A method for judging the slow cooling state of continuous casting billets

Abstract

The present invention discloses a method for judging the slow cooling state of continuous casting billets, which specifically includes the following steps: S1, feeding the T5 heat-resistant steel continuous casting billet into the first slow cooling furnace, and arranging three temperature induction image acquisition devices in the first slow cooling furnace; S2, gradually heating the T5 heat-resistant steel continuous casting billet to 790 ± 5 °C, and then feeding it into the second slow cooling furnace, and arranging seven temperature induction image acquisition devices in the second slow cooling furnace; arranging a first image acquisition device at the end of the eighth section of the second slow cooling furnace for acquiring the surface crack information of the continuous casting billet; obtaining the thermal imaging information of the continuous casting billet in each stage through the temperature induction image acquisition devices arranged in each slow cooling stage, judging the slow cooling state of the continuous casting billet, solving the problems of low efficiency and large error existing in the need for multiple manual measurements of the temperature in the slow cooling pit, and training the thermal imaging information of the continuous casting billet and the surface crack information of the continuous casting billet through a training model to improve the recognition accuracy of the slow cooling state of the continuous casting billet and conduct transportation control.

Description

Technical Field

[0001] The present invention relates to the field of metallurgical technology, and particularly relates to a method for judging the slow cooling state of continuous casting billets. Background Art

[0002] Some domestic steel production enterprises face a series of problems such as high production costs and low service performance when heat-treating continuous casting billets by using traditional heat treatment furnaces. Therefore, the slow cooling pit technology has gradually become a hot topic in the iron and steel industry, enabling the slow cooling of the produced continuous casting billets, so as to increase the phenomenon of adaptation generated by the device during the cooling process. However, the existing slow cooling pits on the market cannot meet the production requirements when controlling the temperature of continuous casting billets. During the experimental process of controlling and adjusting the slow cooling temperature, it is necessary to measure the temperature in the slow cooling pit multiple times, and then judge the slow cooling state of the continuous casting billet according to the measured data values. At present, the temperature measurement in the slow cooling pit and the judgment of the continuous casting billet state are both carried out manually, with low efficiency and large errors. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for judging the slow cooling state of continuous casting billets in view of the deficiencies of the prior art.

[0004] The technical solution for the present invention to solve the above problems is as follows: A method for judging the slow cooling state of continuous casting billets specifically includes the following steps:

[0005] S1. Feed the T5 heat-resistant steel continuous casting billet into the first slow cooling furnace, and the first slow cooling furnace includes four sections; when the continuous casting billet passes through the first slow cooling furnace, it is heated to a set temperature in the first section and kept warm for 1 - 2 hours, then transported to the second section for slow cooling to the set temperature, then transported to the third section for slow cooling to the set temperature, and finally transported to the fourth section for cooling to room temperature. Three temperature induction image acquisition devices are arranged in the first slow cooling furnace, namely the first temperature induction image acquisition device, the second temperature induction image acquisition device, and the third temperature induction image acquisition device. Among them, the first temperature induction image acquisition device is arranged at the end of the first section of the first slow cooling furnace, the second temperature induction image acquisition device is arranged at the end of the second section of the first slow cooling furnace, and the third temperature induction image acquisition device is arranged at the end of the third section of the first slow cooling furnace; the first temperature induction image acquisition device obtains the first continuous casting billet thermal imaging information, the second temperature induction image acquisition device obtains the second continuous casting billet thermal imaging information, and the third temperature induction image acquisition device obtains the third continuous casting billet thermal imaging information;

