A method for rapid detection and rhythm control of hydrogen content of continuous casting tundish molten steel

Abstract

The present application belongs to the technical field of steelmaking continuous casting, and discloses a method for rapid detection and rhythm control of hydrogen content of molten steel in a continuous casting tundish, which comprises the following steps: step A, verifying the operation readiness of a hydrogen determination system to make it in a state of being ready for detection; step B, after a ladle is opened to the tundish, observing whether a blue flame is generated on the upper layer of the crystallizer protective slag to determine the hydrogen content level of the current molten steel; step C, when the corresponding flow triggers a sticking type breakout prediction alarm and causes a stop, controlling the speed of the blank drawing to restore the speed under preset conditions, and when the cumulative number of sticking alarm stops reaches a preset threshold, performing protective slag replacement and using the hydrogen determination system to measure the hydrogen content of the molten steel in the tundish, and feeding the result to the upstream steelmaking process and the production scheduling system. The method can realize rapid identification and timely intervention of the hydrogen content of the molten steel in the pouring process, and effectively reduce the sticking alarm stop rate and the breakout accident risk.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of continuous casting of steel, and particularly relates to a method for rapid detection and rhythm control of hydrogen content in molten steel in a continuous casting tundish. BACKGROUND

[0002] In slab continuous casting production, the tundish is a key transition container connecting the upstream steelmaking process (such as converter or electric furnace tapping) and the crystallizer, and bears the important functions of flow stabilization, flow distribution and purification of molten steel. After the molten steel is poured from the ladle into the crystallizer through the tundish, it gradually solidifies to form a shell under the action of water-cooled copper plates, and is finally continuously drawn out to form a slab. In this process, the dissolved gas in the molten steel, especially hydrogen, has an important influence on the quality of the cast slab and production safety.

[0003] The hydrogen in the molten steel mainly comes from the following three ways: first, in the process of steel tapping and refining, the crystal water or adsorbed water contained in the auxiliary materials such as lime and fluorite used in the desulfurization process of slag washing decomposes at high temperature, releases water vapor and reacts with the molten steel to generate dissolved hydrogen; second, in the process of pouring, due to the high humidity of the ambient air, the auxiliary materials (such as protective slag, covering agent, etc.) exposed to the air absorb water from the air, and when these water-containing auxiliary materials are added to the tundish or crystallizer, the water decomposes at high temperature, resulting in an increase in hydrogen in the molten steel; third, when the refractory lining of the ladle and the tundish is not fully roasted, the residual water will also become a source of hydrogen in the molten steel.

[0004] The solubility of hydrogen in molten steel increases with increasing temperature, while in the solidification process of molten steel, the solubility of hydrogen decreases sharply. When high-hydrogen molten steel enters the crystallizer, the dissolved hydrogen is precipitated from the steel lattice before solidification. Especially in the air gap area between the shell and the copper plate of the crystallizer, the temperature gradient is large and the supersaturation of hydrogen is high, and the precipitated hydrogen gas is easy to accumulate in the air gap. The accumulated hydrogen gas will have an adverse effect on the protective slag film in this area, which is manifested as follows: the presence of hydrogen changes the gas composition of the protective slag, reduces the lubricating property of the protective slag, and increases the friction between the shell and the copper plate; at the same time, the accumulation of hydrogen gas also hinders the heat conduction of the shell to the copper plate, resulting in local temperature rise and thickness thinning of the shell. When the shell strength is insufficient to resist the drawing resistance, sticking will occur on the inner wall of the crystallizer.

[0005] Adhesion is one of the most common forms of billet shell defects in continuous casting molds. Once adhesion occurs, the thermocouples on the copper plate of the mold will detect localized temperature anomalies, triggering an alarm in the leakage warning system and causing the production line to stop automatically. Frequent adhesion alarms and shutdowns not only disrupt the normal billet pulling rhythm and increase the labor intensity of operators, but in severe cases, they can also cause the billet shell to tear at the adhesion point, leading to leakage accidents. Leakage is one of the most serious accidents in continuous casting production, causing severe damage to the mold and the equipment below, resulting in prolonged production interruptions, disrupting the material flow balance at the iron-steel interface, and causing huge economic losses.

