JP5457770B2 - Steel plate heat treatment method and apparatus - Google Patents

Description

  The present invention relates to the steel sheet while relatively moving the steel sheet and the inductor in the longitudinal direction of the steel sheet for the grain refinement process performed by repeatedly performing a heat treatment applying rapid heating and subsequent quenching to the steel sheet. More specifically, a steel plate heat treatment method and a steel plate heat treatment apparatus that sequentially apply induction heating and subsequent quenching. In particular, a tensile force is applied to the steel plate when the steel plate and the inductor are relatively reciprocated to repeatedly perform the heat treatment. The present invention relates to a tensile force imparting type crystal grain refining process.

  With regard to the heat treatment of steel, ultra-fine-grained steel materials can be obtained by a treatment method in which rapid heat treatment is performed immediately above Ac3, followed by rapid cooling, and the strength and toughness both increase if crystal grains are refined. The hardness and toughness are both achieved and the fracture toughness is achieved by simultaneously forming hardness and toughness by repeating rapid heating and quenching that reciprocate between the austenitizing temperature range and martensitic transformation temperature range multiple times on the surface of the steel. It is also known that rapid heating can be realized by high-frequency induction heating and rapid cooling by water cooling.

  In addition, for a finite-length steel sheet (see, for example, Patent Document 1), a steel sheet heat treatment apparatus suitable for carrying out a grain refinement process that increases fracture toughness while maintaining high hardness has been developed. A support member that engages both ends of the steel sheet in the longitudinal direction and holds the steel sheet in a state in which the longitudinal direction is oriented in the vertical direction and in an allowable bending state, and a lifting mechanism that moves the steel sheet in the longitudinal direction via the support member And a heat treatment unit that combines an inductor for moving heating of the steel plate and a water discharge part for rapid cooling of the steel plate, and a horizontal plane adjustment mechanism for adjusting the position and in-plane orientation by moving the heat treatment unit in the horizontal plane And.

  Furthermore (for example, refer to Patent Document 2), the steel plate is moved to the steel plate while moving the steel plate in the longitudinal direction for crystal grain refining treatment by repeatedly applying heat treatment to the steel plate of finite length and applying rapid heating and subsequent quenching. In a steel plate heat treatment apparatus that sequentially applies induction heating and subsequent water discharge cooling, it is also known to have a holding mechanism that sandwiches both ends in the longitudinal direction of the steel plate over the entire width and pulls the steel plate in the longitudinal direction. . The steel plate holding mechanism acts on the movable frame that is linearly movable, another holding tool fixed to the movable frame, another non-fixed holding tool, and the non-fixed holding tool to apply a tensile force to the steel plate. A tensile force applying member. The tensile force applying member is embodied by a hydraulic cylinder or the like, and the tensile force is accurately controlled by feedback control.

JP 2006-348339 A JP 2009-167440 A

With such a tensile force application method, the steel sheet can be set in an inclined position close to the horizontal position, and the grain refinement process can be applied to the steel sheet by an inclined tilt close to the horizontal position and lateral movement. Therefore, in addition to reducing the cost of equipment and facilities, the burden of steel plate setting work can be reduced.
However, when a tensile force is applied in the longitudinal direction and the steel sheet is heat-treated, elongation deformation occurs in the longitudinal direction and shrinkage deformation occurs in the width direction and thickness direction. If repeated, the deformation accumulates and increases.

Therefore, in applications with strict requirements for finished dimensions, select the steel plate to be processed so that the size after processing is slightly larger than the required size, and perform grain refinement processing. You will only punch it. This processing can be performed without inconvenience by pressing or shearing in the longitudinal direction and the width direction.
However, regarding the plate thickness, adjustment in post-processing is not preferred. This is because it takes time and money to precisely cut a large surface, and above all, it causes surface roughness and weakening.

