A rare earth corrosion resistant steel preparation process

Abstract

The present invention relates to the technical field of metal materials, and in particular to a rare earth corrosion-resistant steel preparation process. The metal impurity area collected by an image detection device is used to determine the position of the inert gas in the ladle, and the inert gas flow rate is controlled according to the comparison result between the metal impurity area and the preset metal impurity area; a metal impurity salvage amount change curve is generated according to the metal impurity salvage amount and the metal impurity salvage time, and whether to open the non-metallic impurity detection is determined according to the change curve analysis result; when determining to perform non-metallic impurity detection, the non-metallic impurity content in the ladle is detected by the propagation speed of ultrasonic waves in the ladle, and the inert gas pressure is adjusted according to the detection result; the inert gas heat evaluation value is adjusted according to the difference between the temperature in the ladle after removing impurities and the standard temperature in the ladle. The present invention can effectively remove impurities in the ladle, so that the purity of molten steel is high and the quality of steel is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of metal materials, and in particular to a preparation process of rare earth corrosion-resistant steel. Background Art

[0002] The new rare earth corrosion-resistant steel has a 30-50% higher atmospheric corrosion resistance than traditional plain carbon steel and low alloy steel in atmospheric environment. Rare earth corrosion-resistant steel structures can be exempted from painting and galvanizing. The service life of general galvanized steel is about 15 years, and rare earth corrosion-resistant steel can extend the service life to more than 70 years, reducing the environmental burden and facilitating the rational application of resources. Plain carbon steel is formed into corrosion-resistant steel through rare earth alloying, and the cost per ton of steel is only increased by 30-50 yuan, which is significantly lower than the cost of commonly used copper-phosphorus-chromium-nickel weathering steel.

[0003] Chinese patent publication number: CN106834961A. A preparation process of highly corrosion-resistant steel is disclosed, including: a preparation process of highly corrosion-resistant steel, the components by weight percentage are: C: 0.3-0.5%, Cr: 12-16%, Co: 1.2-1.6%, Mn: 0.2-0.6%, Si: 0.2-0.8%, Mo: 0.9-1.5%, V: 0.05-0.2%, Ti: 0.05-0 .5%, rare earth RE: 0.05-0.5% and the balance iron, adopting the production process of converter primary smelting, refining and continuous casting, which is characterized by: first adding L08 molten iron and scrap steel during the converter smelting process; refining through LF furnace, refining temperature: 1500°C~1650°C; fine-tuning of components, slag deoxidation, refining time>30 minutes; argon blowing and stirring throughout the process; refined slag basicity CaO / SiO2: <5.0; making the chemical composition meet the component requirements of steel; finally continuous casting at 1500°C~1550°C.

[0004] It can be seen that the prior art has the following problems: impurities in the ladle cannot be effectively removed, resulting in low purity of molten steel and affecting steel quality. Summary of the invention

[0005] To this end, the present invention provides a rare earth corrosion-resistant steel preparation process to overcome the problem in the prior art that impurities in the ladle cannot be effectively removed, resulting in low purity of molten steel and affecting steel quality.

[0006] To achieve the above object, the present invention provides a rare earth corrosion-resistant steel preparation process, comprising:

[0007] Inert gas is introduced into the ladle to salvage the metal impurities in the ladle in stages;

[0008] The metal impurity area collected by the image detection device is used to determine the position where the inert gas is introduced into the ladle based on the metal impurity area, and the inert gas flow rate is controlled according to the comparison result between the metal impurity area and the preset metal impurity area;

[0009] Generate a metal impurity salvage volume change curve based on the metal impurity salvage volume and the metal impurity salvage time, and determine whether to start non-metallic impurity detection based on the change curve analysis results;

[0010] When determining to conduct non-metallic impurity detection, the non-metallic impurity content in the ladle is detected by the propagation speed of ultrasonic waves in the ladle, and the inert gas pressure is adjusted according to the detection results;

[0011] The inert gas heat evaluation value is adjusted according to the difference between the temperature inside the ladle after removing impurities and the standard temperature inside the ladle.

[0012] Furthermore, the metal impurity salvaging stage is divided into a first salvaging stage and a second salvaging stage according to the metal impurity area in the ladle and the salvaged amount of the metal impurities in the ladle.

[0013] Furthermore, a metal impurity area change curve is generated according to the change of the metal impurity area per unit time in the first salvage stage, and it is determined whether to adjust the release rate of the inert gas at the bottom of the ladle according to the change of the slope of the metal impurity area change curve per unit time, and it is determined whether to open the inert gas port at the side of the ladle to stir the metal impurities according to the change of the slope of the metal impurity area change curve after the inert gas release rate is adjusted.

