Patent Description:
During metal processing, rolling may be used to reduce a thickness of a metal substrate (such as stock sheets or strips of aluminum, aluminum alloys, or various other metals) by passing the metal substrate through a pair of work rolls. Depending on the desired properties of the final metal product, the metal stock may be hot rolled, cold rolled, and/or warm rolled. Hot rolling generally refers to a rolling process where the temperature of the metal is above the recrystallization temperature of the metal. Cold rolling generally refers to a rolling process where the temperature of the metal is below the recrystallization temperature of the metal. Warm rolling generally refers to a rolling process where the temperature of the metal is below the recrystallization temperature but above the temperature during cold rolling. However, the properties of the metal (e.g. strength, formability, corrosion resistance, and/or low weight, among others) after rolling may be insufficient for some applications (e.g., automotive, transportation, industrial, and/or electronics-related applications, among others). Therefore, further metal processing of the metal substrate is needed.

In <CIT>, top and bottom nozzles are operated until a metal substrate is cooled from an initial temperature to a predetermined temperature, then the top nozzles are deactivated, and the bottom nozzles are operated further to maintain this predetermined temperature.

In <CIT>, an upper surface of the metal substrate is cooled more than a lower surface of the metal substrate due to the cooling agent collecting on the upper surface. To reduce this effect, the distribution of the cooling agent is controlled in consideration of a limit temperature such that the temperature of the upper surface of the metal substrate, and, if appropriate, also of the lower surface, is not reduced any further.

The invention provides a system according to claim <NUM>, for processing a metal substrate, including but not limited to a rolled metal substrate, includes a quenching system. The quenching system includes a top nozzle configured to distribute a cooling agent on a top surface of the rolled metal substrate. The quenching system includes a bottom nozzle configured to distribute the cooling agent on a bottom surface of the rolled metal substrate. The top nozzle is configured to distribute the cooling agent until a strip temperature of the rolled metal substrate is reduced from an initial temperature to an intermediate temperature that is less than the initial temperature. The bottom nozzle is configured to distribute the cooling agent until the strip temperature of the rolled metal substrate is reduced from the initial temperature to a target temperature that is less than the initial temperature and less than the intermediate temperature.

The invention also provides a method according to claim <NUM>, of processing a rolled metal substrate includes cooling a top surface and a bottom surface of the rolled metal substrate with a quenching system such that a strip temperature of the rolled metal substrate is reduced from an initial temperature to an intermediate temperature. The method includes stopping the cooling of the top surface when the strip temperature is the intermediate temperature. The method includes continuing cooling the bottom surface of the rolled metal substrate with the quenching system such that the strip temperature of the rolled metal substrate is reduced from the intermediate temperature to a target temperature.

According to certain examples, the system for processing a rolled metal substrate includes the quenching system configured to selectively distribute a cooling agent on the metal substrate in a first quenching configuration and a second quenching configuration. In some aspects, the quenching system cools a top surface and a bottom surface of the metal substrate in the first quenching configuration and cools only the bottom surface of the metal substrate in the second quenching configuration. The system includes a sensor configured to detect a strip temperature of the metal substrate. In various aspects, the quenching system is in the first quenching configuration when the strip temperature is at least an intermediate temperature, and the quenching system is in the second quenching configuration when the strip temperature is reduced from the intermediate temperature to a target temperature that is less than the intermediate temperature.

Here, the method of processing a rolled metal substrate includes detecting a strip temperature of the rolled metal substrate, cooling a top surface and a bottom surface of the rolled metal substrate with a quenching system when the strip temperature is at least an intermediate temperature, and cooling only the bottom surface of the rolled metal substrate with the quenching system when the strip temperature decreases from the intermediate temperature to a target temperature that is less than the intermediate temperature.

Here, the system for processing a rolled metal substrate includes the quenching system. The quenching system includes at least one top nozzle configured to distribute a cooling agent on a top surface of the rolled metal substrate and at least two bottom nozzles configured to distribute the cooling agent on a bottom surface of the rolled metal substrate. The quenching system includes a first quench zone that includes the at least one top nozzle and a first bottom nozzle of the at least two bottom nozzles. The quenching system includes a second quench zone downstream from the first quench zone and including a second bottom nozzle of the at least two bottom nozzles.