[0006] S2. Gradually heat the T5 heat-resistant steel continuous casting billet to 790 ± 5 °C, and then send it into the second slow cooling furnace. The second slow cooling furnace consists of eight sections. After the continuous casting billet is kept warm in the first section for 4 - 5 hours, it is successively transported to other sections for slow cooling to the set temperature, and finally cooled to room temperature in the eighth section. Seven temperature induction image acquisition devices are set in the second slow cooling furnace, namely the fourth temperature induction image acquisition device, the fifth temperature induction image acquisition device, the sixth temperature induction image acquisition device, the seventh temperature induction image acquisition device, the eighth temperature induction image acquisition device, the ninth temperature induction image acquisition device, and the tenth temperature induction image acquisition device. The fourth temperature induction image acquisition device is set at the end of the first section of the second slow cooling furnace, the fifth temperature induction image acquisition device is set at the end of the second section of the second slow cooling furnace, the sixth temperature induction image acquisition device is set at the end of the third section of the second slow cooling furnace, the seventh temperature induction image acquisition device is set at the end of the fourth section of the second slow cooling furnace, the eighth temperature induction image acquisition device is set at the end of the fifth section of the second slow cooling furnace, the ninth temperature induction image acquisition device is set at the end of the sixth section of the second slow cooling furnace, and the tenth temperature induction image acquisition device is set at the end of the seventh section of the second slow cooling furnace. The fourth temperature induction image acquisition device obtains the thermal imaging information of the fourth continuous casting billet, the fifth temperature induction image acquisition device obtains the thermal imaging information of the fifth continuous casting billet, the sixth temperature induction image acquisition device obtains the thermal imaging information of the sixth continuous casting billet, the seventh temperature induction image acquisition device obtains the thermal imaging information of the seventh continuous casting billet, the eighth temperature induction image acquisition device obtains the thermal imaging information of the eighth continuous casting billet, the ninth temperature induction image acquisition device obtains the thermal imaging information of the ninth continuous casting billet, and the tenth temperature induction image acquisition device obtains the thermal imaging information of the tenth continuous casting billet. A first image acquisition device is set at the end of the eighth section of the second slow cooling furnace for collecting the surface crack information of the continuous casting billet.

[0007] S3. Input the first continuous casting billet thermal imaging information, the second continuous casting billet thermal imaging information, the third continuous casting billet thermal imaging information, the fourth continuous casting billet thermal imaging information, the fifth continuous casting billet thermal imaging information, the sixth continuous casting billet thermal imaging information, the seventh continuous casting billet thermal imaging information, the eighth continuous casting billet thermal imaging information, the ninth continuous casting billet thermal imaging information, the tenth continuous casting billet thermal imaging information, and the surface crack information of the continuous casting billet into the training model. Obtain the slow cooling temperature drop rate information of the continuous casting billet from the training model. Use the surface crack information of the continuous casting billet as the test value, delete the unqualified slow cooling temperature drop rate information of the continuous casting billet, save the qualified slow cooling temperature drop rate information of the continuous casting billet, and input this set of qualified data into the training model for training. The qualified data set includes the first continuous casting billet thermal imaging information, the second continuous casting billet thermal imaging information, the third continuous casting billet thermal imaging information, the fourth continuous casting billet thermal imaging information, the fifth continuous casting billet thermal imaging information, the sixth continuous casting billet thermal imaging information, the seventh continuous casting billet thermal imaging information, the eighth continuous casting billet thermal imaging information, the ninth continuous casting billet thermal imaging information, the tenth continuous casting billet thermal imaging information, and the slow cooling temperature drop rate information of the continuous casting billet.

[0008] The surface crack information of the continuous casting billet includes the number, length, and width of the surface cracks of the continuous casting billet. Upper limit values for the number, length, and width of the surface cracks of the continuous casting billet are set, and if they do not exceed the upper limit values, it is considered qualified.

[0009] Further, the temperature set for the first stage of the first slow cooling furnace is 560 ± 5 °C, the temperature set for the second stage is 490 ± 5 °C, the temperature set for the third stage is 450 ± 5 °C, and the fourth stage is at room temperature.

[0010] Further, the temperature set for the first stage of the second slow cooling furnace is 790 ± 5 °C, the temperature set for the second stage is 720 ± 5 °C, the temperature set for the third stage is 650 ± 5 °C, the temperature set for the fourth stage is 600 ± 5 °C, the temperature set for the fifth stage is 550 ± 5 °C, the temperature set for the sixth stage is 500 ± 5 °C, the temperature set for the seventh stage is 450 ± 5 °C, and the eighth stage is at room temperature.