[0014] Furthermore, the metal impurity salvage volume variation curve is generated according to the metal impurity salvage volume per unit time in the second salvage stage, and whether to start the detection of non-metallic impurities is determined according to the comparison result between the metal impurity salvage volume variation curve and the set standard metal impurity salvage volume.

[0015] Furthermore, the ultrasonic wave propagation velocity through the ladle is measured by an ultrasonic velocity measuring device, and the non-metallic impurity content in the ladle is estimated based on the ultrasonic wave propagation velocity measurement result.

[0016] Furthermore, the initial pressure value of the inert gas introduced into the ladle is adjusted by estimating the non-metallic impurity content in the ladle.

[0017] Furthermore, it is determined whether to perform a secondary adjustment on the gas pressure value of the inert gas according to a comparison result between an actual measured value of the ultrasonic wave propagation velocity after the initial pressure adjustment of the inert gas and a preset first ultrasonic wave propagation velocity.

[0018] Furthermore, an inert gas pressure evaluation value is generated according to the average existence time of the inert gas bubbles and the average diameter of the inert gas bubbles, and whether the remaining amount of non-metallic impurities in the ladle meets the standard is determined according to the inert gas pressure evaluation value.

[0019] Furthermore, an inert gas thermal evaluation value is generated according to the inert gas temperature and the inert gas pressure.

[0020] Furthermore, the inert gas thermal evaluation value is adjusted according to the difference between the preset standard temperature in the ladle and the actual temperature in the ladle.

[0021] Compared with the prior art, the beneficial effect of the present invention is that, by dividing the salvaging metal impurities stage into a first salvaging stage and a second salvaging stage, the metal impurities in the ladle can be effectively removed according to different salvaging stages, so as to avoid the molten steel failing to meet the requirements and affecting the quality of the finished product due to the metal impurity content in the ladle being higher than the standard content. If reprocessing is required, it is not only time-consuming and labor-intensive but also consumes too much money and manpower. In the first salvaging stage, a metal impurity area change curve is generated according to the metal impurity area change in the ladle collected by the image detection device, so that the first salvage stage of the metal impurity salvage in the ladle can be more intuitively and accurately salvaged, and a large area of ​​impurities can be salvaged, so as to avoid the omission of the salvage of a large area of ​​impurities and the incomplete salvage of impurities affecting the quality of the finished product. In the second salvage stage, a metal impurity salvage amount change curve is generated according to the metal impurity salvage amount change amount collected by the salvage device, so that the metal impurities in the second salvage stage can be more thoroughly salvaged and removed, so as to avoid the product quality being affected by a small part of the metal impurities not being salvaged, and the metal impurities in the ladle can be better salvaged.

[0022] Furthermore, in the first salvage stage, the change in the area of ​​metal impurities per unit time generates a metal impurity area change curve, and whether to adjust the release rate of the inert gas at the bottom of the ladle is determined according to the change in the slope of the metal impurity area change curve per unit time. The adjustment can be made according to the slope of the metal impurity area change. If the impurity area of ​​the metal impurities gradually increases when the metal impurities are stirred in the ladle at the initial speed of the released inert gas, the release rate of the inert gas at the bottom of the ladle is not adjusted, and the inert gas is released at the initial speed of the released inert gas, so that the metal impurities can be agglomerated at a fixed speed and salvaged, thereby ensuring the integrity of the metal impurity salvage. If the impurity area of ​​the metal impurities gradually decreases when the metal impurities are stirred in the ladle at the initial speed of the released inert gas, the release rate of the inert gas at the bottom of the ladle is adjusted to accelerate the release rate of the inert gas at the bottom of the ladle, so that the metal impurities in the ladle can be further separated from the molten steel in the ladle, and the metal impurities in the ladle can be effectively salvaged.