[0006] Currently, the industry primarily relies on offline measurements using hydrogen analyzers to detect the hydrogen content in molten steel. Hydrogen analyzers measure the dissolved hydrogen content by inserting a probe into the molten steel, utilizing specific electrochemical or thermal conductivity principles. While this method offers high accuracy, it suffers from several drawbacks: First, the testing cost is high, as disposable probes are consumables, and frequent use significantly increases production costs. Second, the testing process requires manual operation, including probe installation, probe insertion, and reading recording, increasing the workload for operators. Third, the time required from detecting an anomaly to completing the test makes high-frequency, rapid response difficult in the fast-paced production of steel casting. Fourth, hydrogen analyzer testing is a post-confirmation method and cannot predict the hydrogen content level of molten steel in real time during casting. Summary of the Invention

[0007] In view of this, the purpose of this invention is to solve the above problems and provide a rapid detection and rhythm control method for hydrogen content in molten steel in a continuous casting tundish.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A rapid detection and rhythm control method for hydrogen content in molten steel in a continuous casting tundish includes the following steps: Step A, preparation steps for the hydrogen determination system: perform operational readiness verification on the hydrogen determination system to put the hydrogen determination system into a test-ready state; Step B, monitoring steps of the pouring process: After the ladle starts pouring into the tundish, observe whether a blue flame is produced on the upper layer of the protective slag inside the crystallizer to determine the hydrogen content level of the current heat of molten steel. Step C, rhythm control step: When the current heat corresponding to the flow triggers a sticking-type steel leakage prediction alarm and causes a shutdown, the billet pulling speed is controlled to resume speed increase under preset conditions; when the cumulative number of sticking alarm shutdowns for the current heat corresponding to the flow reaches a preset threshold, the protective slag replacement operation is performed, and at the same time, the hydrogen content of the molten steel in the tundish is measured using the hydrogen control system, and the measurement results are fed back to the upstream steelmaking process for hydrogen control adjustment, and the production rhythm is coordinated with the production scheduling system.

[0009] Furthermore, in step A, the operational readiness verification of the hydrogen determination system includes: Check whether the nozzle of the hydrogen determination gun is deformed and whether it is clean and free of foreign objects. Check the degree of discoloration of the desiccant in the hydrogen determination filter. If the discoloration ratio exceeds the preset ratio, replace the hydrogen determination filter. Turn on the carrier gas supply device, adjust the outlet pressure to 0.45-0.5MPa and keep it stable; After opening all valves in the hydrogen control system, check the airtightness of the carrier gas pipeline and all joints to confirm that there are no leaks. After installing the hydrogen-determining paper tube at the front end of the hydrogen-determining gun, perform an air baseline measurement. Only after confirming that the measurement system has no deviation can it be put into use.

[0010] Furthermore, prior to step B, the process includes: the upstream steelmaking process determining, during tapping, the heats in which the hydrogen content in the molten steel may be ≥7ppm, and reporting this determination information to the continuous casting process.

[0011] Furthermore, in step B, before observing the inside of the crystallizer, the following steps are also included: checking that the immersion nozzle is vertically aligned with the impact zone of the tundish, confirming that the immersion depth meets the process requirements, and that there is no tumbling of the molten steel.

[0012] Furthermore, in step B, observing the blue flame specifically involves: observing whether there is a blue flame generated on the upper layer of the protective slag in both sides of the crystallizer. The presence of a blue flame indicates that the hydrogen content of the molten steel in the current furnace is high; at the same time, emergency preparations are made for sticking alarm shutdown, and the tundish liquid level control personnel are notified to perform precise flow control.