The features and components of the following figures are illustrated to emphasize the general principles of the present disclosure. Corresponding features and components throughout the figures can be designated by matching reference characters for the sake of consistency and clarity.

Disclosed are systems and methods for quenching a metal substrate after rolling. Aspects and features of the present disclosure can be used with any suitable metal substrate, and may be especially useful with aluminum or aluminum alloys. Specifically, desirable results can be achieved for alloys such as 1xxx series, 2xxx series, 3xxx series, 4xxx series, 5xxx series, 6xxx series, 7xxx series, or 8xxx series aluminum alloys. For an understanding of the number designation system most commonly used in naming and identifying aluminum and its alloys, see "<NPL>" or "<NPL>.

In some cases, the systems and methods disclosed herein may be used with nonferrous materials, including aluminum, aluminum alloys, magnesium, magnesium-based materials, titanium, titanium-based materials, copper, copper-based materials, steel, steel-based materials, bronze, bronze-based materials, brass, brass-based materials, composites, sheets used in composites, or any other suitable metal, non-metal or combination of materials. The article may include monolithic materials, as well as non-monolithic materials such as roll-bonded materials, clad materials, composite materials (such as but not limited to carbon fiber-containing materials), or various other materials. In one non-limiting example, the systems and methods can be used with metal articles such as aluminum metal strips, slabs, shates, plates, or other articles made from aluminum alloys, including aluminum alloys containing iron.

Aspects and features of the present disclosure can be used to rapidly quench a metal substrate during metal processing from an initial temperature to a target temperature. Aspects and features of the present disclosure can also be used to control a flatness of the metal substrate. In some examples, aspects and features of the present disclosure can be used to rapidly quench a metal substrate after rolling of the metal substrate, such as after hot rolling of the metal substrate. In some non-limiting examples where the metal substrate includes aluminum or an aluminum alloy, rapid quenching of the metal substrate may lock in the elements to produce a finished aluminum alloy product with improved properties (e.g., improved strength, high corrosion resistance, high formability, etc.). As one non-limiting example, aspects and features of the present disclosure may be used to rapidly quench a 6xxx series aluminum alloy with solutes such as magnesium (Mg), silicon (Si), copper (Cu), zinc, (Zn), and/or various other solutes after hot rolling.

An example of a quenching system <NUM> for rapidly quenching a rolled metal substrate <NUM> is illustrated in <FIG>. In some examples, the metal substrate <NUM> is processed by a metal processing system <NUM> upstream from the quenching system <NUM>. As one non-limiting example, the metal substrate <NUM> may be rolled by a rolling mill <NUM> upstream from the quenching system <NUM>. After processing, the metal substrate <NUM> then passes through the quenching system <NUM>, which distributes a cooling agent on the metal substrate <NUM> to quench the metal substrate <NUM> and reduce the temperature of the metal substrate <NUM>. After passing through the quenching system <NUM>, the metal substrate <NUM> passes through a flatness-measuring device <NUM>, which determines a flatness profile of the metal substrate <NUM>. In some optional examples, the flatness-measuring device <NUM> provides a flatness signal <NUM> to a control system <NUM>. Based on the flatness signal <NUM>, the control system <NUM> may provide a quenching adjustment signal <NUM> to the quenching system <NUM> to control, and adjust as needed, the application of the cooling agent. Additionally or alternatively, the control system <NUM> may provide a rolling adjustment signal <NUM> to the rolling mill <NUM> to control, and adjust as needed, the rolling of the metal substrate <NUM>.

As discussed above, in some examples, the quenching system <NUM> may be provided with the metal processing system <NUM> that includes various equipment for processing the metal substrate <NUM> to a final product. As illustrated in <FIG>, in some examples, the metal processing system <NUM> includes at least one work stand <NUM> of the rolling mill <NUM>. In some examples, the rolling mill <NUM> includes a plurality of work stands <NUM>, such as two work stands <NUM>, three work stands <NUM>, four work stands <NUM>, or any other desired number of work stands <NUM>. The work stand <NUM> includes a pair of vertically aligned work rolls 118A-B. In some examples, the work stand <NUM> also includes backup rolls 120A-B that support the work rolls 118A-B. In various examples, the work stand <NUM> also includes intermediate rolls. A roll gap <NUM> is defined between the work rolls 118A-B.