[0023] Furthermore, the second salvage stage is a stage in which the inert gas port on the inner side of the ladle is opened to stir the metal impurities. When the metal impurities are stirred through the inert gas port on the bottom of the ladle in the first salvage stage, the metal impurities attached to the inner wall of the ladle can be stirred again to make them fall off and be salvaged. In the second salvage stage, a metal impurity salvage amount change curve is generated according to the metal impurity salvage amount per unit time, and the remaining metal impurities in the ladle can be measured intuitively. If the values ​​in the salvage amount change interval in three consecutive unit time salvage amount change intervals are all greater than the standard metal impurity salvage amount, the metal impurities in the ladle continue to be salvaged; if three consecutive unit time salvage amount change intervals are greater than the standard metal impurity salvage amount, the metal impurities in the ladle continue to be salvaged; If any of the values ​​in the salvage volume change interval of the unit time is greater than the standard metal impurity salvage volume, the metal impurities in the ladle will continue to be salvaged; if any of the values ​​in the salvage volume change interval of three consecutive unit time are less than or equal to the standard metal impurity salvage volume, the salvage of the metal impurities in the ladle will be stopped, and the detection of non-metallic impurities will be started. When the values ​​in the salvage volume change interval are less than or equal to the standard metal impurity salvage volume, the metal impurities in the ladle are already very few, which can meet the metal impurity retention ratio in the ladle, avoiding energy waste due to excessive salvage of residual metal impurities in the ladle, affecting work efficiency.

[0024] Furthermore, ultrasonic detection of non-metallic impurity content in the ladle can accurately estimate the non-metallic impurity content in the ladle. Since the propagation speed of ultrasonic waves in pure molten steel is a known condition, the propagation speed of ultrasonic waves in the ladle is actually measured. By calculating the difference between the standard propagation speed of ultrasonic waves and the actual propagation speed in the ladle, the non-metallic impurity content in the ladle can be accurately estimated, thereby ensuring product quality.

[0025] Furthermore, the initial pressure value of the inert gas introduced into the ladle is adjusted according to the estimated value of the non-metallic impurity content in the ladle, so that the non-metallic impurities in the ladle can be better removed according to the actual situation. When the calculated inert gas pressure value is less than the first inert gas pressure value, the first inert gas pressure value is selected as the initial pressure value, which can avoid the situation where the calculated inert gas pressure value is too small and the inert gas bubbles that carry out the non-metallic impurities cannot be generated, thereby failing to remove the non-metallic impurities; when the calculated inert gas pressure value is greater than or equal to the first inert gas pressure value and less than or equal to the second inert gas pressure value, the calculated inert gas pressure value is the initial pressure value, which can ensure that the inert gas pressure is within a suitable range and effectively carry out the non-metallic impurities in the ladle; when the calculated inert gas pressure value is greater than the second inert gas pressure value, the second inert gas pressure value is selected as the initial pressure value, which can avoid the situation where the inert gas bubbles are too large and rise too fast when the calculated pressure is too large, resulting in a drop in temperature in the ladle and affecting product quality.

[0026] Furthermore, the pressure value of the inert gas is secondary adjusted to determine the difference between the actual measured value of the ultrasonic propagation velocity after the initial pressure adjustment of the inert gas and the preset first ultrasonic propagation velocity, which can avoid residual non-metallic impurities in the ladle. When the inert gas pressure is relatively high, the bubbles are relatively large, which can initially bring out the non-metallic impurities in the ladle. If the actual measured value of the ultrasonic propagation velocity after adjustment is less than the preset first ultrasonic propagation velocity, and the velocity remains unchanged for two consecutive unit times, the inert gas pressure value is secondary adjusted to ensure that when the inert gas pressure decreases, the bubbles become smaller and rise more gently, and the non-metallic impurities in the ladle are brought out more evenly.

[0027] Furthermore, when the impurity content in the ladle is greater than the preset standard non-metallic impurity residual amount, the inert gas bubble pressure value is adjusted so that the inert gas pressure evaluation value is within the preset evaluation value range, so that the generated inert gas bubbles can be uniform and maintain a certain carrying-out speed to effectively carry out the non-metallic impurities, thereby avoiding residual non-metallic impurities from mixing in the molten steel in the ladle and affecting the quality of the finished steel.

[0028] Furthermore, when the difference between the preset standard ladle temperature and the actual temperature in the ladle is less than the first ladle temperature difference, the inert gas heat evaluation value is adjusted to a smaller value, which can ensure that the inert gas does not need to move violently when the temperature difference in the ladle is small, thereby reducing equipment loss; when the difference between the preset standard ladle temperature and the actual temperature in the ladle is greater than the second ladle temperature difference, the inert gas heat evaluation value is adjusted to a higher value, which can ensure that when the temperature difference in the ladle is large, the inert gas can pass through the ladle faster, thereby taking away excess heat faster, lowering the temperature, and improving the ladle cooling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a flow chart of the rare earth corrosion-resistant steel preparation process in this embodiment;

