooth bar body;

[0053] S5: Surface treatment: soak the tooth bar blank in a cleaning agent for 11 minutes. The cleaning agent is prepared by mixing the following raw materials: 20% sodium silicate, 20% deionized water, 10% soda ash, 10% ethanol, and 40% distilled water to achieve heat treatment and rust removal on the metal surface. The cleaning agent temperature is 85°C.

[0054] S6: ammoniating, placing the tooth bar body into a gas nitriding furnace for nitriding treatment, placing the tooth bar body into a heating furnace and heating it to 535°C, with a furnace pressure of 0.10Pa, keeping it warm for 1.5 hours, then closing the nitrogen valve and introducing air, using the oxygen in the air and the furnace temperature to pre-oxidize the metal mold for 10 minutes, directly transferring the tooth bar body after pre-oxidation treatment to a glow ion nitriding furnace for ion nitriding treatment, controlling the nitriding decomposition rate to be between 20%, heating in an argon atmosphere, and keeping it warm when the mold temperature reaches 550°C, keeping it warm for 22 hours, then heating it again to 590°C, controlling the nitriding decomposition rate to be between 50-55%, keeping it warm for 56 hours, then further heating the tooth bar body to 610°C, controlling the nitriding decomposition rate to be between 95%, and keeping it warm for 3 hours;

[0055] S7: electroplating, electroplating the nitrided tooth bar body to obtain a low-temperature high-toughness tooth bar, pouring the following three raw materials into three electroplating tanks of the electroplating box respectively, the electroplating solution placed in the first electroplating tank is composed of the following raw materials: 40 parts of deionized water, 30 parts of anti-rust film-forming agent, 8 parts of anti-rust additive, 2 parts of leveling agent, 1.5 parts of silane coupling agent, 1-2 parts of thickener, the electroplating solution placed in the second electroplating tank is composed of the following raw materials: 22 parts of basic copper carbonate, 18 parts of aminosulfonic acid, 10 parts of potassium sulfate, 90 parts of distilled water, 10 parts of potassium nitrate, 0.2 parts of brightener, and the electroplating solution placed in the third electroplating tank is composed of the following raw materials: Composition: 8 parts of nickel sulfate, 4 parts of nickel sulfamate, 2 parts of reducing agent, 0.6 parts of stabilizer, 2 parts of 4% organic acid, 0.03 parts of alkyl sulfonate, 0.03 parts of alkylphenol sulfonate, 0.02 parts of alkylphenol sulfate, 0.3 parts of titanium dioxide, 24 parts of deionized water. Pour the above plating solution into the solution pool of the electroplating device, and then put the tooth bar body into the electroplating box: After the electroplating device is powered on, the plating solution is heated, and the workpiece is electroplated three times. After each electroplating, it needs to be dehydrated and air-dried. The workpiece is electroplated three times. The current density, plating solution temperature and electroplating time are as follows: The first time: the pole current density is 1.8A / dm 2 , the plating solution temperature is 45℃, the plating time is 5min, the second time: the polar current density is 1.5A / dm 2 , the plating solution temperature is 50℃, the plating time is 9min, the third time: the polar current density is 0.9A / dm 2 , the plating solution temperature is 40℃ and the plating time is 18min.

[0056] Embodiment 3:

[0057] See also Figure 1 , a low temperature resistant and high toughness tooth rod surface treatment method, comprising the following steps:

[0058] S1: batching, selecting materials, cutting according to given specifications and lengths, mold making: selecting pipes of corresponding lengths according to the required length of the alloy screw to be made, so as to make corresponding molds, making blanks: weighing and distributing the raw materials according to the proportions, selecting raw materials Mo: 33%, FeB: 13%, Cr: 5%, Ce: 1%, Ni: 3%, Nb: 4%, Mn: 2%, C: 0.3%, B2: 4%, Cr: 4%, C0: 2%, Cu: 0.3%, V0: 5%, Si: 0.4%, W0: 4%, Mn: 6%, Ta: 3%, Ai: 3%, modified phenolic resin binder: 4%, Fe: balance, wherein the modified phenolic resin binder comprises the following components in parts by weight: 150 parts of aldehyde, 0.2 parts of acid, 3 parts of methyl glucoside , 18 parts of multi-walled carbon nanotubes, 2 parts of dialdehyde, 80 parts of bismaleimide-modified phenolic resin, 15 parts of γ-aminopropyltriethoxysilane surface-modified graphene oxide, 24 parts of polyurethane resin, 1 part of antioxidant, 3 parts of aluminum oxide particles, then put each raw material into a container, stir and mix, pour the mixture into a mold after uniform mixing, and compact it, and make the inside of the mold into a vacuum state, normalizing treatment: put the prepared blank into a calcining furnace for sintering, wherein the temperature is 108°C, so as to obtain a blank, and then normalize the blank in a furnace, wherein the normalizing treatment is performed 3 times, and then the screw blank after normalizing treatment is subjected to a vacuum liquid phase sintering process, the sintering temperature is 300°C, the heating rate is 15°C / min, and the holding time is 40min after reaching the predetermined temperature;

