Steel workpiece pressurization blackening treatment method and system

Abstract

The invention relates to a pressurized blackening treatment method and system for a steel workpiece. The method comprises the steps that the steel workpiece is placed in a pressurized container, blackening liquid is added into the pressurized container, the blackening liquid is heated, the pressurized container is pressurized, and blackening treatment is conducted on the steel workpiece; determining environment conditions of blackening treatment corresponding to the steel workpiece, wherein the environment conditions comprise blackening liquid temperature, initial heating power, pressure intensity in a blackening treatment container when the workpiece is put into the blackening treatment container and blackening treatment time; the temperature of the blackening liquid and the pressure in the blackening treatment container are monitored in real time, and the heating power is adjusted; the system is used for executing the method. The blackening treatment process is always in a closed environment, the evaporation amount of blackening liquid is small, harmful gas generated in the blackening liquid heating process cannot escape, and energy consumption and environmental pollution are reduced; due to the fact that the evaporation amount of the blackening liquid is small, and the temperature change amplitude of the blackening liquid is small, the blackening treatment process is stable, and the blackening treatment effect of the workpiece is more stable.

Description

Technical Field

[0001] The present disclosure relates to the technical field of steel workpiece processing, and in particular to a method and system for pressurized blackening processing of steel workpieces. Background Art

[0002] In order to improve the rust resistance of steel parts, a strong oxidant is used to oxidize the surface of the steel parts into a dense and smooth ferroferric oxide. This thin layer of ferroferric oxide can effectively protect the inside of the steel parts from oxidation. This treatment process is called blackening process.

[0003] In the prior art, the blackening process includes pretreatment, blackening treatment and post-treatment, wherein the blackening treatment is usually a chemical reaction in an alkaline or acidic solution under heating or room temperature. Specifically, the workpiece to be blackened is immersed in the solution and reacted under heating or room temperature conditions.

[0004] Since an oxide film needs to be formed on the surface of the workpiece, the blackening liquid usually includes an oxidant. Specifically, sodium nitrite is usually used as the oxidant in the blackening liquid. During the heating process, the solute in the blackening liquid is also more likely to decompose, causing certain pollution. In addition, for various types of steel, the corresponding blackening treatment temperature and time are also different. The various ion concentrations in the blackening liquid cannot be obtained in real time, so that during the reaction process, the blackening liquid cannot be adjusted in real time according to the ion concentration, and the success rate of the blackening treatment is low.

[0005] Since the conventional blackening treatment container is an open container, when the conventional blackening treatment container is heated, the blackening liquid is easy to evaporate, the liquid level of the blackening liquid drops too quickly, and the blackening liquid evaporates and takes away a lot of heat, resulting in the need for frequent heating and consumption of a lot of energy; at the same time, the blackening liquid is easy to produce harmful gases when heated, threatening personal safety and causing environmental pollution;

[0006] In addition, if the container is replaced with a closed container, heating the liquid and increasing the pressure inside the container will help speed up the blackening process. However, there are currently no related applications. Therefore, how to control the blackening process through the linkage of pressure and temperature is a difficult problem in the current blackening process. Summary of the invention

[0007] In order to solve the problems existing in the above-mentioned prior art, the purpose of the present disclosure is to provide a method and system for pressurized blackening treatment of steel workpieces, so as to solve the technical problem that the prior art cannot well control the blackening treatment.

[0008] The present disclosure discloses a method for pressurized blackening of a steel workpiece, comprising: placing the steel workpiece in a pressurized container, adding a blackening liquid into the pressurized container, heating the blackening liquid and pressurizing the pressurized container to perform pressurized blackening on the steel workpiece;

[0009] During the pressurized blackening treatment process, a control operation is performed on the pressurized blackening treatment, and the control operation includes:

[0010] Acquire the size information of the steel workpiece, the size information of the blackening treatment container, and the type of steel used for the steel workpiece, and determine the environmental conditions for the blackening treatment corresponding to the steel workpiece, wherein the environmental conditions include the temperature of the blackening liquid, the initial heating power, the pressure in the blackening treatment container when the workpiece is placed in the blackening treatment container, and the blackening treatment time;

[0011] The temperature of the blackening liquid in the blackening treatment container and the pressure in the blackening treatment container are monitored in real time to adjust the heating power.

[0012] Preferably, the determination of the environmental conditions corresponding to the pressurized blackening treatment of the steel workpiece includes:

[0013] Obtaining the type of steel, and determining the temperature of the blackening liquid and the blackening treatment time when the workpiece is placed in the blackening treatment container according to the type of steel used for the steel workpiece;

[0014] Determine the volume of the blackening liquid according to the size information of the steel workpiece and the size information of the blackening treatment container;

[0015] The types of steel used in the steel workpiece include: structural steel, cast iron, low carbon steel, high carbon steel, medium carbon steel, chrome silicon steel, high alloy steel and high speed steel.