During processing, the metal substrate <NUM> is moved in a processing direction <NUM> and is passed through the roll gap <NUM> such that the work rolls 118A-B reduce the thickness of the metal substrate <NUM> to a desired thickness and impart particular properties on the metal substrate <NUM>. The particular properties imparted may depend on the composition of the metal substrate <NUM>. In some examples, the rolling mill <NUM> may be a hot rolling mill that is configured to roll the metal substrate <NUM> when the temperature of the metal substrate <NUM> is above the recrystallization temperature of the metal substrate <NUM>. In some non-limiting examples, when the rolling mill <NUM> is a hot rolling mill, hot rolling of the metal substrate <NUM> may be performed at a temperature of from about <NUM> to about <NUM> (e.g., from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, etc.). In other examples, the rolling mill <NUM> may be a cold rolling mill that is configured to roll the metal substrate <NUM> when the temperature of the metal substrate <NUM> is below the recrystallization temperature of the metal substrate <NUM>. In various other examples, the rolling mill <NUM> may be a warm rolling mill that is configured to roll the metal substrate <NUM> when the temperature of the metal substrate <NUM> is below the recrystallization temperature but above the temperature during cold rolling.

In some examples, the quenching system <NUM> is provided downstream from the rolling mill <NUM> (or other processing equipment) to quench the metal substrate <NUM> after rolling (or other processing). As illustrated in <FIG>, the quenching system <NUM> includes at least one top nozzle 104A for distributing the cooling agent on a top surface <NUM> of the metal substrate <NUM>. In the present example, the quenching system <NUM> includes four top nozzles 104A. However, in various other examples, any number of top nozzles 104A may be provided, such as one top nozzle 104A, two top nozzles 104A, three top nozzles 104A, five top nozzles 104A, or more than five top nozzles 104A. The cooling agent may be any suitable cooling agent or cooling medium capable of sufficiently removing heat from the metal substrate <NUM> to generate the desired cooling. For example, the cooling agent may be water, an emulsion containing water, a mechanical dispersion containing water, a low-boiling temperature fluid, oil, or various other suitable cooling agents.

The quenching system <NUM> also includes at least one bottom nozzle 104B for distributing the cooling agent on a bottom surface <NUM> of the metal substrate <NUM>. In the present example, the quenching system <NUM> includes four bottom nozzles 104B. However, in various other examples, any number of bottom nozzles 104B may be provided, such as one bottom nozzle 104B, two bottom nozzles 104B, three bottom nozzles 104B, five bottom nozzles 104B, or more than five bottom nozzles 104B. In some examples, the number of bottom nozzles 104B is the same as the number of top nozzles 104A, although it need not be. For example, in other cases, the quenching system <NUM> may include additional or fewer bottom nozzles 104B compared to the number of top nozzles 104A (see, e.g., <FIG>).

In various examples, the top nozzles 104A and the bottom nozzles 104B are selectively controllable to cool the metal substrate <NUM> such that a strip temperature of the metal substrate <NUM> is reduced from an initial temperature to a target temperature. The initial temperature is the strip temperature when the metal substrate <NUM> is received by the quenching system <NUM>. In some examples, the initial temperature is the strip temperature of the metal substrate <NUM> after hot, warm or cold rolling. In certain non-limiting examples, the initial temperature may be greater than about <NUM>, such as greater than about <NUM>, although it need not be. In some examples, the initial temperature depends on the content of metal substrate <NUM>. The target temperature is the desired strip temperature of the metal substrate <NUM> after quenching. In certain examples, the target temperature may depend on the strip temperature requirements for additional processing or desired properties of the metal substrate <NUM>. In some non-limiting examples, the target temperature may be from about <NUM> to about <NUM>, although various other target temperatures less than the initial temperature may be used.