[0059] S2: Cutting the metal rod into the required length to obtain the metal rod;

[0060] S3: heat treatment, heat treating the metal rod obtained in S2 to form a tooth bar blank, heating the metal rod for austenitization, the austenitization temperature is 1000°C, keeping it at this temperature for 3 hours, air cooling after being taken out of the furnace, blowing it with a fan during the air cooling process, then heating the metal rod again to 930°C, cooling it to 630°C by furnace, and then quickly putting it into a quenching device for quenching, taking it out after the surface temperature drops to 350°C, and then tempering the metal rod in the quenching device, the tempering temperature is 430°C, the tempering time is 88min, keeping it at this temperature for 2 hours, and finally cooling it to room temperature;

[0061] S4: thread rolling, processing and thread rolling the quenched tooth bar blank to obtain the tooth bar body;

[0062] S5: Surface treatment: soak the tooth bar blank in a cleaning agent for 11 minutes. The cleaning agent is prepared by mixing the following raw materials: 30% sodium silicate, 20% deionized water, 10% soda ash, 15% ethanol, and 35% distilled water to achieve heat treatment and rust removal on the metal surface. The cleaning agent temperature is 65°C.

[0063] S6: ammoniating, placing the tooth bar body into a gas nitriding furnace for nitriding treatment, placing the tooth bar body into a heating furnace and heating it to 535°C, with a furnace pressure of 0.10Pa, keeping it warm for 1 hour, then closing the nitrogen valve and introducing air, using the oxygen in the air and the furnace temperature to pre-oxidize the metal mold for 8 minutes, directly transferring the tooth bar body after pre-oxidation treatment to a glow ion nitriding furnace for ion nitriding treatment, controlling the nitriding decomposition rate to be between 26%, heating in an argon atmosphere, and keeping it warm when the mold temperature reaches 600°C, keeping it warm for 24 hours, then heating it again to 590°C, controlling the nitriding decomposition rate to be between 54%, keeping it warm for 54 hours, then further heating the tooth bar body to 610°C, controlling the nitriding decomposition rate to be between 95%, and keeping it warm for 3 hours;

[0064] S7: electroplating, electroplating the nitrided tooth bar body to obtain a low-temperature high-toughness tooth bar, pouring the following three raw materials into three electroplating tanks of the electroplating box respectively, the electroplating solution placed in the first electroplating tank is composed of the following raw materials: 40 parts of deionized water, 30 parts of anti-rust film-forming agent, 7 parts of anti-rust additive, 1 part of leveling agent, 4 parts of silane coupling agent, 2 parts of thickener, the electroplating solution placed in the second electroplating tank is composed of the following raw materials: 21 parts of basic copper carbonate, 22 parts of aminosulfonic acid, 6 parts of potassium sulfate, 100 parts of distilled water, 8 parts of potassium nitrate, 0.1 parts of brightener, and the electroplating solution placed in the third electroplating tank is composed of the following raw materials: 8 parts of nickel sulfate, 4 parts of nickel sulfamate, 2 parts of reducing agent, 0.6 parts of stabilizer, 1 part of 4% organic acid, 0.03 parts of alkyl sulfonate, 0.2 parts of alkylphenol sulfonate, 0.01 parts of alkylphenol sulfate, 0.3 parts of titanium dioxide, 24 parts of deionized water. Pour the above plating solution into the solution pool of the electroplating device, and then put the tooth bar body into the electroplating box: After the electroplating device is powered on, the plating solution is heated, and the workpiece is electroplated three times. After each electroplating, it needs to be dehydrated and air-dried. The workpiece is electroplated three times. The current density, plating solution temperature and electroplating time are as follows: First time: the pole current density is 2.0A / dm 2 , the plating solution temperature is 46℃, the plating time is 5min, the second time: the polar current density is 1.4A / dm 2 , the plating solution temperature is 45℃, the plating time is 9min, the third time: the polar current density is 1.0A / dm 2 , the plating solution temperature is 40℃ and the plating time is 16min.