For this, it is conceivable to measure the plate thickness and adjust the processing contents according to the plate thickness change.However, in order to accurately measure the originally thin plate thickness, an expensive measuring instrument is required. It must be installed so as not to obstruct reciprocal movement, but it is not clear which part of the wide surface of the steel plate should be measured in the first place.
Therefore, it is a basic technical issue to be able to adjust the content of the tensile force imparting type crystal grain refinement process by using a physical quantity that can be measured more easily than the plate thickness and can narrow down the measurement content instead of the plate thickness. It becomes. In addition, by actually measuring such physical quantity and adjusting the content of the tensile force imparting type crystal grain refinement process according to the physical quantity, the measured quantity is finally obtained to obtain a steel sheet with a desired thickness. It is a further technical problem to modify the processing contents.

  The steel plate heat treatment method of the present invention (Solution 1) was devised in order to solve such a problem, and the steel plate having the required specification thickness is moved while being pulled in the longitudinal direction while being moved by induction heating. And the subsequent heat treatment that sequentially applies water discharge cooling together with the reciprocating movement, the expected thickness shrinkage that occurs in the steel sheet when the crystal grains of the steel sheet are refined is based on the shape and physical properties of the steel sheet. After calculating or calculating an estimated value of the plate length elongation generated in the longitudinal direction of the steel sheet based on the shape and physical properties of the steel sheet, the estimated value of the plate length elongation is calculated based on the shape and physical properties of the steel sheet. Convert to the expected thickness reduction value, select a steel plate that is thicker than the expected thickness reduction value of the required specification, and the difference between the selected steel plate thickness value and the required specification thickness value. Is the thickness reduction target value. The thickness shrinkage target value is converted into the plate length elongation target value of the steel plate based on the shape and physical properties of the steel plate, and the grain refinement is performed based on the comparison between the plate length elongation target value and the plate length elongation expected value. The tensile force at the time of processing execution is adjusted.

The steel plate heat treatment method of the present invention is (Solution means 2), which is the steel plate heat treatment method of Solution 1 described above, by increasing the number of repetitions of the heat treatment when adjusting the tensile force during execution of the grain refinement treatment. , Which suppresses an increase in tensile force.
These are defined from the stage of finalizing the conditions for selecting the steel plates (solution means 1-2).

Furthermore, the steel plate heat treatment method of the present invention (Solution means 3) repeats the heat treatment in which induction heating and subsequent water cooling are sequentially applied to the steel plate while reciprocating while the finite length steel plate is moved while being pulled in the longitudinal direction. In the steel plate heat treatment method for refining crystal grains of the steel plate, a steel plate that is thicker than a required thickness value is selected, and the target plate length elongation when the heat treatment is applied to the selected steel plate When the heat treatment is repeated using the plate length elongation target value calculated or determined based on the shape and physical properties, the plate length elongation target value and the steel plate It is characterized in that the tensile force in the subsequent heat treatment is adjusted based on the comparison with the measured value of the plate length elongation in the longitudinal direction.
This prescribes a manufacturing process that is repeated after the steel plate selection conditions are established.

Further, the steel plate heat treatment apparatus of the present invention (Solution means 4) is a longitudinal direction of the steel plate for grain refinement treatment that is performed by repeatedly performing heat treatment applying rapid heating and subsequent quenching to a finite length steel plate. In the steel plate heat treatment apparatus that sequentially applies induction heating and subsequent water discharge cooling to the steel plate while being moved to, the fixed clamp that is fixed to the movable frame that is linearly movable and the non-fixed clamp that is not fixed The holding mechanism for holding the both ends in the longitudinal direction of the steel plate over the entire width and pulling the steel plate in the longitudinal direction is provided with a displacement meter for measuring the displacement of the non-fixed holding tool with respect to the movable frame. And
This contributes to the implementation of the steel plate heat treatment method of Solution 3 described above.

Further, the steel plate heat treatment apparatus of the present invention (Solution means 5) is the steel plate heat treatment apparatus of the above solution means 4, and is provided with a control unit for controlling execution and repetition of the heat treatment, and the control unit is provided on the steel plate. Means for calculating the plate length elongation target value when the heat treatment is performed based on the shape and physical properties of the steel sheet, and when repeating the heat treatment, between the preceding heat treatment and the subsequent heat treatment, And a means for adjusting the tensile force in the subsequent heat treatment based on a comparison between the target plate length elongation value and the value measured by the displacement meter.
This enables automatic execution of the steel plate heat treatment method of the solution 3 described above.