[0030] Figure 2 This is a flow chart for determining the first salvage stage of the rare earth corrosion-resistant steel preparation process in this embodiment;

[0031] Figure 3 This is a flow chart for determining the second salvage stage of the rare earth corrosion-resistant steel preparation process in this embodiment;

[0032] Figure 4 This is a flow chart of removing non-metallic impurities in the rare earth corrosion-resistant steel preparation process in this embodiment. DETAILED DESCRIPTION

[0033] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0035] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0036] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] See also Figure 1-Figure 4 As shown, Figure 1 This is a flow chart of the rare earth corrosion-resistant steel preparation process in this embodiment; Figure 2 This is a flow chart of the first salvage stage of the rare earth corrosion-resistant steel preparation process in this embodiment; Figure 3 This is a flow chart of the second salvage stage of the rare earth corrosion-resistant steel preparation process in this embodiment; Figure 4 This is a flow chart of removing non-metallic impurities in the rare earth corrosion-resistant steel preparation process in this embodiment.

[0038] This embodiment provides a rare earth corrosion resistant steel preparation process, comprising the following steps:

[0039] Step 100, inert gas is introduced into the ladle, and a salvaging device salvages metal impurities in the ladle in stages;

[0040] Step 200, determining the position where the inert gas is introduced into the ladle based on the metal impurity area collected by the image detection device, and controlling the inert gas flow rate according to the comparison result between the metal impurity area and the preset metal impurity area;

[0041] Step 300, generating a metal impurity salvage amount change curve according to the metal impurity salvage amount and the metal impurity salvage time, and determining whether to start non-metallic impurity detection according to the change curve analysis result;

[0042] Step 400, when it is determined to perform non-metallic impurity detection, the non-metallic impurity content in the ladle is detected by the propagation speed of ultrasonic waves in the ladle, and the inert gas pressure is adjusted according to the detection result;

[0043] Step 500, adjusting the temperature of the inert gas according to the temperature of the molten steel in the ladle after the impurities are removed and the pressure of the inert gas.

[0044] Specifically, the metal impurity salvaging stage is divided into a first salvaging stage and a second salvaging stage according to the metal impurity area in the ladle and the amount of metal impurities salvaged in the ladle.

[0045] The image acquisition device detects the metal impurity area Sa in the ladle, generates a metal impurity area change curve F(Sa) according to the metal impurity area Sa, and divides the metal impurity area change curve F(Sa) into a first area change interval F(Sa1), a second area change interval F(Sa2), ..., an nth area change interval F(San) according to a unit time T.

[0046] The salvage device detects the salvaged amount Ga of metal impurities in the ladle, generates a metal impurity salvage amount variation curve F(Ga) according to the metal impurity salvage amount Ga, and divides the metal impurity salvage amount variation curve F(Ga) into a first salvage amount variation interval F(Ga1), a second salvage amount variation interval F(Ga2), ..., an nth salvage amount variation interval F(Gan) according to a unit time T.

[0047] By dividing the salvaging metal impurities stage into a first salvaging stage and a second salvaging stage, the metal impurities in the ladle can be effectively removed according to different salvaging stages, so as to avoid the molten steel failing to meet the requirements and affecting the quality of the finished product due to the metal impurity content in the ladle being higher than the standard content. If reprocessing is required, it is not only time-consuming and labor-intensive, but also consumes too much money and manpower. In the first salvaging stage, a metal impurity area change curve is generated according to the metal impurity area change in the ladle collected by the image detection device, so that the first salvage stage of the metal impurity salvage in the ladle can be more intuitively salvaged more accurately, and a large area of ​​impurities can be salvaged, so as to avoid the omission of the salvage of a large area of ​​impurities resulting in incomplete impurity salvage and affecting the quality of the finished product. In the second salvage stage, a metal impurity salvage amount change curve is generated according to the metal impurity salvage amount change collected by the salvage device, so that the metal impurities in the second salvage stage can be salvaged and removed more thoroughly, so as to avoid the product quality being affected by a small part of the metal impurities not being salvaged, and the metal impurities in the ladle can be salvaged better.

[0048] Specifically, a metal impurity area change curve is generated according to the change of the metal impurity area per unit time in the first salvage stage, and it is determined whether to adjust the release rate of the inert gas at the bottom of the ladle according to the change of the slope of the metal impurity area change curve per unit time; and it is determined whether to open the inert gas port at the side of the ladle to stir the metal impurities according to the change of the slope of the metal impurity area change curve after the inert gas release rate is adjusted.