[0013] Furthermore, the control of the billet pulling speed to restore the acceleration under preset conditions specifically involves: After the adhesion alarm stops, the starting speed is controlled until the stop joint is removed from the bottom of the crystallizer before the speed-up operation is performed; When accelerating, increase the speed by 0.15-0.2 m / min at 10-second intervals, and maintain the speed at 1.0 m / min without further acceleration.

[0014] Furthermore, after accelerating to 1.0 m / min, the process also includes: confirming that the steel leakage prediction curve is stable and the liquid level fluctuation is ≤ ±5 mm, and then re-engaging in automatic liquid level control.

[0015] Furthermore, the preset threshold is 3 times.

[0016] Furthermore, the actual measurement of hydrogen content in molten steel from the tundish using a hydrogen determination system specifically includes: Install the disposable hydrogen determination probe on the front end of the probe and lock it. After the "Ready" indicator light on the main unit of the hydrogen determination instrument is lit, insert the probe vertically into the steady flow zone of the molten steel in the tundish to a depth of 300-400 mm. Once the hydrogen content value appears on the display screen, immediately remove the testing gun; The measured results are fed back to the upstream steelmaking process as follows: it is determined whether the hydrogen content in the molten steel at time t is ≥7.0ppm. The results are then fed back to the upstream steelmaking process for hydrogen control adjustments, and simultaneously fed back to the production scheduling system to coordinate the production rhythm.

[0017] Furthermore, the rhythm control steps also include: increasing the casting speed to the typical casting speed 5 minutes after casting begins in the furnace, and then restoring the normal cycle casting speed.

[0018] The beneficial effects of this invention are as follows: The rapid detection and rhythm control method for hydrogen content in molten steel in continuous casting tundish provided by this invention organically integrates online observation, rhythm control, and rapid hydrogen determination, forming a systematic solution for high-hydrogen molten steel pouring. Its beneficial effects are reflected in the following aspects: I. Rapid Identification of Hydrogen Content in Molten Steel During Casting. This invention utilizes the blue flame phenomenon produced when high-hydrogen molten steel burns in the crystallizer as an online criterion, allowing operators to determine the hydrogen content level of the molten steel in real time during casting without relying on expensive hydrogen analyzers. This identification method requires no additional equipment investment, is simple to operate, and responds quickly, overcoming the shortcomings of existing hydrogen analyzers, such as high detection cost, complex operation, and long response time. It achieves real-time and rapid prediction of hydrogen content in molten steel during casting.

[0019] II. Effectively Reduces the Occurrence Rate of Adhesion Alarm Shutdowns. This invention, by immediately initiating precise flow control preparation upon detecting high-hydrogen molten steel, employs a segmented, speed-limited ramp-up rhythm control strategy after an adhesion alarm shutdown (increasing speed by 0.15-0.2 m / min every 10 seconds, up to 1.0 m / min each time), avoiding the risk of secondary adhesion of the billet shell due to rapid speed increases. Simultaneously, automatic liquid level control is only resumed after the leakage prediction curve stabilizes and the liquid level fluctuation is ≤±5 mm, ensuring the stability of the billet shell solidification process. Through these measures, the adhesion shutdown rate is gradually reduced from 0.104 times / heat to <0.06 times / heat, and the number of alarms and shutdowns caused by adhesion per heat can be controlled to 3 times or less, significantly reducing the frequency of adhesion alarm shutdowns and lowering the workload of operators.

[0020] Third, it significantly reduces the risk of steel sticking and leakage accidents. This invention establishes a threshold control mechanism that triggers a protective slag replacement operation and actual hydrogen content measurement after ≥3 alarm shutdowns, preventing the prolonged maintenance of an unstable casting state under high hydrogen conditions. When the measured hydrogen content is confirmed to be ≥7.0 ppm, a feedback mechanism prompts upstream steelmaking processes to adjust hydrogen control, reducing the probability of high-hydrogen molten steel entering the crystallizer from the source. This significantly reduces the risk of steel sticking and leakage due to excessive hydrogen content, ensuring equipment and production safety.