According to various examples, the top nozzles 104A and the bottom nozzles 104B are selectively controllable such that both the top nozzles 104A and the bottom nozzles 104B distribute the cooling agent to reduce the strip temperature from the initial temperature to an intermediate temperature. In various examples, the intermediate temperature is less than the initial temperature and greater than the target temperature. In some non-limiting examples, the intermediate temperature may be from about <NUM> to about <NUM>. In certain examples, the top nozzles 104A and the bottom nozzles 104B are selectively controllable such that the top nozzles 104A stop distributing the cooling agent when the strip temperature reaches the intermediate temperature (and thus stop cooling the metal substrate <NUM>) while the bottom nozzles 104B continue distributing the cooling agent such that the strip temperature is reduced from the intermediate temperature to the target temperature. In various examples, the portion of the quenching system <NUM> with activated top nozzles 104A and bottom nozzles 104B defines a first quench zone <NUM>, and the portion of the quenching system <NUM> with only the activated bottom nozzles 104B defines a second quench zone <NUM>.

In various examples, the top nozzles 104A and the bottom nozzles 104B are selectively controllable such that both the top nozzles 104A and the bottom nozzles 104B distribute the cooling agent to reduce the strip temperature from the initial temperature to the intermediate temperature. In certain examples, the top nozzles 104A and the bottom nozzles 104B are selectively controllable such that the bottom nozzles 104B stop distributing the cooling agent when the strip temperature reaches the intermediate temperature (and thus stop cooling the metal substrate <NUM>) while the top nozzles 104A continue distributing the cooling agent such that the strip temperature is reduced from the intermediate temperature to the target temperature. In other words, in certain non-limiting examples, both the top nozzles 104A and bottom nozzles 104B cool the strip to reduce the strip temperature from the initial temperature to the intermediate temperature, and one of the top nozzles 104A or the bottom nozzles 104B are deactivated when the strip temperature reaches the intermediate temperature such that the metal substrate <NUM> is only cooled from one side (i.e., on the top surface <NUM> or the bottom surface <NUM>).

In certain examples, the top nozzles 104A and/or the bottom nozzles 104B may distribute the cooling agent across a width <NUM> (see <FIG>) of the metal substrate <NUM> to uniformly cool the metal substrate <NUM> across the width <NUM>. In other examples, as illustrated in <FIG>, the top nozzles 104A and/or the bottom nozzles 104B may distribute the cooling agent across the width <NUM> of the metal substrate <NUM> to generate differential cooling, meaning that some portions of the metal substrate <NUM> may be cooled more than other portions of the metal substrate <NUM>. In various examples, some of the top nozzles 104A may provide uniform cooling across the width <NUM> and other top nozzles 104A may provide differential cooling. Likewise, in some examples, some of the bottom nozzles 104B may provide uniform cooling across the width <NUM> and other bottom nozzles 104B may provide differential cooling. In various examples, the amount and application of the cooling agent to particular locations along the width <NUM> of the metal substrate <NUM> can be adjusted based on a desired flatness profile.

<FIG> illustrates one non-limiting example of differential cooling where selected portions <NUM> of the metal substrate <NUM> are cooled and unselected portions <NUM> are not cooled or receive less cooling agent compared to the selected portions <NUM>. In certain examples, the selected portions <NUM> may be portions of the metal substrate <NUM> where the strip tension is the highest. As one non-limiting example, strip tension may be highest at edges <NUM> of the metal substrate <NUM>. The more localized the stress, the less differential cooling may be required to achieve the desired improved flatness. In some cases, a relatively small amount of cooling can be applied to the edges <NUM> of the metal substrate <NUM>, which can remove or reduce significant center buckles and/or distortion from the metal substrate <NUM>. Unselected portions <NUM> can be portions where the strip tension is lower, such as the middle of the metal substrate <NUM> between the edges <NUM>. Differential cooling includes any difference in temperature applied across the width <NUM> of the metal substrate <NUM>. In some examples, the selected portion <NUM> (e.g., an edge <NUM>) along the width <NUM> of the metal substrate <NUM> can be subjected to cooling while the unselected portion <NUM> (e.g., the middle of the metal substrate <NUM>) along the width <NUM> of the metal substrate <NUM> is not subjected to any cooling. In other examples, a selected portion <NUM> (e.g., an edge <NUM>) along the width <NUM> of the metal substrate <NUM> can be subjected to greater cooling than the cooling provided to the unselected portion <NUM> (e.g., the middle of the metal substrate <NUM>) along the width <NUM> of the metal substrate <NUM>.

