A carbonitriding clamp heat treatment process

Abstract

The application discloses a kind of carbonitriding clamping piece heat treatment process method, specifically relates to heat treatment process technical field, its specific process method is in turn: cleaning, drying, carbonitriding, quenching, secondary cleaning, tempering and air cooling;The cleaning mode of air foaming flushing and high-pressure spray cleaning is used in the application, to ensure the thoroughness and uniformity of the clamping piece cleaning;Centrifugal circulating fan is used to control atmosphere circulation and heat transfer during carbonitriding process, to ensure the uniformity of penetration layer depth and the uniformity of furnace temperature, secondary cleaning process is used to remove the oil stains on the surface of the clamping piece caused by carbonitriding, to ensure the tempering quality;Mobile trolley automation control and linear turnover mode are used in the overall process flow, reducing the product loading and unloading frequency, improving the turnover efficiency;Controllable atmosphere sealed box type multi-purpose furnace is monitored by furnace body, to control the flow of propane, ammonia and other gas flow meters, so that the flow is within the set range, to control the carbon potential reasonably.

Description

Technical Field

[0001] The present invention relates to the technical field of heat treatment technology, and more particularly to a heat treatment process method for carbonitriding clips. Background Art

[0002] The clip is a key component of the clip-type anchor in the prestressed anchoring system. It achieves the purpose of anchoring by biting the steel strand. Due to the high hardness of the steel strand and the certain elastic deformation of the clip during the biting anchoring process, the entire use process has high requirements on the surface hardness, comprehensive toughness, fatigue strength and other aspects of the clip. Alloy structural steel can adopt various heat treatment strengthening processes such as tempering, carburizing and quenching according to different uses. However, the carbonitriding process in the existing heat treatment has the problem of uneven or low furnace temperature, resulting in uneven or shallow diffusion layer, which is not conducive to the heat treatment effect.

[0003] Therefore, the present invention proposes a carbonitriding clip heat treatment process method, which is aimed at the clip-type anchor in the prestressed anchoring system to ensure the uniformity of the penetration layer depth and the uniformity of the furnace temperature; and provides a heat treatment process suitable for strengthening the surface hardness, core toughness and comprehensive mechanical properties of the clip. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a carbonitriding clip heat treatment process method to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: a carbonitriding sandwich heat treatment process, characterized in that: the specific process is as follows:

[0006] Step 1: Cleaning: Move the clip to be cleaned to the front room of the cleaning machine and clean it in the cleaning solution;

[0007] Step 2: Drying: After completing step 1, move the product to be cleaned into the back room of the cleaning machine for drying; when the control system prompts to move out, move the clip out;

[0008] Step 3: Carbonitriding: After completing step 2, the dried product is moved to the front chamber of a controlled atmosphere sealed box-type multi-purpose furnace for ventilation, and then moved into the back chamber of a controlled atmosphere sealed box-type multi-purpose furnace to complete the carbonitriding process;

[0009] Step 4: Quenching: After completing step 3, quench the product using special quenching oil;

[0010] Step 5: Secondary cleaning: After completing step 4, transfer the treated clips to the cleaning machine for cleaning and degreasing;

[0011] Step 6: Tempering: After completing step 5, move the product into the tempering furnace to complete the tempering;

[0012] Step 7: Air Cooling: After completing step 6, remove the clips from the tempering furnace and air cool them before moving them to the finishing station.

[0013] Furthermore, in step one, the cleaning method adopts air foaming flushing and high-pressure spray cleaning.

[0014] Furthermore, in the steps 1 and 5, the cleaning temperature of the cleaning process is 70-90° C., and the time is 10 to 30 minutes.

[0015] Furthermore, in the step 2, the drying temperature is 125±10° C. and the drying time is 10 to 30 minutes.

[0016] Furthermore, the carbonitriding process in step three is as follows: heating - temperature equalization - strong carbonitriding - diffusion - cooling - temperature equalization, and the temperature of the temperature equalization, strong carbonitriding and diffusion is controlled at 860-880°C, and the time is 20 minutes, 170 minutes and 40 minutes respectively.