[0049] Set the stop salvage area Sa1,

[0050] The slopes of the area change intervals are analyzed to obtain the first area change interval slope Ka1, the second area change interval slope Ka2, ..., the nth area change interval slope Kan,

[0051] Select any area change interval slope Kai, i=1,2,3,...,n,

[0052] If the slope Kai of any selected area change interval is greater than the previous unit time T i-1 The slope Ka i-1， The release rate of the inert gas at the bottom of the ladle is not adjusted, and the inert gas is released at the initial release rate Va;

[0053] If the slope Kai of any selected area change interval is less than or equal to the previous unit time T i-1 The slope Ka i-1 , then the release rate of the inert gas at the bottom of the ladle is adjusted;

[0054] The release rate of inert gas after adjustment at the bottom of the ladle is Vb, Vb = Va + (Kai-Ka i-1 )×c1+Vc, where c1 is the compensation parameter for the influence of the slope difference of adjacent unit time area change intervals on the release rate of the inert gas after adjustment at the bottom of the ladle, and Vc is the inert gas release rate constant;

[0055] The slope of the metal impurity area change curve per unit time after adjusting the inert gas release rate Vb is determined.

[0056] If the metal impurity area Sa increases after adjusting the inert gas release rate Vb, the salvaging device continues to salvage until the data collected by the image detection device shows that the metal impurity area Sa is equal to or smaller than the stop salvage area Sa1, then the inert gas port on the side of the ladle is opened to stir the metal impurities;

[0057] If the slope difference of the metal impurity area change interval after adjusting the inert gas release rate Vb is 0, the inert gas port on the side of the ladle is opened to stir the metal impurities.

[0058] In the first salvage stage, the change of the metal impurity area per unit time generates a metal impurity area change curve, and whether to adjust the release rate of the inert gas at the bottom of the ladle is determined according to the change of the slope of the metal impurity area change curve per unit time. The adjustment can be made according to the slope of the metal impurity area change. If the impurity area of ​​the metal impurities gradually increases after the metal impurities are stirred in the ladle at the initial speed of releasing the inert gas, the release rate of the inert gas at the bottom of the ladle is not adjusted, and the inert gas is released at the initial speed of releasing the inert gas, so that the metal impurities can be agglomerated at a fixed speed and salvaged, thereby ensuring the integrity of the metal impurity salvage. If the impurity area of ​​the metal impurities gradually decreases after the metal impurities are stirred in the ladle at the initial speed of releasing the inert gas, the release rate of the inert gas at the bottom of the ladle is adjusted to speed up the release rate of the inert gas at the bottom of the ladle, so that the metal impurities in the ladle can be further separated from the molten steel in the ladle, and the metal impurities in the ladle can be effectively salvaged.

[0059] Specifically, the metal impurity salvage volume variation curve is generated according to the metal impurity salvage volume per unit time in the second salvage stage, and whether to start the detection of non-metallic impurities is determined according to the comparison result between the metal impurity salvage volume variation curve and the set standard metal impurity salvage volume.

[0060] Obtain the metal impurity salvage volume change curve F (Ga), select any three consecutive salvage volume change intervals per unit time, F (Ga m-1 ), F (Ga m ), F (Ga m+1 )、m=2,3,...,n,

[0061] Set the standard metal impurity salvage volume Gab,

[0062] If the salvage volume change interval F (Ga m-1 ) are all greater than the standard metal impurity salvage volume Gab, and the salvage volume variation range F (Ga m ) are all greater than the standard metal impurity salvage volume Gab, and the salvage volume variation range F (Ga m-1 ) are all greater than the standard metal impurity salvage volume Gab, then continue to salvage the metal impurities in the ladle;

[0063] If the salvage volume change interval F (Ga m-1 ), F (Ga m ) and F(Ga m-1 ) If any value in the salvage volume change range is greater than the standard metal impurity salvage volume Gab, the metal impurities in the ladle will continue to be salvaged;

[0064] If the salvage volume change interval F (Ga m-1 ), F (Ga m ) and F(Ga m-1 ) If any value in the salvage volume change range is less than or equal to the standard metal impurity salvage volume Gab, the salvage of metal impurities in the ladle is stopped and the detection of non-metallic impurities is started at the same time.