Application of differential (also referred to as non-uniform, preferential, or selective) cooling to the selected portions <NUM> of the width <NUM> of a metal substrate <NUM> can cause the selected portions <NUM> to thermally contract, increasing the tension along the selected portions <NUM>. Differential cooling can cause a temporary temperature gradient along the metal substrate <NUM> where the selected portions <NUM> of the width <NUM> of the metal substrate <NUM> (e.g., the edges <NUM>) are cooler than the unselected portions <NUM> (e.g., the middle).

In the non-limiting example of <FIG> where cooling is applied to the edges <NUM> of the metal substrate <NUM> to generate the temperature gradient, the tension at the edges <NUM> of the metal substrate <NUM> can be temporarily increased, compared to the warmer, unselected portion <NUM> (e.g., middle) of the metal substrate <NUM>. Because the temperature along the width <NUM> of the metal substrate <NUM> is not uniform, differential tension exists along the width <NUM> of the metal substrate <NUM>. If this imposed tension distribution is not equalized soon after being applied (e.g., by intervening support rolls, or otherwise), and the metal substrate <NUM> is sufficiently hot to yield slightly under the differential tension, the differential temperature imparted by the differential cooling can cause the metal substrate <NUM> to lengthen slightly along the colder portion of the width <NUM> (e.g., the selected portions <NUM>) of the metal substrate <NUM>. Yield, as used herein, can be considered a permanent strain or elongation of the metal substrate <NUM>, which partially relieves the applied stress (e.g., from the imposed tension distribution). The stress required to cause permanent strain decreases as the metal substrate <NUM> temperature increases. As used herein with reference to metal substrate <NUM>, yield includes permanent strain at conventionally accepted yield stress levels, as well as at stress levels below the conventionally accepted yield stress levels, such as the permanent strain that can occur from rapid creep. Therefore, for a metal substrate <NUM> to yield, as the term is used herein, it is not necessary to induce differential tension that provides stress levels at or above the conventionally accepted yield stress of the metal substrate <NUM>.

Regardless of whether or not the actual temperature gradient imposed on the metal substrate <NUM> is known, the temperature gradient is based on the differential cooling, which can be based on various factors, such as models, flatness measurements, or other factors, as disclosed herein. Differential cooling of the edges <NUM> of a metal substrate <NUM> causes a local concentration of tensile stress sufficient to put the metal substrate <NUM> into yield and stretch the edges <NUM>, correcting any center waves or distortion present in the metal substrate <NUM>. In this way, the flatness of the metal substrate <NUM> can be adjusted and/or improved using differential cooling. When active differential cooling of the metal substrate <NUM> is discontinued, the temperature profile of the metal substrate <NUM> across its width <NUM> will eventually equalize, but any changes due to yield will remain, and therefore the improved flatness will be maintained. As described below, in certain examples, the flatness-measuring device <NUM> is positioned a predetermined distance <NUM> downstream from the quenching system <NUM> that is sufficient for the temperature profile to equalize.

As illustrated in <FIG>, in certain examples, a sensor <NUM> may be provided to detect the strip temperature. The location or number of sensors <NUM> should not be considered limiting on the current disclosure.

In some examples, a coolant removal device <NUM> or other coolant containment system may be provided. In various examples, the coolant removal device <NUM> may be provided for removing the cooling agent off the top surface <NUM> of the metal substrate <NUM>, the bottom surface <NUM> of the metal substrate <NUM>, or both the top surface <NUM> and the bottom surface <NUM> of the metal substrate <NUM>. As such, the number and location of the coolant removal devices <NUM> should not be considered limiting on the current disclosure. In various examples, the coolant removal device <NUM> may be any device suitable for removing the cooling agent off the metal substrate <NUM> including, but not limited to, a blower, a wiper, a flexible seal, or various other suitable devices. In one non-limiting example, the coolant removal device <NUM> is a blower that is an air knife. As described below, in various aspects, the coolant removal device <NUM> may be activated when the top nozzles 104A stop distributing the cooling agent on the metal substrate (i.e., when the strip temperature reaches the intermediate temperature) to remove residual cooling agent off the top surface <NUM> of the metal substrate <NUM>.