[0021] IV. Ensuring Smooth Production at the Iron-Steel and Steel-Rolling Interfaces. This invention establishes a closed-loop information transmission mechanism across processes by feeding back hydrogen content determination results to the upstream steelmaking process in real time and coordinating production rhythm through the production scheduling system. The upstream steelmaking process can promptly adjust steel tapping operations and auxiliary material management based on hydrogen content feedback, controlling hydrogen content from the source; the production scheduling system can comprehensively arrange production plans based on actual hydrogen content levels, avoiding prolonged production interruptions due to steel leakage accidents. This mechanism effectively ensures the logistical balance at the iron-steel and steel-rolling interfaces, guaranteeing smooth production throughout the entire process.

[0022] V. Improving the Reliability and Measurement Accuracy of the Hydrogen Determination System. This invention systematically verifies the operational readiness of the hydrogen determination gun head, the desiccant status in the hydrogen determination filter, and the airtightness of the carrier gas pipeline during the preparation phase of the hydrogen determination system. Furthermore, it eliminates system deviations through air baseline measurements, ensuring that the hydrogen determination system is in a reliable, ready-to-test state when put into use. This avoids measurement errors caused by poor equipment condition, improves the reliability of the measured hydrogen content data, and provides accurate data support for production decisions.

[0023] VI. Reduced testing costs and labor intensity. Compared with the frequent testing relying on a hydrogen analyzer throughout the entire process, this invention uses blue flame observation as a preliminary screening method, and only starts the hydrogen analyzer for actual testing when the cumulative number of alarm shutdowns reaches a preset threshold. This significantly reduces the consumption of hydrogen analyzer probes and the frequency of hydrogen analyzer operation, effectively reducing testing costs and the labor intensity of operators while ensuring testing accuracy.

[0024] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is a flowchart illustrating the rapid detection and rhythm control method for hydrogen content in molten steel in a continuous casting tundish according to the present invention. Detailed Implementation

[0026] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0027] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0028] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and 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. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0029] Example 1 The hydrogen determination system involved in this invention includes a hydrogen determination gun, a hydrogen determination filter, a carrier gas supply device (including a gas cylinder and a pressure reducing valve), a hydrogen determination paper tube, a hydrogen determination instrument, a disposable hydrogen determination probe, and a measuring gun. The hydrogen determination gun is used to install the hydrogen determination paper tube for system preparation and baseline measurement; the hydrogen determination filter is installed in the carrier gas pipeline and contains a desiccant (such as silica gel) to remove moisture from the pipeline; the desiccant needs to be replaced when its color changes beyond a preset proportion (e.g., 2 / 3); the carrier gas supply device provides a stable pressure carrier gas (such as nitrogen) to the hydrogen determination system through a pressure reducing valve; the hydrogen determination instrument includes a main unit and an operation box, with "Measure," "Complete," and "Ready" indicator lights on the main unit and a "Start" button on the operation box; the disposable hydrogen determination probe is installed at the front end of the measuring gun and is used to insert into the molten steel in the tundish to measure the hydrogen content.

[0030] During the casting process of a slab continuous casting machine, such as Figure 1 As shown, the method of this invention is used for rapid detection and rhythm control of hydrogen content in molten steel. The specific operation is as follows: Step A: Preparation of the hydrogen determination system (1) Check that the nozzle of the hydrogen lance is not deformed and is clean and free of foreign objects; (2) Check the constant hydrogen filter. It was found that the desiccant (silica gel) had not changed color by more than 2 / 3. The filter was in normal condition and did not need to be replaced. (3) Open the switch valve of the carrier gas supply device (nitrogen cylinder), then open the pressure reducing valve and adjust the outlet pressure to 0.48MPa. The pressure is stable. (4) After opening all valves of the hydrogen control system, check the airtightness of the carrier gas pipeline and all joints in sequence to confirm that there is no leakage; (5) Install the hydrogen-determining paper tube at the front end of the hydrogen-determining gun; (6) Once the conditions for hydrogen determination are met, remove the hydrogen determination paper tube, perform an air baseline measurement, and confirm that the measurement system has no deviation. The hydrogen determination system can then be put into use.