[0065] Embodiment 4:

[0066] See also Figure 1 , a low temperature resistant and high toughness tooth rod surface treatment method, comprising the following steps:

[0067] S1: batching, selecting materials, cutting according to given specifications and lengths, mold making: selecting pipes of corresponding lengths according to the required length of the alloy screw to be made, so as to make corresponding molds, making blanks: weighing and distributing the raw materials according to the proportions, selecting raw materials Mo: 30%, FeB: 20%, Cr: 4%, Ce: 1%, Ni: 4%, Nb: 2%, Mn: 3%, C: 1%, B2: 3%, Cr: 4%, C0: 2%, Cu: 0.4%, V0: 4%, Si: 0.3%, W0: 4%, Mn: 6%, Ta: 2%, Ai: 2%, modified phenolic resin binder: 3%, Fe: balance, wherein the modified phenolic resin binder comprises the following components in parts by weight: 100 parts of aldehyde, 0.25 parts of acid, 4 parts of methyl glucoside, 15 parts of multi-walled carbon nanotubes, 3 parts of dialdehyde, 85 parts of bismaleimide-modified phenolic resin, 10 parts of γ-aminopropyltriethoxysilane surface-modified graphene oxide, 30 parts of polyurethane resin, 2 parts of antioxidant, 2 parts of aluminum oxide particles, then put each part of the raw materials into a container, stir and mix, pour the mixture into a mold after uniform mixing, and compact it, and make the inside of the mold into a vacuum state, normalizing treatment: put the prepared blank into a calcining furnace, sinter it at a temperature of 110°C, so as to obtain a blank, and then normalize the blank in a furnace, wherein the normalizing treatment is performed 2 to 3 times, and then the screw blank after normalizing treatment is subjected to a vacuum liquid phase sintering process, the sintering temperature is 300°C, the heating rate is 14°C / min, and the holding time is 40min after reaching the predetermined temperature;

[0068] S2: Cutting the metal rod into the required length to obtain the metal rod;

[0069] S3: heat treatment, heat treating the metal rod obtained in S2 to form a rough tooth bar blank, heating the metal rod for austenitization, the austenitization temperature is 1050℃, keeping it warm for 2-3h, air cooling after taking it out of the furnace, blowing it with a fan during the air cooling process, then heating the metal rod again to 900-950℃, cooling it to 600-650℃ by furnace, and then quickly putting it into a quenching device for quenching, taking it out after the surface temperature drops to 300-350℃, and then tempering the metal rod in the quenching device, the tempering temperature is 380-450℃, the tempering time is 60-95min, keeping it warm for 1-2h, and finally cooling it to room temperature;

[0070] S4: thread rolling, processing and thread rolling the quenched tooth bar blank to obtain the tooth bar body;

[0071] S5: Surface treatment: soak the tooth bar blank in a cleaning agent for 5-15 minutes. The cleaning agent is prepared by mixing the following raw materials: 30% sodium silicate, 25% deionized water, 5% soda ash, 10% ethanol, and 30% distilled water to achieve heat treatment and rust removal on the metal surface. The cleaning agent temperature is 65°C.

[0072] S6: ammoniating, placing the tooth bar body into a gas nitriding furnace for nitriding treatment. The tooth bar body is placed into a heating furnace and heated to 500°C, with a furnace pressure of 0.10Pa, and kept warm for 1.5 hours. Then the nitrogen valve is closed and air is introduced. The metal mold is pre-oxidized for 7 minutes with the help of oxygen in the air and the furnace temperature. The tooth bar body after pre-oxidation is directly transferred to a glow ion nitriding furnace for ion nitriding treatment. The nitriding decomposition rate is controlled between 20-28%. The temperature is increased in an argon atmosphere. When the mold temperature reaches 570°C, it is kept warm for 22 hours, and then the temperature is increased to 580°C again, and the nitriding decomposition rate is controlled between 54%, and the temperature is kept warm for 56 hours. Then the tooth bar body is further heated to 600°C, and the nitriding decomposition rate is controlled at 95%, and the temperature is kept warm for 3 hours.