In various examples, the flatness-measuring device <NUM> is provided to measure the flatness profile of the metal substrate <NUM>. In some non-limiting examples, the flatness-measuring device <NUM> is a shape roll, although various other suitable devices for detecting the flatness profile of the metal substrate <NUM> may be used. The flatness-measuring device <NUM> is positioned the predetermined distance <NUM> downstream from the quenching system <NUM>. The predetermined distance <NUM> between the flatness-measuring device <NUM> and the quenching system <NUM> is a distance that allows for a temperature profile across the width <NUM> of the metal substrate <NUM> to equalize. In some cases, by providing the predetermined distance <NUM> before measuring the flatness profile with the flatness-measuring device, a more accurate shape measurement (e.g., flatness profile) may be obtained because temperature variations across the width <NUM> (which would otherwise cause inaccurate measurements) are minimized or reduced. In certain examples, at least one aspect of the quenching system <NUM> is adjustable or controllable based on the measured flatness profile. In some non-limiting examples, the at least one aspect of the quenching system <NUM> may include a number of activated top nozzles 104A and/or the bottom nozzles 104B, the cooling profile of the top nozzles 104A and/or the bottom nozzles 104B, an amount of cooling agent distributed by the top nozzles 104A and/or the bottom nozzles 104B, and/or various other adjustable aspects of the quenching system <NUM>. In some examples, at least one aspect of the rolling mill <NUM> is controllable or adjustable based on the measured flatness profile including, but not limited to, a size of the roll gap <NUM>, a contact pressure distribution of the work rolls 118A-B on the metal substrate <NUM>, and/or various other adjustable aspects of the rolling mill <NUM>.

Optionally, the control system <NUM> is provided. As illustrated in <FIG>, the control system <NUM> may be in communication with the flatness-measuring device <NUM> and the quenching system <NUM>. In some optional cases, the control system <NUM> is also in communication with the work stand <NUM>. The control system <NUM> is configured to receive the flatness profile measured by the flatness-measuring device <NUM> as part of the flatness signal <NUM>. The control system <NUM> is further configured to compare the measured flatness profile to a predetermined flatness profile. Based on the comparison of the measured flatness profile to the predetermined flatness profile, the control system <NUM> may control, and adjust as needed, the quenching system <NUM> and/or the work stand <NUM> such that the measured flatness profile matches the predetermined flatness profile. As one non-limiting example, <FIG> illustrates a case where additional rapid quenching is needed (e.g., because the strip temperature is too high), and additional top nozzles 104A are activated. As another non-limiting example, <FIG> illustrates a case where less quenching is needed (e.g., because the strip temperature is sufficiently low), and additional top nozzles 104A are deactivated.

<FIG> illustrates an example of a quenching system <NUM> that is substantially similar to the quenching system <NUM> except that the second quench zone <NUM> only includes the bottom nozzles 104B.

A method of processing the metal substrate <NUM> is also provided. In various examples, the method includes receiving the metal substrate <NUM> having the strip temperature at the initial strip temperature at the quenching system <NUM>. In some examples, the method includes rolling the metal substrate <NUM> with the rolling mill <NUM> prior to receiving the metal substrate <NUM> at the quenching system <NUM>. In one non-limiting example, the method includes hot rolling the metal substrate <NUM> before receiving the metal substrate <NUM> at the quenching system <NUM>.

The method includes quenching the metal substrate <NUM> with the quenching system <NUM>. Quenching includes cooling the top surface <NUM> and the bottom surface <NUM> of the metal substrate <NUM> with the quenching system <NUM> such that the strip temperature is reduced from the initial temperature to the intermediate temperature. In some aspects, cooling the top surface <NUM> includes distributing the cooling agent on the top surface <NUM> with at least one top nozzle 104A, and cooling the bottom surface <NUM> includes distributing the cooling agent on the bottom surface <NUM> with at least one bottom nozzle 104B.