[0011] Further, the first continuous casting billet thermal imaging device, the second continuous casting billet thermal imaging device, the third continuous casting billet thermal imaging device, the fourth continuous casting billet thermal imaging device, the fifth continuous casting billet thermal imaging device, the sixth continuous casting billet thermal imaging device, the seventh continuous casting billet thermal imaging device, the eighth continuous casting billet thermal imaging device, the ninth continuous casting billet thermal imaging device, the tenth continuous casting billet thermal imaging device, and the first image acquisition device are connected to the processor.

[0012] Further, a first transportation mechanism is provided in the first slow cooling furnace, and the first transportation mechanism is used to continuously transport the continuous casting billet. A second transportation mechanism is provided in the second slow cooling furnace. The first transportation mechanism and the second transportation mechanism are connected to the processor. After the processor obtains qualified thermal imaging information of the continuous casting billet in the corresponding slow cooling section, the processor controls the operation of the first transportation mechanism or the second transportation mechanism to transport the continuous casting billet to the next section.

[0013] The present invention has beneficial effects:

[0014] The present invention provides a method for judging the slow cooling state of a continuous casting billet. By obtaining the thermal imaging information of the continuous casting billet in each stage through the temperature sensing image acquisition devices provided in each slow cooling stage, the slow cooling state of the continuous casting billet is judged, solving the problems of low efficiency and large error caused by multiple manual measurements of the temperature in the slow cooling pit. And the thermal imaging information of the continuous casting billet and the surface crack information of the continuous casting billet are trained through a training model to improve the recognition accuracy of the slow cooling state of the continuous casting billet and perform transportation control. Specific embodiments

[0015] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific circumstances.

[0016] Taking heat-resistant steel T5 as an example, bainite phase transformation will occur during the cooling process of heat-resistant steel T5. For the first "stress relief annealing", the temperature is raised to 560 ± 5 °C and held for a certain period of time to promote the gradual decomposition and transformation of ε-carbide particles in the bainite structure, and then slowly cooled until it is taken out of the furnace, quickly releasing the internal stress in the structure and reducing the probability of surface microcracks. Then, the second "softening annealing" treatment is carried out. The temperature is gradually raised to 790 ± 5 °C and held for 4 h, so that the bainite structure is completely dissolved and part of the θ-carbide in the pearlite structure is decomposed, and then slowly cooled until the structure is completely transformed into ferrite + dot-like carbide, reducing the hardness while eliminating stress.

[0017] Two slow cooling furnaces and a heating furnace are adopted. First, the first slow cooling furnace is used for the first "stress relief annealing" treatment, and then the second slow cooling furnace is used for the second "softening annealing" treatment.

[0018] The first slow cooling furnace includes four sections. The set temperature of the first section is 560 ± 5 °C, the set temperature of the second section is 490 ± 5 °C, the set temperature of the third section is 450 ± 5 °C, and the fourth section is at room temperature. When the continuous casting billet passes through the first slow cooling furnace, it is heated to the set temperature in the first section and held for 1 - 2 h, transported to the second section for slow cooling to the set temperature, transported to the third section for slow cooling to the set temperature, and finally transported to the fourth section for cooling to room temperature.

[0019] After the first "stress relief annealing" treatment, the continuous casting billet is gradually heated to 790 ± 5 °C in the heating furnace and then sent into the second slow cooling furnace. The second slow cooling furnace includes eight sections. The set temperature of the first section is 790 ± 5 °C, the set temperature of the second section is 720 ± 5 °C, the set temperature of the third section is 650 ± 5 °C, the set temperature of the fourth section is 600 ± 5 °C, the set temperature of the fifth section is 550 ± 5 °C, the set temperature of the sixth section is 500 ± 5 °C, the set temperature of the seventh section is 450 ± 5 °C, and the eighth section is at room temperature. After the continuous casting billet is held in the first section for 4 - 5 h, it is successively transported to other sections for slow cooling to the set temperature, and finally cooled to room temperature in the eighth section.

[0020] A first transportation mechanism is provided in the first slow cooling furnace, and the first transportation mechanism is used for continuously transporting the continuous casting billet. A second transportation mechanism is provided in the second slow cooling furnace.