[0065] The second salvage stage is a stage in which the inert gas port on the inner side of the ladle is opened to stir the metal impurities. When the metal impurities are stirred through the inert gas port on the bottom of the ladle in the first salvage stage, the metal impurities attached to the inner wall of the ladle can be stirred again to make them fall off and be salvaged. In the second salvage stage, a metal impurity salvage amount change curve is generated according to the metal impurity salvage amount per unit time, and the remaining metal impurities in the ladle can be measured intuitively. If the values ​​in the salvage amount change interval for three consecutive unit times are all greater than the standard metal impurity salvage amount, the metal impurities in the ladle continue to be salvaged; if the values ​​in the salvage amount change interval for three consecutive unit times are .... If any value in the salvage volume change interval is greater than the standard metal impurity salvage volume, the metal impurities in the ladle will continue to be salvaged; if any value in the salvage volume change interval is less than or equal to the standard metal impurity salvage volume for three consecutive unit time intervals, the salvage of metal impurities in the ladle will be stopped, and the detection of non-metallic impurities will be started. When the values ​​in the salvage volume change interval are less than or equal to the standard metal impurity salvage volume, the metal impurities in the ladle are already very few, which can meet the metal impurity retention ratio in the ladle, avoiding energy waste due to excessive salvage of residual metal impurities in the ladle, affecting work efficiency.

[0066] Specifically, the ultrasonic propagation velocity of the ultrasonic wave passing through the ladle is measured by an ultrasonic velocity measuring device, and the non-metallic impurity content in the ladle is estimated based on the ultrasonic propagation velocity measurement result.

[0067] The ultrasonic velocity measuring device measures the ultrasonic propagation velocity through the ladle, and the actual measured value is Vs. The standard propagation velocity of the ultrasonic wave in the ladle is set to Vsb.

[0068] The non-metallic impurity content in the ladle is E=(Vsb-Vs)×q1, where q1 is the compensation parameter for the influence of the difference between the standard ultrasonic propagation velocity in the ladle and the actual measured value on the non-metallic impurity content in the ladle.

[0069] By detecting the non-metallic impurity content in the ladle with ultrasound, the non-metallic impurity content in the ladle can be accurately estimated. Since the propagation speed of ultrasound in pure molten steel is a known condition, the propagation speed of ultrasound in the ladle is actually measured. By calculating the difference between the standard propagation speed of ultrasound and the actual propagation speed in the ladle, the non-metallic impurity content in the ladle can be accurately estimated, thereby ensuring product quality.

[0070] Specifically, the initial pressure value of the inert gas introduced into the ladle is adjusted by estimating the non-metallic impurity content in the ladle.

[0071] Set the first inert gas pressure value L1, the second inert gas pressure value L2, and the first ultrasonic wave propagation speed Vs1 in the ladle.

[0072] The initial pressure value of the inert gas is determined by the non-metallic impurity content in the ladle.

[0073] The initial pressure value of the inert gas La=E×q2, where q2 is the image compensation parameter of the non-metallic impurity content in the ladle to the initial pressure value of the inert gas.

[0074] If La<L1, the first pressure value L1 of the inert gas is selected as the initial pressure value;

[0075] If L1≤La≤L2, select La as the initial pressure value of the inert gas;

[0076] If La>L2, the second pressure value L2 of the inert gas is selected as the initial pressure value.

[0077] The initial pressure value of the inert gas introduced into the ladle is adjusted according to the estimated value of the non-metallic impurity content in the ladle, so that the non-metallic impurities in the ladle can be better removed according to the actual situation. When the calculated inert gas pressure value is less than the first inert gas pressure value, the first inert gas pressure value is selected as the initial pressure value, which can avoid the situation that when the calculated inert gas pressure value is too small, the inert gas bubbles that can carry out the non-metallic impurities cannot be generated, thereby failing to remove the non-metallic impurities; when the calculated inert gas pressure value is greater than or equal to the first inert gas pressure value and less than or equal to the second inert gas pressure value, the calculated inert gas pressure value is the initial pressure value, which can ensure that the inert gas pressure is within a suitable range and effectively carry out the non-metallic impurities in the ladle; when the calculated inert gas pressure value is greater than the second inert gas pressure value, the second inert gas pressure value is selected as the initial pressure value, which can avoid the situation that when the calculated pressure is too large, the inert gas bubbles are too large and rise too fast, resulting in a drop in temperature in the ladle and affecting product quality.

[0078] Specifically, whether to perform secondary adjustment on the gas pressure value of the inert gas is determined based on a comparison result between an actual measured value of the ultrasonic wave propagation velocity after the initial pressure adjustment of the inert gas and a preset first ultrasonic wave propagation velocity.