[0017] Furthermore, during the carbonitriding process in step three, a nitrogen atmosphere protection method is adopted.

[0018] Furthermore, during the carbonitriding process in step three, a centrifugal circulation fan is used to control atmosphere circulation and heat transfer.

[0019] Furthermore, during the carbonitriding process in step three, a gas flow meter is provided inside the controlled atmosphere sealed box-type multi-purpose furnace.

[0020] Furthermore, in step 4, the quenching oil temperature is controlled at 85-90°C.

[0021] Furthermore, in step six, the tempering process temperature is controlled to be 140-170° C., and the time is controlled to be 140-160 minutes.

[0022] Technical effects and advantages of the present invention:

[0023] 1. In the prior art, the carbonitriding process in the heat treatment industry has problems such as uneven or too shallow infiltration layers due to uneven or low furnace temperatures. The present invention uses a centrifugal circulating fan to control atmosphere circulation and heat transfer during the carbonitriding process of clip-type anchors in prestressed anchoring systems, ensuring uniformity in the depth of the infiltration layer and uniformity in the furnace temperature. Since the energy consumption of heat treatment is related to temperature, the energy consumption of the carburizing process is relatively high. Moreover, due to the high heat treatment temperature, the deformation of the product after quenching is relatively large, which cannot meet the precision requirements of the clip products. Therefore, the quenching oil temperature is controlled at 85-90°C to ensure the stability of the quenching quality.

[0024] 2. Compared with the existing technology, heat-treated products are prone to poor cleaning effects due to product accumulation during the cleaning process. Air foaming and high-pressure spray cleaning methods are used to ensure the thoroughness and uniformity of the clip cleaning. A secondary cleaning process is used to remove oil stains on the clip surface caused by carbonitriding, ensure the tempering quality, and ensure that the wear resistance and comprehensive mechanical properties of the processed products can meet the clip anchoring performance requirements.

[0025] 3. The overall process flow adopts automatic control of mobile material carts and linear turnover mode, which reduces the number of product loading and unloading times and improves turnover efficiency; the controlled atmosphere sealed box-type multi-purpose furnace monitors the furnace body and controls the gas flow meters such as propane and ammonia to keep the flow within the set range in order to reasonably control the carbon potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] As attached Figure 1 A carbonitriding heat treatment process for a clip is shown, and the process is as follows:

[0029] Step 1: Cleaning: Place the mobile material cart at the cleaning station and pull the clip to be cleaned onto the mobile material cart; confirm that the guide rail of the cart is aligned with the guide rail in front of the cleaning machine door, move the clip to be cleaned to the front chamber of the cleaning machine, and use air foaming and high-pressure spray cleaning in the cleaning liquid to ensure the thoroughness and uniformity of the clip cleaning; the cleaning temperature is 70-90℃ and the time is 10-30 minutes;

[0030] Step 2: Drying: After the front chamber of the cleaning machine is cleaned, the control system will prompt to move in, and then move the cleaned products into the back chamber of the cleaning machine for drying; the drying temperature is 125±10℃, and the drying time is 10-30 minutes. When the control system prompts to move out, move the clips out;

[0031] Step 3: Carbonitriding: Move the dried product trolley to the front of the controlled atmosphere sealed box-type multi-purpose furnace, and make sure that the trolley guide rail is aligned with the guide rail in front of the furnace door; move the product into the front chamber of the controlled atmosphere sealed box-type multi-purpose furnace for ventilation, and then move it into the back chamber of the controlled atmosphere sealed box-type multi-purpose furnace to complete carbonitriding; the carbonitriding process is as follows: heating-averaging-intensive permeation-diffusion-cooling-averaging, wherein the temperature of averaging, intense permeation, and diffusion is controlled at 860-880℃, and the time is 20 minutes, 170 minutes, and 40 minutes respectively; nitrogen is used for atmosphere protection during the carbonitriding process, and a centrifugal circulation fan is used to control the atmosphere circulation and heat transfer to ensure the uniformity of the depth of the permeation layer and the uniformity of the temperature in the furnace, so as to improve the stability of product quality; the gas flow meter installed inside the controlled atmosphere sealed box-type multi-purpose furnace is used to focus on controlling the furnace temperature, propane and ammonia flow rates, etc., so that the flow rates are within the set range, so as to reasonably control the carbon potential;