[0016] Preferably, the real-time monitoring of the temperature of the blackening liquid in the blackening treatment container and the pressure in the blackening treatment container and adjusting the heating power comprises:

[0017] Monitor the temperature of the blackening liquid in real time by using a temperature sensor;

[0018] A pressure threshold is preset, and when the pressure inside the blackening treatment container is monitored to be higher than the pressure threshold, a decompression operation is performed;

[0019] When the pressure inside the blackening treatment container is monitored to be lower than the pressure threshold, the heating power is adjusted through a PID control algorithm according to the temperature of the blackening liquid obtained through real-time monitoring.

[0020] The present disclosure also provides a system for pressurized blackening treatment of steel workpieces, which is used to execute the pressurized blackening treatment method of steel workpieces as described above.

[0021] The advantages of the pressurized blackening treatment method and system for steel workpieces disclosed in the present invention are:

[0022] Since the blackening process is placed in a closed container, the blackening process is always in a closed environment. When the blackening process is heated in the closed container and the saturated vapor pressure is reached, the evaporation and liquefaction in the closed container are in dynamic equilibrium. At this time, the internal environment of the blackening process container is in a dynamic equilibrium state. The gas generated in the blackening process will not escape from the blackening process container during the blackening process. After the blackening process is completed, the gas will be re-liquefied into blackening liquid when the blackening process container is cooled, thereby reducing the escape of harmful gases, avoiding threats to personal safety, and reducing environmental pollution.

[0023] Since the blackening treatment container is a closed container, the evaporated blackening liquid will not escape from the blackening treatment container when the internal pressure of the blackening treatment container is lower than the opening pressure of the safety valve. Therefore, the evaporation amount of the blackening liquid is reduced. The reduced evaporation amount of the blackening liquid makes the blackening liquid level basically unchanged, that is, there is no need to frequently replenish the blackening liquid. Therefore, the heating power is relatively stable and the energy loss is low.

[0024] At the same time, since there is no need to frequently replenish the blackening liquid, the temperature variation of the blackening liquid is small, so the blackening process is relatively stable, making the blackening effect of the workpiece more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of a method for pressurized blackening of a steel workpiece disclosed in the present invention. DETAILED DESCRIPTION

[0026] like Figure 1 As shown, a method for pressurizing and blackening a steel workpiece disclosed in the present invention comprises:

[0027] Placing a steel workpiece in a pressurized container, adding a blackening liquid into the pressurized container, heating the blackening liquid and pressurizing the pressurized container to perform a pressurized blackening treatment on the steel workpiece;

[0028] During the pressurized blackening treatment process, a control operation is performed on the pressurized blackening treatment, and the control operation includes:

[0029] Acquire the size information of the steel workpiece, the size information of the blackening treatment container, and the type of steel used in the steel workpiece, and determine the environmental conditions for the pressurized blackening treatment corresponding to the steel workpiece, wherein the environmental conditions include the temperature of the blackening liquid, the initial heating power, the pressure in the blackening treatment container when the workpiece is placed in the blackening treatment container, and the blackening treatment time;

[0030] The temperature of the blackening liquid in the blackening treatment container and the pressure in the blackening treatment container are monitored in real time to adjust the heating power.

[0031] Furthermore, determining the environmental conditions for the pressurized blackening treatment corresponding to the steel workpiece includes:

[0032] Obtaining the type of steel, and determining the temperature of the blackening liquid and the blackening treatment time when the workpiece is placed in the blackening treatment container according to the type of steel used for the steel workpiece;

[0033] Determine the volume of the blackening liquid according to the size information of the steel workpiece and the size information of the blackening treatment container;

[0034] The types of steel used in the steel workpiece include: structural steel, cast iron, low carbon steel, high carbon steel, medium carbon steel, chrome silicon steel, high alloy steel and high speed steel.

[0035] Further, real-time monitoring of the temperature of the blackening liquid in the blackening treatment container and the pressure in the blackening treatment container and adjusting the heating power include:

[0036] Monitor the temperature of the blackening liquid in real time by using a temperature sensor;

[0037] A pressure threshold is preset, and when the pressure inside the blackening treatment container is monitored to be higher than the pressure threshold, a decompression operation is performed;

[0038] When the pressure inside the blackening treatment container is monitored to be lower than the pressure threshold, the heating power is adjusted through a PID control algorithm according to the temperature of the blackening liquid obtained through real-time monitoring.