  Further, the steel plate heat treatment apparatus of the present invention (solution 6) is the steel plate heat treatment apparatus of the solution 5, wherein the control unit divides or divides the plate length elongation target value by the time of the heat treatment. Means for calculating an equal elongation target value, means for calculating at any time an elongation measurement value which is a variable per unit time from the measurement value obtained by the displacement meter during the heat treatment, the elongation target value and the And means for finely adjusting the tensile force during the heat treatment based on the comparison with the measured elongation rate.

  Further, the steel plate heat treatment apparatus of the present invention (Solution means 7) is a method of refining the steel plate in the longitudinal direction for grain refinement treatment by repeatedly performing heat treatment applying rapid heating and subsequent quenching to a finite length steel plate. In the steel plate heat treatment apparatus that sequentially applies induction heating and subsequent water discharge cooling to the steel plate while being moved to, the fixed clamp that is fixed to the movable frame that is linearly movable and the non-fixed clamp that is not fixed A holding mechanism that holds both ends in the longitudinal direction of the steel plate over the entire width and pulls the steel plate in the longitudinal direction, and a displacement meter that is attached to the holding mechanism and measures the displacement of the non-fixed holding tool with respect to the movable frame And a control unit that controls execution and repetition of the heat treatment, and the control unit determines a target plate length elongation value when the heat treatment is performed on the steel plate based on the shape and physical properties of the steel plate. The Means for calculating the elongation target value obtained by dividing the plate length elongation target value by or equal to the time of the heat treatment, and the unit from the value measured by the displacement meter during the heat treatment. Means for calculating an elongation measurement value, which is a variable per hour, as needed, and means for finely adjusting a tensile force during the heat treatment based on a comparison between the elongation target value and the elongation measurement value. It is characterized by.

  In such a steel plate heat treatment method of the present invention (solution means 1 and 2), in addition to selecting a steel plate in consideration of the reduction in plate thickness, the final plate thickness of the selected steel plate is matched with the required specifications. In the adjustment of the processing content, longitudinal elongation is used instead of or in addition to the plate thickness. This elongation is equivalent to the ratio of the plate thickness to the total length of the steel plate, and the ratio of the thickness reduction to the total length of the steel plate is suitable for substituting the plate thickness reduction by simple conversion, etc. Easy to measure. In addition, the total length of the steel plate only needs to be measured by measuring the distance between both ends of the steel plate, so the measurement area can be easily narrowed down compared to the plate thickness distributed over a wide surface, and the single measurement value can be used. Is common.

Further, the use of tensile force is not limited to the passive use of preventing the hanging of horizontally placed and inclined steel plates, but has been extended to the active use of adjusting the content of the tensile force imparting crystal grain refinement process. In addition, the adjustment is not performed based on the measurement value of the plate thickness itself of the target directly, but based on the measurement value of the elongation in the longitudinal direction of the steel plate substituting the plate thickness. Therefore, it is possible to easily adjust the thickness reduction without adding a new adjustment mechanism or an expensive measuring instrument.
Therefore, according to the present invention, the content of the tensile force imparting type crystal grain refining treatment can be obtained by using the longitudinal elongation, which is a physical quantity that can be measured more easily than the plate thickness and can narrow down the measurement content, in place of the plate thickness reduction. By making adjustments, even when the required accuracy for finished dimensions is severe, it is possible to meet the requirements with relatively inexpensive equipment and equipment and to perform steel plate setting work easily.