In various aspects, the method includes detecting the strip temperature of the metal substrate <NUM> with the sensor <NUM>. In some examples, quenching includes using the top nozzles 104A to distribute the cooling agent onto the top surface <NUM> of the metal substrate <NUM> until a strip temperature of the metal substrate is reduced from an initial temperature to an intermediate temperature. In various examples, the quenching includes using the bottom nozzles 104B to distribute the cooling agent on the bottom surface <NUM> until the strip temperature of the metal substrate is reduced from the initial temperature to a target temperature, which is less than the intermediate temperature. In other words, quenching the metal substrate <NUM> with the quenching system <NUM> includes cooling both the top surface <NUM> and the bottom surface <NUM> of the metal substrate <NUM> until the strip temperature is reduced from the initial temperature to the intermediate temperature and stopping the cooling of the top surface <NUM> while continuing the cooling of the bottom surface <NUM> such that the strip temperature is reduced from the intermediate temperature to the target temperature. In certain aspects, the method includes deactivating the quenching system <NUM> such that the quenching system <NUM> stops cooling the metal substrate <NUM> when the strip temperature is at or below the target temperature.

According to various examples, cooling the top surface <NUM> may include cooling the selected portion <NUM> of the width <NUM> of the metal substrate <NUM> more than the unselected portion <NUM> of the width <NUM> of the metal substrate <NUM> with the top nozzles 104A. Similarly, in additional or alternative cases, cooling the bottom surface <NUM> may include cooling the selected portion <NUM> of the width <NUM> of the metal substrate <NUM> more than the unselected portion <NUM> of the width <NUM> of the metal substrate <NUM> with the bottom nozzles 104B. In various cases, the selected portion <NUM> is edges <NUM> of the metal substrate <NUM> and the unselected portion <NUM> is a non-edge portion (e.g., middle) of the metal substrate <NUM>.

In various cases, the method includes blowing residual cooling agent off the top surface <NUM> of the metal substrate <NUM> when the cooling of the top surface <NUM> is stopped. In some aspects, the method includes blowing residual cooling agent off the top surface <NUM> of the metal substrate <NUM> when the strip temperature reaches the intermediate temperature. In certain cases, the method includes blowing residual cooling agent off the top surface <NUM> of the metal substrate <NUM> while continuing the cooling of the bottom surface <NUM> of the metal substrate <NUM>.

According to certain examples, the method includes passing the metal substrate <NUM> from the quenching system <NUM> to the flatness-measuring device <NUM> after the predetermined distance <NUM>. In certain examples, passing the metal substrate <NUM> after the predetermined distance includes allowing a temperature profile across the width <NUM> of the metal substrate <NUM> to equalize. In various examples, passing the metal substrate <NUM> after the predetermined distance includes drying the bottom surface <NUM> of the metal substrate <NUM>, which may be blowing the bottom surface <NUM> or otherwise.

Claim 1:
A system for processing a metal substrate comprising:
a quenching system (<NUM>) comprising:
a top nozzle (104A) configured to distribute a cooling agent on a top surface (<NUM>) of the metal substrate (<NUM>);
a bottom nozzle (104B) configured to distribute the cooling agent on a bottom surface of the metal substrate (<NUM>), and
a flatness-measuring device (<NUM>) located a predetermined distance downstream from the quenching system (<NUM>), wherein the predetermined distance is a distance sufficient for the strip temperature to equilibrate, and wherein the flatness-measuring device (<NUM>) is configured to:
measure a flatness profile of the metal substrate (<NUM>) across a width of the metal substrate; and
output the measured flatness profile in a flatness signal, and
wherein the system further comprises a controller (<NUM>) configured to:
receive the flatness signal from the flatness-measuring device (<NUM>);
compare the measured flatness profile to a predetermined flatness profile; and
control the quenching system (<NUM>) such that the measured flatness profile matches the predetermined flatness profile,
wherein the top nozzle (104A) is configured to stop distributing the cooling agent when a strip temperature of the metal substrate (<NUM>) is reduced from an initial temperature to an intermediate temperature that is less than the initial temperature, and
wherein the bottom nozzle (104B) is configured to continue distributing the cooling agent until the strip temperature of the metal substrate (<NUM>) is reduced from the initial temperature to a target temperature that is less than the initial temperature and less than the intermediate temperature,
characterized by a coolant removal device (<NUM>) to be activated for removing residual cooling agent off the top surface of the metal substrate (<NUM>) when the top nozzle (104A) stops distributing the cooling agent on the metal substrate (<NUM>), wherein the intermediate temperature is from about <NUM> to about <NUM>, wherein the target temperature is from about <NUM> to about <NUM>, and wherein the initial temperature is greater than about <NUM>.