[0031] Information notification before step B: When the upstream steelmaking process (converter) determines that the hydrogen content in the molten steel of this heat may be ≥7ppm, it notifies the continuous casting process of this determination.

[0032] Step B: Monitoring the pouring process (1) After pouring from the ladle to the tundish, check and confirm that the submerged nozzle is vertically aligned with the impact zone of the tundish, the immersion depth meets the process requirements, and there is no tumbling of molten steel. (2) The operator observed a blue flame on the protective slag layer in the southern area of ​​the crystallizer, indicating that the hydrogen content of the molten steel in the current furnace was high. The operator made emergency preparations for the sticking alarm shutdown, and at the same time notified the tundish liquid level control personnel to implement precise flow control; (3) The current furnace corresponds to the first sticking alarm and shutdown, and start step C.

[0033] Step C: Rhythm Control (1) After the adhesion alarm stops, control the starting speed until the stop joint is removed from the bottom of the crystallizer, and then perform the speed increase operation; (2) The throwing speed is increased by 0.15 m / min every 10 s interval, and after reaching 1.0 m / min, the speed is maintained and no further increase is made; (3) After the speed is increased to 1.0 m / min, confirm that the steel leakage prediction curve is stable and the liquid level fluctuation is ±3 mm (≤ ±5 mm), and put the automatic liquid level control back into operation; (4) After the current furnace batch has accumulated 3 adhesion alarm shutdowns (reaching the preset threshold), the protective slag replacement operation will be performed; (5) Use the hydrogen determination system to measure the hydrogen content of molten steel in the tundish: Install the disposable hydrogen determination probe on the front end of the test gun and lock it. Press the "Start" button on the hydrogen determination instrument operation box. After the "Measure" and "Complete" indicator lights on the main unit box of the hydrogen determination instrument are turned off and the "Ready" indicator light is lit, insert the test gun vertically into the steady flow zone of the molten steel in the tundish to a depth of 350mm. (6) Once the hydrogen content value of 8.2 ppm appears on the display screen, immediately remove the test gun; (7) Determine that the hydrogen content in the molten steel at time t is 8.2 ppm (≥7.0 ppm), and feed the determination result back to the upstream steelmaking process for hydrogen control adjustment, and at the same time feed it back to the production scheduling system to coordinate the production rhythm; (8) After casting for 5 minutes, increase the casting speed to the typical casting speed and restore the normal cycle casting speed.

[0034] By implementing this method, under high-hydrogen furnace conditions, the number of sticking alarm shutdowns per furnace was controlled to within 3, no steel leakage accidents occurred, and the sticking shutdown rate was reduced to <0.06 times / furnace, achieving safe and stable casting process.

[0035] During the casting process of another slab continuous casting machine, the upstream steelmaking process did not provide advance warning of hydrogen content. The operators did not observe blue flames on the upper layer of the mold flux during the casting process, and judged that the hydrogen content of the molten steel in the current heat was at a normal level. The casting was organized according to the normal process system, and the casting process was stable without triggering the adhesion alarm.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A rapid detection and rhythm control method for hydrogen content in molten steel in a continuous casting tundish, characterized in that, Includes the following steps: Step A, preparation steps for the hydrogen determination system: perform operational readiness verification on the hydrogen determination system to put the hydrogen determination system into a test-ready state; Step B, monitoring steps of the pouring process: After the ladle starts pouring into the tundish, observe whether a blue flame is produced on the upper layer of the protective slag inside the crystallizer to determine the hydrogen content level of the current heat of molten steel. Step C, rhythm control step: When the current furnace corresponding to the flow triggers a sticky leakage warning alarm and causes a shutdown, control the billet pulling speed to resume speed increase under preset conditions; When the cumulative number of sticking alarm shutdowns for the current heat reaches a preset threshold, a protective slag replacement operation is performed. At the same time, the hydrogen content of the molten steel in the tundish is measured using the hydrogen control system. The measured results are fed back to the upstream steelmaking process for hydrogen control adjustment, and the production rhythm is coordinated with the production scheduling system.