Moreover, in the steel plate heat treatment method and the steel plate heat treatment apparatus of the present invention (solution means 3 to 5), the use of the tensile force is not limited to the negative use of preventing the sag of the horizontally or inclinedly placed steel plate, and the tensile force is applied. It has been extended to the active use of adjusting the content of the formula grain refinement process. In addition, the adjustment is not performed based on the measurement value of the plate thickness itself of the target directly, but based on the measurement value of the elongation in the longitudinal direction of the steel plate substituting the plate thickness. Therefore, it is possible to easily adjust the thickness reduction without adding a new adjustment mechanism or an expensive measuring instrument. In addition, using the fact that the grain refinement process is performed repeatedly by heat treatment, adjustment of the tensile force based on the measured plate length elongation is performed between heat treatments, so the work of measurement and adjustment is light and manual. Is also possible.
Therefore, according to the present invention, the longitudinal elongation, which is a physical quantity that can be measured more easily than the plate thickness and can narrow down the measurement content, is measured instead of the plate thickness shrinkage, and the tensile force imparting type crystal grains are measured according to the physical quantity. Since the content of the refinement process is adjusted, a steel sheet having a desired thickness is finally obtained.

  Furthermore, in the steel plate heat treatment apparatus of the present invention (solution means 6 to 7), only the elongation in the longitudinal direction of the steel plate, i.e., the elongation of the entire length, is measured. Since the local elongation rate in the longitudinal direction of the steel sheet is adjusted, as a result, the plate thickness is finely adjusted for each longitudinal part of the steel sheet.

About Example 1 of this invention, the structure of a steel plate heat processing apparatus is shown, (a) is a top view of a steel plate holding mechanism, (b) is a front view of the machine part which removed the water receiver, (c) is a control part. It is a block diagram. The control procedure is specifically shown, in which (a) is a flowchart of the plate thickness selection program, and (b) is a flowchart of a part related to the sequence control program, particularly relating to the tensile force adjustment function. It is a flowchart which shows the one part processing content of the tensile force adjustment function in the sequence control program of the control part of the steel plate heat processing apparatus about Example 2 of this invention.

About the steel plate heat processing method and steel plate heat processing apparatus of this invention, the specific form for implementing this is demonstrated by the following Examples 1-2.
The embodiment 1 shown in FIGS. 1 and 2 embodies the above-described solving means 1 to 5 (claims 1 to 5 at the beginning of the application), and the embodiment 2 shown in FIG. Means 6 to 7 (claims 6 to 7 as originally filed) are embodied.
In the illustration, for the sake of simplicity, fasteners such as bolts, coupling tools such as hinges, drive sources such as electric motors, transmission members such as ball screws, electric circuits such as motor drivers, etc. are shown. In the figure, the elements necessary for explaining the invention and the related ones are mainly illustrated.

About the Example 1 of the steel plate heat processing apparatus of this invention, the specific structure is demonstrated referring drawings.
1A is a plan view of the steel plate holding mechanisms 11 to 15, FIG. 1B is a front view of the mechanical unit 10 with a water receiver (not shown) removed, and FIG. 1C is a block diagram of the control unit 20. 2A is a flowchart of the plate thickness selection program 22 of the control unit 20, and FIG. 2B is a flowchart of a portion related to the tensile force adjustment function particularly regarding the sequence control program 24 of the control unit 20.

This steel plate heat treatment apparatus 10 + 20 is broadly divided into a mechanical unit 10, a control unit 20, a high-frequency power supply device and a water cooling device for ancillary equipment (not shown), and follows the tension applying method described above (see Patent Document 2). ) Since the grain refinement process can be performed by setting the steel plate 8 sideways or with a slight inclination, the steel plate 8 is relatively inexpensive and facilitates the steel plate setting work.
Moreover, the mechanical unit 10 and the control unit 20 are improved so that the finished plate thickness meets the required specification even if the required specification related to the plate thickness D is severe even if the conventional technology is followed. Specifically, the tensile forces P and Pa are adjusted by measuring the plate length elongation ΔL.