[0079] When the actual measured value of the ultrasonic propagation velocity after adjustment is less than the preset first ultrasonic propagation velocity and the velocity remains unchanged for two consecutive unit times, the inert gas pressure value is adjusted for the second time.

[0080] The inert gas pressure value after the second adjustment is Lb=La-(Vs1-Vs)×q3, where q3 is the compensation parameter for the influence of the difference between the first ultrasonic propagation velocity and the actual measured value of the ultrasonic propagation velocity on the inert gas pressure value after the second adjustment.

[0081] When the actual measured value of the ultrasonic wave propagation velocity after adjustment is greater than or equal to the preset first ultrasonic wave propagation velocity, the gas pressure value of the inert gas is not adjusted for the second time.

[0082] The inert gas pressure value is adjusted for a second time based on the comparison result between the actual measured value of the ultrasonic propagation velocity after the initial pressure of the inert gas is adjusted and the preset first ultrasonic propagation velocity, so as to avoid residual non-metallic impurities in the ladle. When the inert gas pressure is relatively high, the bubbles are relatively large, which can initially bring out the non-metallic impurities in the ladle. If the actual measured value of the ultrasonic propagation velocity after adjustment is less than the preset first ultrasonic propagation velocity and the velocity remains unchanged for two consecutive unit times, the inert gas pressure value is adjusted for a second time, so as to ensure that when the inert gas pressure decreases, the bubbles become smaller and rise more gently, so that the non-metallic impurities in the ladle can be brought out more evenly.

[0083] Specifically, an inert gas pressure evaluation value is generated according to the average existence time of the inert gas bubbles and the average diameter of the inert gas bubbles, and whether the remaining amount of non-metallic impurities in the ladle meets the standard is determined according to the inert gas pressure evaluation value.

[0084] Set the standard inert gas pressure evaluation value Fb,

[0085] The camera device measures the average existence time and average diameter of the inert gas bubbles.

[0086] The inert gas pressure evaluation value Fd=Tp×r1+Zp×r2, where Tp is the average existence time of the inert gas bubble; r1 is the compensation parameter for the influence of the average existence time of the inert gas bubble on the inert gas evaluation value; Zp is the average diameter of the inert gas bubble,

[0087] The average existence time of the inert gas bubbles is inversely proportional to the average diameter of the inert gas bubbles.

[0088] Tp=H / Zp, where H is the proportional constant,

[0089] When the remaining amount of non-metallic impurities in the ladle is greater than the preset standard remaining amount of non-metallic impurities, the inert gas bubble pressure is adjusted so that the inert gas pressure evaluation value Fd is within the range of [Fb, 1.2Fb].

[0090] When the impurity content in the ladle is greater than the preset standard non-metallic impurity residual amount, the inert gas bubble pressure value is adjusted to make the inert gas pressure evaluation value within the preset evaluation value range, so that the generated inert gas bubbles can be uniform and maintain a certain taking-out speed to effectively take out the non-metallic impurities, thereby avoiding residual non-metallic impurities mixed in the molten steel in the ladle and affecting the quality of the finished steel.

[0091] Specifically, the inert gas thermal evaluation value is generated based on the inert gas temperature and the inert gas pressure.

[0092] Specifically, the inert gas thermal evaluation value is adjusted according to the difference between the preset standard temperature in the ladle and the actual temperature in the ladle.

[0093] The inert gas thermal evaluation value Fb=Lb×z1+Yb×z2, wherein z1 is a compensation parameter for the influence of the inert gas pressure on the inert gas thermal evaluation value; Yb is the inert gas temperature; z2 is a compensation parameter for the influence of the inert gas temperature on the inert gas thermal evaluation value.

[0094] The preset standard temperature of the ladle is Y1, and the actual temperature in the ladle is Ys.

[0095] Set the temperature difference of the first ladle to Fb1 and the temperature difference of the second ladle to Fb2.

[0096] If the difference between the preset ladle standard temperature Y1 and the actual temperature Ys in the ladle is less than the first ladle temperature difference Fb1, the inert gas heat evaluation value is adjusted to 0.9Fb;

[0097] If the difference between the preset ladle standard temperature Y1 and the actual temperature Ys in the ladle is greater than or equal to the first ladle temperature difference Fb1 and less than or equal to the second ladle temperature difference Fb2, the inert gas belt heat evaluation value is not adjusted;

[0098] If the difference between the preset ladle standard temperature Y1 and the actual temperature Ys in the ladle is greater than the second ladle temperature difference Fb2, the inert gas heat evaluation value is adjusted to 1.2Fb.