[0021] Three temperature induction image acquisition devices are arranged in the first slow cooling furnace, namely the first temperature induction image acquisition device, the second temperature induction image acquisition device, and the third temperature induction image acquisition device. The first temperature induction image acquisition device is arranged at the end of the first section of the first slow cooling furnace, the second temperature induction image acquisition device is arranged at the end of the second section of the first slow cooling furnace, and the third temperature induction image acquisition device is arranged at the end of the third section of the first slow cooling furnace. The first temperature induction image acquisition device obtains the thermal imaging information of the first continuous casting billet, the second temperature induction image acquisition device obtains the thermal imaging information of the second continuous casting billet, and the third temperature induction image acquisition device obtains the thermal imaging information of the third continuous casting billet.

[0022] Seven temperature induction image acquisition devices are arranged in the second slow cooling furnace, namely the fourth temperature induction image acquisition device, the fifth temperature induction image acquisition device, the sixth temperature induction image acquisition device, the seventh temperature induction image acquisition device, the eighth temperature induction image acquisition device, the ninth temperature induction image acquisition device, and the tenth temperature induction image acquisition device. The fourth temperature induction image acquisition device is arranged at the end of the first section of the second slow cooling furnace, the fifth temperature induction image acquisition device is arranged at the end of the second section of the second slow cooling furnace, the sixth temperature induction image acquisition device is arranged at the end of the third section of the second slow cooling furnace, the seventh temperature induction image acquisition device is arranged at the end of the fourth section of the second slow cooling furnace, the eighth temperature induction image acquisition device is arranged at the end of the fifth section of the second slow cooling furnace, the ninth temperature induction image acquisition device is arranged at the end of the sixth section of the second slow cooling furnace, and the tenth temperature induction image acquisition device is arranged at the end of the seventh section of the second slow cooling furnace. The fourth temperature induction image acquisition device obtains the thermal imaging information of the fourth continuous casting billet, the fifth temperature induction image acquisition device obtains the thermal imaging information of the fifth continuous casting billet, the sixth temperature induction image acquisition device obtains the thermal imaging information of the sixth continuous casting billet, the seventh temperature induction image acquisition device obtains the thermal imaging information of the seventh continuous casting billet, the eighth temperature induction image acquisition device obtains the thermal imaging information of the eighth continuous casting billet, the ninth temperature induction image acquisition device obtains the thermal imaging information of the ninth continuous casting billet, and the tenth temperature induction image acquisition device obtains the thermal imaging information of the tenth continuous casting billet.

[0023] A first image acquisition device is arranged at the end of the eighth section of the second slow cooling furnace for collecting the surface crack information of the continuous casting billet.

[0024] The first continuous casting billet thermal imaging device, the second continuous casting billet thermal imaging device, the third continuous casting billet thermal imaging device, the fourth continuous casting billet thermal imaging device, the fifth continuous casting billet thermal imaging device, the sixth continuous casting billet thermal imaging device, the seventh continuous casting billet thermal imaging device, the eighth continuous casting billet thermal imaging device, the ninth continuous casting billet thermal imaging device, the tenth continuous casting billet thermal imaging device, and the first image acquisition device are connected to a processor. The processor inputs the first continuous casting billet thermal imaging information, the second continuous casting billet thermal imaging information, the third continuous casting billet thermal imaging information, the fourth continuous casting billet thermal imaging information, the fifth continuous casting billet thermal imaging information, the sixth continuous casting billet thermal imaging information, the seventh continuous casting billet thermal imaging information, the eighth continuous casting billet thermal imaging information, the ninth continuous casting billet thermal imaging information, the tenth continuous casting billet thermal imaging information, and the continuous casting billet surface crack information into a training model, which is a neural network model in machine learning. The training model is obtained by training with multiple sets of qualified training data. The continuous casting billet slow cooling temperature drop rate information is obtained from the training model. The continuous casting billet surface crack information is used as a verification value to screen out unqualified continuous casting billet slow cooling temperature drop rate information, save the qualified continuous casting billet slow cooling temperature drop rate information, and input this set of qualified data into the training model for training. The qualified data set includes the first continuous casting billet thermal imaging information, the second continuous casting billet thermal imaging information, the third continuous casting billet thermal imaging information, the fourth continuous casting billet thermal imaging information, the fifth continuous casting billet thermal imaging information, the sixth continuous casting billet thermal imaging information, the seventh continuous casting billet thermal imaging information, the eighth continuous casting billet thermal imaging information, the ninth continuous casting billet thermal imaging information, the tenth continuous casting billet thermal imaging information, and the continuous casting billet slow cooling temperature drop rate information.