  When the mechanical unit 10 (see FIG. 1B) repeatedly performs a heat treatment that applies rapid heating and subsequent rapid cooling as a grain refinement process on a thin steel plate 8, the longitudinal direction of the steel plate 8 is increased. While applying rapid heating to the steel plate 8 by induction heating and moving to the steel plate 8, rapid cooling is applied to the steel plate 8 by subsequent water discharge cooling. For this purpose, the steel plate holding mechanisms 11 to 15, the water discharge part 16, the inductor 17, the radiation thermometer 18, the inclined base 19, the leg part, and a water receiver (not shown) are provided.

  The steel plate holding mechanisms 11 to 15 (see FIG. 1 (a)) can be moved linearly to the tilting table 19 in order to hold the both ends of the steel plate 8 in the longitudinal direction and pull the steel plate 8 in the longitudinal direction. A movable frame 13 to be mounted, a fixed holding tool 11 fixed to the movable frame 13, another non-fixed holding tool 12 which is disposed opposite to the movable frame 13 and is not fixed to the movable frame 13, and the non-fixed holding tool A tensile force applying member 14 that applies a tensile force to the steel plate 8 between the pair of sandwiching tools 11, 12 by acting on the tool 12 and trying to separate the pair of sandwiching tools 11, 12, and the scale portion is a non-fixed sandwiching tool A reading unit is mounted on the movable frame 13 and is attached to the twelve interlocking members, and includes a displacement meter 15 that measures the displacement of the non-fixed holding tool 12 with respect to the movable frame 13.

  The holding tools 11 and 12 are sufficient if they extend over the entire width of the steel plate 8, but the upper part is swinging on the lower side and the cross-sectional shape is U-shaped when clamped and L-shaped when released. easy. The tensile force imparting member 14 is embodied by a hydraulic cylinder or the like, and a proportional electromagnetic relief valve or the like is incorporated into the hydraulic pressure supply unit in order to generate a tensile force indicated by a tensile force target value Pa, which will be described later. A pressure gauge and an amplifier are also combined for feedback control, and a tensile force controlled with high precision is stably applied over the entire length of the steel plate 8. The displacement meter 15 desirably has a resolution smaller than [mu] m. However, for example, a highly accurate linear scale using visible light or laser light is commercially available. Since the measured value by the displacement meter 15 attached to the steel plate holding mechanisms 11 to 15 becomes the measured value of the plate length elongation ΔL of the steel plate 8, it is taken into the control unit 20 as the measured plate length elongation value ΔLm. (See FIG. 1B).

The tilting table 19 (see FIG. 1B) is mainly composed of a linear / parallel-line frame, and a movable frame 13 is mounted on the tilting table 19 so as to linearly move / reciprocate at a constant speed or high speed in the longitudinal direction. There is a drive source such as a servo motor. The inclination angle θ may be fixed at 10 °, for example, but in this example, it can be variably set within a range of 5 ° to 20 °, for example.
In order to prevent the cooling water from flowing down or dissipating, the water receiver is externally mounted on the inclined base 19 so as to surround from the bottom to the side of the inclined base 19, and the end of the water receiver is used to collect the cooling water. A drain outlet is formed in the section, and a drain hose is connected there.

The inductor 17 (see FIG. 1B) is made of a good electrical conductor such as a water-coolable copper tube, is wound in a coil shape, and is mounted at a substantially central position of the inclined base 19. Since the position surrounds the linear moving path of the steel plate 8, the inductor 17 induction-heats the facing portion of the steel plate 8 when a high-frequency current is applied from the high-frequency power supply device. Further, since the inductor 17 is for moving heating, with respect to the facing state with respect to the steel plate 8, the steel plate 8 faces the steel plate 8 over the entire area in the width direction of the steel plate 8, and the steel plate 8 is partly in the longitudinal direction of the steel plate 8. It comes to confront with.
The radiation thermometer 18 is attached to an inclined table 19 and measures the temperature of a portion of the steel plate 8 that is induction-heated.