[0099] When the difference between the preset standard ladle temperature and the actual temperature in the ladle is less than the first ladle temperature difference, the inert gas heat evaluation value is adjusted to a smaller value, which can ensure that the inert gas does not need to move violently when the temperature difference in the ladle is small, thereby reducing equipment loss; when the difference between the preset standard ladle temperature and the actual temperature in the ladle is greater than the second ladle temperature difference, the inert gas heat evaluation value is adjusted to a higher value, which can ensure that when the temperature difference in the ladle is large, the inert gas can pass through the ladle faster, thereby taking away excess heat faster, lowering the temperature, and improving the ladle cooling efficiency.

[0100] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0101] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A rare earth corrosion-resistant steel preparation process, characterized in that: include, Inert gas is introduced into the ladle to salvage the metal impurities in the ladle in stages; The metal impurity area collected by the image detection device is used to determine the position where the inert gas is introduced into the ladle based on the metal impurity area, and the inert gas flow rate is controlled according to the comparison result between the metal impurity area and the preset metal impurity area; Generate a metal impurity salvage volume change curve based on the metal impurity salvage volume and the metal impurity salvage time, and determine whether to start non-metallic impurity detection based on the change curve analysis results; When determining to conduct non-metallic impurity detection, the non-metallic impurity content in the ladle is detected by the propagation speed of ultrasonic waves in the ladle, and the inert gas pressure is adjusted according to the detection results; The inert gas heat evaluation value is adjusted according to the difference between the temperature in the ladle after impurities are removed and the standard temperature in the ladle; Generate an inert gas thermal evaluation value according to the inert gas temperature and the inert gas pressure; The inert gas heat evaluation value is adjusted according to the difference between the preset standard temperature in the ladle and the actual temperature in the ladle; The inert gas thermal evaluation value Fb=Lb×z1+Yb×z2, wherein Lb is the inert gas pressure value; z1 is the compensation parameter for the influence of the inert gas pressure on the inert gas thermal evaluation value; Yb is the inert gas temperature; and z2 is the compensation parameter for the influence of the inert gas temperature on the inert gas thermal evaluation value.

2. The process for preparing rare earth corrosion-resistant steel according to claim 1, characterized in that: The metal impurity salvaging stage is divided into the first salvaging stage and the second salvaging stage according to the metal impurity area in the ladle and the amount of metal impurities salvaged in the ladle.

3. The process for preparing rare earth corrosion-resistant steel according to claim 2, characterized in that: A metal impurity area change curve is generated according to the change of the metal impurity area per unit time in the first salvage stage, and it is determined whether to adjust the release rate of the inert gas at the bottom of the ladle according to the change of the slope of the metal impurity area change curve per unit time; and it is determined whether to open the inert gas port at the side of the ladle to stir the metal impurities according to the change of the slope of the metal impurity area change curve after the inert gas release rate is adjusted.

4. The process for preparing rare earth corrosion-resistant steel according to claim 3, characterized in that: The metal impurity salvage amount variation curve is generated according to the metal impurity salvage amount per unit time in the second salvage stage, and whether to start the detection of non-metallic impurities is determined according to the comparison result between the metal impurity salvage amount variation curve and the set standard metal impurity salvage amount.

5. The process for preparing rare earth corrosion-resistant steel according to claim 4, characterized in that: The ultrasonic propagation velocity of the ultrasonic wave passing through the ladle is measured by an ultrasonic velocity measuring device, and the non-metallic impurity content in the ladle is estimated based on the ultrasonic propagation velocity measurement result.

6. The process for preparing rare earth corrosion-resistant steel according to claim 5, characterized in that: The initial pressure value of the inert gas introduced into the ladle is adjusted by estimating the non-metallic impurity content in the ladle.

7. The process for preparing rare earth corrosion-resistant steel according to claim 6, characterized in that: Whether to perform secondary adjustment on the gas pressure value of the inert gas is determined based on the comparison result between the actual measured value of the ultrasonic wave propagation velocity after the initial pressure adjustment of the inert gas and the preset first ultrasonic wave propagation velocity.

8. The process for preparing rare earth corrosion-resistant steel according to claim 7, characterized in that: An inert gas pressure evaluation value is generated based on the average existence time of the inert gas bubbles and the average diameter of the inert gas bubbles. Based on the inert gas pressure evaluation value, it is determined whether the remaining amount of non-metallic impurities in the ladle meets the standards.

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