[0039] For example, taking the blackening treatment of low carbon steel as an example, the temperature of the blackening liquid is 140°C. The temperature in the blackening treatment container is obtained in real time through a temperature sensor. The heating power is adjusted through a PID control algorithm to maintain the temperature of the blackening liquid at 140°C. The preset pressure threshold is 5.0 bar (i.e. 0.50 MPa), that is, the opening pressure of the safety valve of the blackening treatment container is 5.0 bar. When it is monitored that the pressure inside the pressurized container is greater than 5.0 bar, the pressure reducing valve of the pressurized container is opened; if the pressure in the blackening treatment container is less than 5.0 bar, the temperature of the blackening liquid in the blackening treatment container is continuously monitored, and the heating power is adjusted in real time through the PID control algorithm to ensure that the temperature of the blackening liquid is maintained at 140°C, so as to ensure the stability of the blackening treatment.

[0040] Since the heating is carried out in a closed environment, the pressure will increase with the rise of temperature during the heating process. When the blackening treatment temperature is reached, the PID control algorithm adjusts the heating power to keep the temperature of the blackening liquid at 140°C. When the saturated vapor pressure is reached, the internal environment of the blackening treatment container is in a dynamic equilibrium state. The gas generated during the blackening treatment process will not escape from the blackening treatment container during the blackening treatment process. After the blackening treatment is completed, the gas will re-liquefy into blackening liquid when the blackening treatment container is cooled, thereby reducing the escape of harmful gases, avoiding threats to personal safety, and reducing environmental pollution.

[0041] Since the blackening treatment container is a closed container, the evaporated blackening liquid will not escape from the blackening treatment container when the internal pressure of the blackening treatment container is lower than the opening pressure of the safety valve. Therefore, the evaporation amount of the blackening liquid is reduced. The reduced evaporation amount of the blackening liquid makes the blackening liquid level basically unchanged, that is, there is no need to frequently replenish the blackening liquid. Therefore, the heating power is relatively stable and the energy loss is low.

[0042] At the same time, since there is no need to frequently replenish the blackening liquid, the temperature variation of the blackening liquid is small, so the blackening process is relatively stable, making the blackening effect of the workpiece more stable.

[0043] Furthermore, the present invention also discloses a steel workpiece pressurized blackening treatment system for executing the above-mentioned steel workpiece pressurized blackening treatment method.

[0044] In the description of the present disclosure, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present disclosure.

[0045] For those skilled in the art, various other corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all of these changes and deformations should fall within the protection scope of the claims of the present disclosure.

Claims

1. A method for pressurizing and blackening a steel workpiece, characterized in that: include: Placing a steel workpiece in a pressurized container, adding a blackening liquid into the pressurized container, heating the blackening liquid and pressurizing the pressurized container to perform a pressurized blackening treatment on the steel workpiece; During the pressurized blackening treatment process, a control operation is performed on the pressurized blackening treatment, and the control operation includes: Acquire the size information of the steel workpiece, the size information of the blackening treatment container, and the type of steel used in the steel workpiece, and determine the environmental conditions for the pressurized blackening treatment corresponding to the steel workpiece, wherein the environmental conditions include the temperature of the blackening liquid, the initial heating power, the pressure in the blackening treatment container when the workpiece is placed in the blackening treatment container, and the blackening treatment time; The temperature of the blackening liquid in the blackening treatment container and the pressure in the blackening treatment container are monitored in real time to adjust the heating power.

2. The method for pressurizing and blackening a steel workpiece according to claim 1, characterized in that: The determination of the environmental conditions corresponding to the pressurized blackening treatment of the steel workpiece includes: Obtaining the type of steel, and determining the temperature of the blackening liquid and the blackening treatment time when the workpiece is placed in the blackening treatment container according to the type of steel used for the steel workpiece; Determine the volume of the blackening liquid according to the size information of the steel workpiece and the size information of the blackening treatment container; The types of steel used in the steel workpiece include: structural steel, cast iron, low carbon steel, high carbon steel, medium carbon steel, chrome silicon steel, high alloy steel and high speed steel.

3. The method for pressurizing and blackening a steel workpiece according to claim 2, characterized in that: The real-time monitoring of the temperature of the blackening liquid inside the blackening treatment container and the pressure inside the blackening treatment container and adjusting the heating power includes: Monitor the temperature of the blackening liquid in real time by using a temperature sensor; A pressure threshold is preset, and when the pressure inside the blackening treatment container is monitored to be higher than the pressure threshold, a decompression operation is performed; When the pressure inside the blackening treatment container is monitored to be lower than the pressure threshold, the heating power is adjusted through a PID control algorithm according to the temperature of the blackening liquid obtained through real-time monitoring.

4. A system for pressurized blackening of steel workpieces, characterized in that: The steel workpiece pressurized blackening treatment system is used to execute the steel workpiece pressurized blackening treatment method as claimed in any one of claims 1 to 3.

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