  The water discharge part 16 (see FIG. 1B) is mounted on the inclined base 19 and is located on the immediate side of the inductor 17 in order to perform rapid cooling after rapid heating of the moving steel plate 8, The steel plate 8 held by the steel plate holding mechanisms 11 to 15 faces the entire area in the width direction and partly in the longitudinal direction. Since the heat treatment is performed while moving the steel plate 8 obliquely along the inclination of the inclined table 19, the water discharger 16 is located obliquely below the inductor 17 (lower left in the figure), and the movement path of the steel plate 8 It is attached to the tilting table 19 so as to surround. A large number of injection holes are formed in the water discharge part 16 in a row in the width direction of the steel plate 8, and at the time of water discharge, cooling water adjusted to an appropriate amount from the water cooling device via the water supply circuit is supplied from each injection port to the steel plate 8. It is designed to be jetted towards.

  The control unit 20 (see FIG. 1C) includes, for example, a programmable microprocessor system or sequencer, and the data memory includes a plate thickness list data area 21, a processing condition data area 23, a tensile force data area 27, and other appropriate values. A work area is allocated in advance, and a plate thickness selection program 22, an order control program 24, a temperature control program 25, a movement control program 26, and a tensile force control program 28 are preinstalled in the program memory. The operation unit of the control unit 20 is provided with, for example, a touch panel as a member used for input and display, and is further connected to a detection member and a control target member (14 to 19) of the machine unit 10 through an appropriate interface. Necessary signals are input and output.

In the plate thickness list data area 21, data of the steel plate 8 that can be used for crystal grain refinement processing is stored in advance based on JIS standards, manufacturer standards, and the like. Are included, and when the selectable plate thickness is limited by the plate length or the plate width, data reflecting the limiting conditions is also included.
In the processing condition data area 23, a plate thickness D, a plate width W, and a plate length L that define the shape of the steel plate 8 based on the required specifications, a high temperature longitudinal elastic modulus E that is one of the physical properties of the steel plate 8, and Defines the selected plate thickness Ds and plate length elongation target value ΔLa for the selected steel plate 8, the high frequency power that defines the specific content of the heat treatment, the feed rate V, the heating temperature, and the number of times of heat treatment suitable for the grain refinement treatment. The number of heat treatments n and the tensile force P that defines the tensile force at the start of the treatment are included.
The tensile force data area 27 stores and holds the tensile force target value Pa during the heat treatment.

The plate thickness selection program 22 refers to the plate thickness list data region 21 on the assumption that data values other than the selected plate thickness Ds and the plate length elongation target value ΔLa are set in the processing condition data region 23. While the steel plate 8 to be subjected to the grain refinement process is selected, the selected plate thickness Ds and the plate length elongation target value ΔLa are set and the tensile force P is corrected or the tensile force P and the heat treatment number n are corrected. The details will be described later in the explanation of the operation.
The sequence control program 24 executes the crystal grain refining process by controlling each part (14 to 19) of the machine part 10 based on the data set in the processing condition data area 23. The tensile force of the steel plate 8 is adjusted, details of which will be described later in the explanation of the operation.

The temperature control program 25 controls the feedback of the temperature so that the heat treatment is performed at a constant temperature under the control of the sequence control program 24. Specifically, the heating of the steel plate 8 detected by the radiation thermometer 18 during the heat treatment. The energization amount of the inductor 17 output from the high frequency power supply is controlled so that the temperature of the section becomes the heating temperature of the processing condition data area 23. The water cooling device is controlled to discharge water from the water discharge unit 16 or stop water discharge.
The movement control program 26 controls the feed rate so that the heat treatment is performed at a constant speed under the control of the sequence control program 24. Specifically, the movement control program 26 holds the steel plate that moves on the tilt table 19 during the heat treatment. The operation of the drive source of the tilting table 19 is controlled so that the mechanisms 11 to 15 and the feed rate of the steel plate 8 become the feed rate V in the processing condition data area 23.

The tensile force control program 28 is a feedback control of the tensile force so that the heat treatment is performed with a constant force under the control of the sequence control program 24. Specifically, the tensile force application member 14 is discharged during the heat treatment. For example, the pressure of the hydraulic pressure applied to the tensile force applying member 14 is detected by a pressure gauge so that the tensile force becomes the tensile force target value Pa in the tensile force data area 27, and the hydraulic pressure is correspondingly detected by a proportional electromagnetic relief valve or the like. The pressure control valve adjusts it.
The tensile force target value Pa in the tensile force data area 27 is set or changed by the sequence control program 24, and details thereof will be described later in the explanation of the operation.