[0032] Step 4: Quenching: Quenching is performed in a controlled atmosphere sealed box-type multi-purpose furnace using special quenching oil to ensure that the product does not undergo obvious deformation or oxidation during the quenching process; the quenching oil temperature is controlled at 85-90°C;

[0033] Step 5: Secondary cleaning: Transfer the carbon quenched clips to the cleaning machine for cleaning and degreasing. The temperature and time control are the same as the cleaning process in step 1. The cleaning temperature is 70-90℃ and the time is 10-30 minutes.

[0034] Step 6: Tempering: Move the mobile trolley to the front of the tempering furnace, confirm that the trolley guide rails are aligned with the guide rails in front of the tempering furnace door, move the product into the tempering furnace, complete the tempering, then move the clips out and move them to the finishing table; the tempering process is controlled at a temperature of 140-170°C and a time of 140-160 minutes;

[0035] Step 7: Air cooling: After the clip is tempered, remove it from the tempering furnace and air cool it to further improve the anchoring performance of the clip.

[0036] The heat treatment process involved in the present invention is a heat treatment process suitable for strengthening the surface hardness, core toughness and comprehensive mechanical properties of the clip, so as to enhance the comprehensive mechanical properties of the clip, such as wear resistance, bite anchoring performance, elasticity, etc., and improve the service life of the clip.

[0037] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0038] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A carbonitriding interlayer heat treatment process, characterized by: The specific process is as follows: Step 1: Cleaning: Move the clip to be cleaned to the front room of the cleaning machine and clean it in the cleaning solution; Step 2: Drying: After completing step 1, move the product to be cleaned into the back room of the cleaning machine for drying; when the control system prompts to move out, move the clip out; Step 3: Carbonitriding: After completing step 2, the dried product is moved to the front chamber of a controlled atmosphere sealed box-type multi-purpose furnace for ventilation. A centrifugal circulation fan is used to control atmosphere circulation and heat transfer during the carbonitriding process. The controlled atmosphere sealed box-type multi-purpose furnace is equipped with a gas flow meter. The product is then moved to the back chamber of the controlled atmosphere sealed box-type multi-purpose furnace to complete the carbonitriding process. The carbonitriding process is as follows: heating - equalizing temperature - strong carbonitriding - diffusion - cooling - equalizing temperature, and the temperature of equalizing temperature, strong carbonitriding and diffusion is controlled at 860-880°C, and the time is 20 minutes, 170 minutes and 40 minutes respectively; Step 4: Quenching: After completing step 3, quench the product with special quenching oil, and control the quenching oil temperature at 85-90℃; Step 5: Secondary cleaning: After completing step 4, transfer the treated clips to the cleaning machine for cleaning and degreasing; Step 6: Tempering: After completing step 5, move the product into the tempering furnace to complete the tempering; Step 7: Air Cooling: After completing step 6, remove the clips from the tempering furnace and air cool them before moving them to the finishing station.

2. The carbonitriding heat treatment process of claim 1, wherein: In the step 1, the cleaning method adopts air foaming and high-pressure spray cleaning.

3. The carbonitriding heat treatment process of claim 1, wherein: In the steps 1 and 5, the cleaning temperature of the cleaning process is 70-90° C. and the time is 10-30 minutes.

4. The carbonitriding heat treatment process of claim 1, wherein: In the step 2, the drying temperature is 125±10° C. and the drying time is 10 to 30 minutes.

5. The carbonitriding heat treatment process of claim 1, wherein: During the carbonitriding process in step three, a nitrogen atmosphere protection method is adopted.

6. The carbonitriding heat treatment process of claim 1, wherein: In step six, the tempering process is controlled at a temperature of 140-170° C. and a time of 140-160 minutes.

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