[0073] S7: electroplating, electroplating the nitrided tooth bar body to obtain a low-temperature high-toughness tooth bar, pouring the following three raw materials into three electroplating tanks of the electroplating box respectively, the electroplating solution placed in the first electroplating tank is composed of the following raw materials: 55 parts of deionized water, 40 parts of anti-rust film-forming agent, 5 parts of anti-rust additive, 2 parts of leveling agent, 4 parts of silane coupling agent, 2 parts of thickener, the electroplating solution placed in the second electroplating tank is composed of the following raw materials: 20 parts of basic copper carbonate, 20 parts of aminosulfonic acid, 7 parts of potassium sulfate, 120 parts of distilled water, 8 parts of potassium nitrate, 0.2 parts of brightener, and the electroplating solution placed in the third electroplating tank is composed of the following raw materials: 8 parts of nickel sulfate, 4 parts of nickel sulfamate, 2 parts of reducing agent, 0.6 parts of stabilizer, 2 parts of 4% organic acid, 0.02 parts of alkyl sulfonate, 0.02 parts of alkylphenol sulfonate, 0.02 parts of alkylphenol sulfate, 0.4 parts of titanium dioxide, 30 parts of deionized water, pour the above plating solution into the solution pool of the electroplating device, and then put the tooth bar body into the electroplating box: after the electroplating device is powered on, the plating solution is heated, and the workpiece is electroplated three times. After each electroplating, it needs to be dehydrated and air-dried. The workpiece is electroplated three times. The current density, plating solution temperature and electroplating time are as follows: the first time: the pole current density is 2.0A / dm 2 , the plating solution temperature is 50℃, the plating time is 5min, the second time: the polar current density is 1.5A / dm 2 , the plating solution temperature is 50℃, the plating time is 9min, the third time: the polar current density is 1.0A / dm 2 , the plating solution temperature is 30-50℃, and the plating time is 10-20min.

Claims

1. A method for treating the surface of a low-temperature-resistant and high-toughness tooth rod, characterized in that: The steps include: S1: batching, selecting materials and cutting them according to given specifications and lengths; S2: Cutting the metal rod into the required length to obtain the metal rod; S3: heat treatment, heat treating the metal rod obtained in S2 to form a rough tooth bar blank; S4: thread rolling, processing and thread rolling the quenched tooth bar blank to obtain the tooth bar body; S5: surface treatment, surface treatment of the rough tooth blank; S6: ammoniation, placing the tooth rod body into a gas nitriding furnace for nitriding treatment; S7: electroplating, electroplating the nitrided tooth bar body to obtain a low-temperature high-toughness tooth bar.

2. A method for surface treatment of a low temperature resistant and high toughness tooth rod according to claim 1, characterized in that: The tooth rod material is prepared according to the following raw material powder mass fraction ratio: Mo: 17-55%, FeB: 10-40%, Cr: 3-10%, Ce: 0.2-2%, Ni: 2-10%, Nb: 1-4%, Mn: 1-7%, C: 0.1-1%, B2: 2-7%, Cr: 4-10%, C0: 1-3%, Cu: 0.1-0.7%, V0: 4-6%, Si: 0.2-0.4%, W0: 4-6%, Mn: 5-15%, Ta: 1-4%, Ai: 1-4%, modified phenolic resin adhesive: 2-7%, Fe: balance.

3. A method for surface treatment of a low temperature resistant and high toughness tooth rod according to claim 1, characterized in that: The tooth rod material is produced in the following manner: S1. Mould making: according to the required length of the alloy screw to be made, a pipe of corresponding length is selected to make a corresponding mould; S2. Blank making: the raw materials are weighed and distributed according to the ratio, and then each portion of the raw materials is put into a container, stirred and mixed, and after uniform mixing, the mixture is poured into the mould, compacted, and the inside of the mould is made into a vacuum state; S3. Normalising: the prepared blank is put into a calcining furnace for sintering, wherein the temperature is 105-110°C, thereby obtaining a blank, and then the blank is normalised in the furnace, wherein the normalising is performed 2 to 3 times; S5: the screw blank after normalising is then subjected to a vacuum liquid phase sintering process, the sintering temperature is 260-400°C, the heating rate is 10-20°C / min, and the holding time is 30-80min after reaching the predetermined temperature.

4. A method for surface treatment of a low temperature resistant and high toughness tooth rod according to claim 2, characterized in that: The modified phenolic resin adhesive comprises the following components in parts by weight: 100-200 parts of aldehyde, 0.1-0.25 parts of acid, 2-4 parts of methyl glucoside, 15-22 parts of multi-walled carbon nanotubes, 1-3 parts of dialdehyde, 75-85 parts of bismaleimide-modified phenolic resin, 10-18 parts of gamma-aminopropyltriethoxysilane surface-modified graphene oxide, 20-30 parts of polyurethane resin, 1-2 parts of antioxidant and 2-5 parts of aluminum oxide particles.