2. The method according to claim 1, characterized in that, Step A, the operational readiness verification of the hydrogen determination system includes: Check whether the nozzle of the hydrogen determination gun is deformed and whether it is clean and free of foreign objects. Check the degree of discoloration of the desiccant in the hydrogen determination filter. If the discoloration ratio exceeds the preset ratio, replace the hydrogen determination filter. Turn on the carrier gas supply device, adjust the outlet pressure to 0.45-0.5MPa and keep it stable; After opening all valves in the hydrogen control system, check the airtightness of the carrier gas pipeline and all joints to confirm that there are no leaks. After installing the hydrogen-determining paper tube at the front end of the hydrogen-determining gun, perform an air baseline measurement. Only after confirming that the measurement system has no deviation can it be put into use.

3. The method according to claim 1, characterized in that, Before step B, the process also includes: the upstream steelmaking process determining, during tapping, the heats in which the hydrogen content in the molten steel may be ≥7ppm, and reporting this determination information to the continuous casting process.

4. The method according to claim 1, characterized in that, Step B, before observing the inside of the crystallizer, also includes: checking that the immersion nozzle is vertically aligned with the tundish impact zone, confirming that the immersion depth meets the process requirements, and that there is no tumbling of molten steel.

5. The method according to claim 1, characterized in that, In step B, observing the blue flame specifically involves: observing whether there is a blue flame generated on the upper layer of the protective slag in both sides of the crystallizer. The presence of a blue flame indicates that the hydrogen content of the molten steel in the current furnace is high. At the same time, emergency preparations are made for sticking alarm shutdown, and the tundish liquid level control personnel are notified to perform precise flow control.

6. The method according to claim 1, characterized in that, The specific steps for controlling the billet pulling speed to recover and accelerate under preset conditions are as follows: After the adhesion alarm stops, the starting speed is controlled until the stop joint is removed from the bottom of the crystallizer before the speed-up operation is performed; When accelerating, increase the speed by 0.15-0.2 m / min at 10-second intervals, and maintain the speed at 1.0 m / min without further acceleration.

7. The method according to claim 6, characterized in that, After the speed is increased to 1.0 m / min, the process also includes: confirming that the steel leakage prediction curve is stable and the liquid level fluctuation is ≤ ±5 mm, and then re-engaging in automatic liquid level control.

8. The method according to claim 1, characterized in that, The preset threshold is 3 times.

9. The method according to claim 1 or 8, characterized in that, The specific steps for measuring the hydrogen content of molten steel in the tundish using a hydrogen determination system include: Install the disposable hydrogen determination probe on the front end of the probe and lock it. After the "Ready" indicator light on the main unit of the hydrogen determination instrument is lit, insert the probe vertically into the steady flow zone of the molten steel in the tundish to a depth of 300~400mm. Once the hydrogen content value appears on the display screen, immediately remove the testing gun; The measured results are fed back to the upstream steelmaking process as follows: it is determined whether the hydrogen content in the molten steel at time t is ≥7.0ppm. The results are then fed back to the upstream steelmaking process for hydrogen control adjustments, and simultaneously fed back to the production scheduling system to coordinate the production rhythm.

10. The method according to claim 1, characterized in that, The rhythm control steps also include: after pouring for 5 minutes in the furnace, increasing the casting speed to the typical casting speed and restoring the normal cycle casting speed.

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