[0025] The continuous casting billet surface crack information includes the number, length, and width of the continuous casting billet surface cracks. The upper limit values of the number, length, and width of the continuous casting billet surface cracks are set, and if they do not exceed the upper limit values, they are considered qualified.

[0026] The first transportation mechanism and the second transportation mechanism are connected to the processor. In the corresponding slow cooling section, after the processor obtains the qualified continuous casting billet thermal imaging information, the processor controls the corresponding transportation mechanism to operate to transport the continuous casting billet to the next section.

[0027] Temperature induction image acquisition devices are installed in the first slow cooling furnace and the second slow cooling furnace, and thermal insulation protection is adopted to ensure both the acquisition of images and the safe operating environment of the temperature induction image acquisition devices.

[0028] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention in other forms. Any person skilled in the relevant art may use the disclosed technical content to make changes or modifications into equivalent embodiments with equivalent changes and apply them to other fields. However, as long as it does not depart from the technical solution content of the present invention, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for judging the slow cooling state of continuous casting billets, characterized in that: Specifically, it includes the following steps: S1. Feed the continuous casting billet of T5 heat-resistant steel into the first slow cooling furnace, which includes four sections. When the continuous casting billet passes through the first slow cooling furnace, it is heated to a set temperature in the first section and kept warm for 1 - 2 hours, then transported to the second section for slow cooling to the set temperature, then transported to the third section for slow cooling to the set temperature, and finally transported to the fourth section for cooling to room temperature. Three temperature induction image acquisition devices are arranged in the first slow cooling furnace, namely the first temperature induction image acquisition device, the second temperature induction image acquisition device, and the third temperature induction image acquisition device. Among them, the first temperature induction image acquisition device is arranged at the end of the first section of the first slow cooling furnace, the second temperature induction image acquisition device is arranged at the end of the second section of the first slow cooling furnace, and the third temperature induction image acquisition device is arranged at the end of the third section of the first slow cooling furnace. The first temperature induction image acquisition device obtains the first continuous casting billet thermal imaging information, the second temperature induction image acquisition device obtains the second continuous casting billet thermal imaging information, and the third temperature induction image acquisition device obtains the third continuous casting billet thermal imaging information; S2. Gradually heat the continuous casting billet of T5 heat-resistant steel to 790 ± 5 °C, and then feed it into the second slow cooling furnace, which includes eight sections. After the continuous casting billet is kept warm for 4 - 5 hours in the first section, it is successively transported to other sections for slow cooling to the set temperature, and finally cooled to room temperature in the eighth section. Seven temperature induction image acquisition devices are arranged in the second slow cooling furnace, namely the fourth temperature induction image acquisition device, the fifth temperature induction image acquisition device, the sixth temperature induction image acquisition device, the seventh temperature induction image acquisition device, the eighth temperature induction image acquisition device, the ninth temperature induction image acquisition device, and the tenth temperature induction image acquisition device; The fourth temperature induction image acquisition device is arranged at the end of the first section of the second slow cooling furnace, the fifth temperature induction image acquisition device is arranged at the end of the second section of the second slow cooling furnace, the sixth temperature induction image acquisition device is arranged at the end of the third section of the second slow cooling furnace, the seventh temperature induction image acquisition device is arranged at the end of the fourth section of the second slow cooling furnace, the eighth temperature induction image acquisition device is arranged at the end of the fifth section of the second slow cooling furnace, the ninth temperature induction image acquisition device is arranged at the end of the sixth section of the second slow cooling furnace, and the tenth temperature induction image acquisition device is arranged at the end of the seventh section of the second slow cooling furnace. The fourth temperature induction image acquisition device obtains the fourth continuous casting billet thermal imaging information, the fifth temperature induction image acquisition device obtains the fifth continuous casting billet thermal imaging information, the sixth temperature induction image acquisition device obtains the sixth continuous casting billet thermal imaging information, the seventh temperature induction image acquisition device obtains the seventh continuous casting billet thermal imaging information, the eighth temperature induction image acquisition device obtains the eighth continuous casting billet thermal imaging information, the ninth temperature induction image acquisition device obtains the ninth continuous casting billet thermal imaging information, and the tenth temperature induction image acquisition device obtains the tenth continuous casting billet thermal imaging information. A first image acquisition device is arranged at the end of the eighth section of the second slow cooling furnace for collecting the surface crack information of the continuous casting billet; S3. Input the thermal imaging information of the first continuous casting billet, the second continuous casting billet, the third continuous casting billet, the fourth continuous casting billet, the fifth continuous casting billet, the sixth continuous casting billet, the seventh continuous casting billet, the eighth continuous casting billet, the ninth continuous casting billet, the tenth continuous casting billet, and the surface crack information of the continuous casting billet into the training model. Obtain the slow cooling temperature drop rate information of the continuous casting billet from the training model. Use the surface crack information of the continuous casting billet as the inspection value, select and eliminate the unqualified slow cooling temperature drop rate information of the continuous casting billet, save the qualified slow cooling temperature drop rate information of the continuous casting billet, and input the qualified data group into the training model for training. The qualified data group includes the thermal imaging information of the first continuous casting billet, the second continuous casting billet, the third continuous casting billet, the fourth continuous casting billet, the fifth continuous casting billet, the sixth continuous casting billet, the seventh continuous casting billet, the eighth continuous casting billet, the ninth continuous casting billet, the tenth continuous casting billet, and the slow cooling temperature drop rate information of the continuous casting billet; The surface crack information of the continuous casting billet includes the number, length, and width of the surface cracks of the continuous casting billet. Set the upper limit values of the number, length, and width of the surface cracks of the continuous casting billet. If it does not exceed the upper limit value, it is qualified.