  The steel plate heat treatment method using the steel plate heat treatment apparatus 10 + 20 of Example 1 and the operation of the steel plate heat treatment apparatus 10 + 20 will be described.

  The material of the steel plate 8 to be processed is one in which crystal grains are refined by repeated rapid heating and rapid cooling, and examples thereof include JIS G3128 (SHY) and JIS G4103 (SNCM) (see Patent Document 1). . The size of the steel plate 10 to be a thick plate is typically about 16 mm thick x 1200 mm wide x about 6000 mm long, but other sizes may be used. As a guide, the thickness is 10 to 25 mm and the width is 900 to 900 mm. The length is 1200 mm and the length is 2000 to 6000 mm. The size of the thin steel plate 20 is typically about 5 mm thick x 700 mm wide x about 1200 mm long, but other sizes may be used. As a guide, the thickness is 3 to 12 mm and the width is 300 to 800 mm. The length is 500 to 2000 mm (see Patent Document 2).

Prior to the execution of the process, the steel sheet 8 having a thickness reduction ΔD that is thicker than the required specification thickness D must be selected in consideration of the reduction of the thickness in the crystal grain refinement process of the tensile force application method. Apart from the case where the same processing has already been executed and the selection data at that time can be reused, the plate thickness selection work is performed.
The plate thickness selection operation may be performed manually using a writing instrument, a scientific calculator, or the like, but here, the plate thickness selection program 22 installed in the steel plate heat treatment apparatus 10 + 20 is automatically selected.

For this purpose, first, the touch panel is operated to set a previously determined data value in the processing condition data area 23.
Specifically, the plate thickness D, the plate width W, the plate length L, and the high temperature longitudinal elastic modulus E are set in the corresponding locations in the processing condition data area 23 based on the required specifications, and based on past experience and new experiments. Thus, the high frequency power, the feed rate V, the heating temperature, the number of heat treatments n, and the tensile force P are also set in the corresponding locations of the processing condition data area 23. The plate thickness D must be set to the value of the required specification as it is, but the plate width W and the plate length L are preferably slightly larger than the value of the required specification.

  When the plate thickness selection program 22 is activated, automatic processing is started by the plate thickness selection program 22 (see FIG. 2A), and a plate length elongation expected value ΔLe is first calculated (step S11). The expected plate length elongation value ΔLe is obtained by repeating the heat treatment that sequentially applies induction heating and subsequent water cooling to the steel plate 8 while moving the steel plate 8 having the required thickness D while pulling in the longitudinal direction. This is a calculated value for predicting the plate length elongation ΔL that will occur in the longitudinal direction of the steel plate 8 when the crystal grains of the steel plate 8 are refined, and the plate thickness D, plate width W, and plate that define the shape of the steel plate 8 From the length L, the high-temperature longitudinal elastic modulus E, which is one of the physical properties of the steel plate 8 and also reflects the heat treatment conditions, and the number of heat treatments n and the tensile force P, for example, the formula [ΔLe = (P × L × n) / ( D × W × E)].

Then, the expected length elongation value ΔLe is converted to the expected thickness reduction value ΔDe by the formula [ΔDe = ΔLe / (L × m)] including the Poisson's ratio m (step S12) and set in the thickness list data area 21. Among the selectable plate thicknesses D1, D2,..., A plate thickness that is equal to or greater than the total value of the plate thickness D and the estimated thickness shrinkage ΔDe and closest to the total value is selected (step S13). The selected plate thickness Ds is set at the corresponding location in the processing condition data area 23 (step S14).
In addition, information on the selected plate thickness Ds and the selected steel plate with the selected plate thickness is displayed on the touch panel, and the selected plate thickness Ds which is the plate thickness value of the selected steel plate and the plate thickness D which is the plate thickness value of the required specification. The difference is calculated to be a plate thickness shrinkage target value ΔDa, and this plate thickness shrinkage target value ΔDa is converted into a plate length elongation target value ΔLa of the steel plate 8 based on the shape and physical properties of the steel plate 8 to obtain a plate length elongation target value. Similarly to the selected plate thickness Ds, ΔLa is also set at a corresponding location in the processing condition data area 23 (step S14).