5. The surface treatment method of a low temperature resistant and high toughness tooth rod according to claim 1, characterized in that: The S2 metal rod is heated up for austenitization at a temperature of 950-1050°C, kept at this temperature for 2-3 hours, and air-cooled after being taken out of the furnace. During the air-cooling process, the metal rod is blown by a fan, and then the metal rod is heated to 900-950°C again, furnace-cooled to 600-650°C, and then quickly placed in a quenching device for quenching. When the surface temperature drops to 300-350°C, it is taken out and then tempered in the quenching device at a tempering temperature of 380-450°C, a tempering time of 60-95min, kept at this temperature for 1-2 hours, and finally cooled to room temperature.

6. A method for surface treatment of a low temperature resistant and high toughness tooth rod according to claim 1, characterized in that: The method for surface treatment of the rough tooth bar blank in S5 is soaking in a cleaning agent for 5-15 minutes. The cleaning agent is prepared by mixing the following raw materials: 20-30% sodium silicate, 20-30% deionized water, 5-10% soda ash, 10-20% ethanol, and 30-40% distilled water to achieve metal surface heat treatment and rust removal. The cleaning agent temperature is 50-85°C.

7. The surface treatment method of a low temperature resistant and high toughness tooth rod according to claim 1, characterized in that: The steps of nitriding treatment described in S6 are: first, the tooth bar body is placed in a heating furnace and heated to 500-535°C, the furnace pressure is 0.02-0.10Pa, and the temperature is kept for 1-1.5h, then the nitrogen valve is closed, and air is introduced, and the metal mold is pre-oxidized for 5-10min with the help of oxygen in the air and the furnace temperature, and the tooth bar body after pre-oxidation is directly transferred to a glow ion nitriding furnace for ion nitriding treatment, and the nitriding decomposition rate is controlled between 20-28%, and the temperature is increased in an argon atmosphere. When the mold temperature reaches 550-670°C, it is kept warm for 22-26h, and then the temperature is increased again to 570-590°C, and the nitriding decomposition rate is controlled between 50-55%, and the temperature is kept for 53-56h. Then, the tooth bar body is further heated to 590-610°C, and the nitriding decomposition rate is controlled between 90-95%, and the temperature is kept for 2-4h.

8. The surface treatment method of a low temperature resistant and high toughness tooth rod according to claim 1, characterized in that: The electroplating process described in S8 comprises the following steps: S1, raw material preparation: pour the following three raw materials into three electroplating tanks of the electroplating box respectively; S2, putting the tooth rod body into the electroplating box: after the electroplating device is powered on, the electroplating solution is heated, and the workpiece is electroplated three times. After each electroplating, it needs to be dehydrated and air-dried.

9. A method for surface treatment of a low temperature resistant and high toughness tooth rod according to claim 8, characterized in that: The electroplating solution placed in the first electroplating tank is composed of the following raw materials: 15-70 parts of deionized water, 10-50 parts of anti-rust film-forming agent, 3-12 parts of anti-rust additive, 0.5-2 parts of leveling agent, 1.5-5 parts of silane coupling agent, and 1-2 parts of thickener; The electroplating solution placed in the second electroplating tank is composed of the following raw materials: 18-22 parts of basic copper carbonate, 12-25 parts of aminosulfonic acid, 5-10 parts of potassium sulfate, 50-150 parts of distilled water, 5-10 parts of potassium nitrate, and 0.1-0.2 parts of brightener; The electroplating solution placed in the third electroplating tank is composed of the following raw materials: 4-15 parts of nickel sulfate, 2-5 parts of nickel sulfamate, 1-3 parts of reducing agent, 0.3-0.6 parts of stabilizer, 1-3 parts of 2-5% organic acid, 0.01-0.03 parts of alkyl sulfonate, 0.01-0.03 parts of alkylphenol sulfonate, 0.01-0.03 parts of alkylphenol sulfate, 0.2-0.5 parts of titanium dioxide, and 20-30 parts of deionized water.

10. A method for surface treatment of a low temperature resistant and high toughness tooth rod according to claim 9, characterized in that: The workpiece undergoes three electroplating cycles with the following current density, plating solution temperature, and plating time: First time: the current density is 1.0-2.0A / dm 2 , the plating solution temperature is 45-50℃, and the plating time is 4-6min; Second time: the current density is 1.4-1.8A / dm 2 , the plating solution temperature is 40-50℃, and the plating time is 7-12min; The third time: the current density is 0.8-1.0A / dm 2 , the plating solution temperature is 30-50℃, and the plating time is 10-20min.

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