2. The continuous casting billet slow cooling state judgment method according to claim 1, characterized in that: The set temperature of the first section of the first slow cooling furnace is 560 ± 5 °C, the second section is 490 ± 5 °C, the third section is 450 ± 5 °C, and the fourth section is at room temperature.

3. A method for judging the slow cooling state of a continuous casting billet according to claim 1 or 2, characterized in that: The set temperature of the first section of the second slow cooling furnace is 790 ± 5 °C, the second section is 720 ± 5 °C, the third section is 650 ± 5 °C, the fourth section is 600 ± 5 °C, the fifth section is 550 ± 5 °C, the sixth section is 500 ± 5 °C, the seventh section is 450 ± 5 °C, and the eighth section is at room temperature.

4. The continuous casting slab slow cooling state judgment method according to claim 1, characterized in that: The first thermal imaging device for continuous casting billets, the second thermal imaging device for continuous casting billets, the third thermal imaging device for continuous casting billets, the fourth thermal imaging device for continuous casting billets, the fifth thermal imaging device for continuous casting billets, the sixth thermal imaging device for continuous casting billets, the seventh thermal imaging device for continuous casting billets, the eighth thermal imaging device for continuous casting billets, the ninth thermal imaging device for continuous casting billets, the tenth thermal imaging device for continuous casting billets, and the first image acquisition device are connected to the processor.

5. The method for judging the slow cooling state of a continuous casting billet according to claim 4, characterized in that: A first transportation mechanism is provided in the first slow cooling furnace. The first transportation mechanism is used to continuously transport the continuous casting billet. A second transportation mechanism is provided in the second slow cooling furnace. The first transportation mechanism and the second transportation mechanism are connected to the processor. In the corresponding slow cooling section, after the processor obtains the qualified thermal imaging information of the continuous casting billet, the processor controls the operation of the first transportation mechanism or the second transportation mechanism to transport the continuous casting billet to the next section.