Conversion from the plate thickness shrinkage target value ΔDa to the plate length elongation target value ΔLa is performed by, for example, an equation [ΔLa = ΔDa × L × m × K] including a coefficient K. The coefficient K may be a value “1” when the steel plate 8 has no anisotropy or when the anisotropy of the steel plate 8 can be ignored. , ΔDa is measured, and a value calculated backward based on the above formula is used.
Further (step S15), the tensile force P at the time of executing the grain refinement process is adjusted based on the comparison between the plate length elongation target value ΔLa and the above-described plate length elongation expected value ΔLe. Specifically, the equation [(ΔLa / ΔLe) × P] is calculated, and the tensile force P in the processing condition data area 23 is reset with the calculated value. If the operation mode permits the automatic increase of the heat treatment number n and the old P <{new P × n / (n + 1)}, the tensile force P is reset and the heat treatment number n is incremented by one.

  Thus, after the plate thickness is selected, the inductor 17 and the water discharger 16 that match the size of the selected steel plate 8 are attached to the inclined base 19 to adjust the position and posture, and the steel plate 8 is set in the machine unit 10. . This setting operation is performed by a handling device equipped with an available crane, a steel plate adsorption machine, etc. with a pair of holding tools 11 and 12 mounted at both ends of the movable frame 13 on the tilting table 19 opened. While holding the target steel plate 8, the steel plate 8 is inserted into the inductor 17 and the water discharge portion 16, and both ends of the steel plate 8 are held between the holding tools 11 and 12, but the inclination angle θ is not so large. The setting work of the steel plate 8 including the loose insertion can be easily performed even in the case of tilting tilting, almost the same as in the horizontal movement.

  When the setting of the steel plate 8 to the machine unit 10 is completed, the set value of the processing condition data area 23 of the control unit 20 is confirmed. If the plate thickness is selected normally, all processing conditions should be set with appropriate data values, but the tensile force P and the number of heat treatments n have been changed even if normal. There is also. If it is assumed that the crystal grain refining process will be performed later under the same processing conditions, the processing condition data area 23 is saved in an external storage device or the like by a save program (not shown) for future reuse. . If this time is reuse, the corresponding processing condition is searched from the stored data and restored to the processing condition data area 23.

  After confirming the processing conditions, the sequence control program 24 is started, and the rest is left to automatic control of the control unit 20. Then (see FIG. 2B), by executing the sequence control program 24, the tensile force P in the processing condition data area 23 is transferred to the tensile force data area 27 in preparation for adjustment change (step S21). The target tensile force Pa referred to by the program 28 is obtained. Further, it is checked whether or not the plate length elongation target value ΔLa is set in the processing condition data area 23 (step S22). If it is set, it is left unchanged but is not set. In this case, the plate length elongation target value ΔLa is calculated, and data is set in the corresponding portion of the processing condition data area 23 (step S23).

The calculation of the plate length elongation target value ΔLa is omitted in the detailed description which will be repeated, but may be the same calculation as the plate thickness selection program 22 described above.
When the plate length elongation target value ΔLa is determined, the plate length elongation target value (ΔL / n) a, which is the target value of the plate length elongation ΔL per heat treatment, is obtained from the plate length elongation target value ΔLa and the number of heat treatments n. It is calculated by the equation [ΔLa / n] (step S24).
Since the control unit 20 is now ready for heat treatment, the order control program 24 instructs the temperature control program 25, the movement control program 26, and the tensile force control program 28 to execute the heat treatment once. Heat treatment is executed only once at a constant speed and a constant force (step S25).

Specifically, the inductor 17 is initially energized with the high-frequency power value in the processing condition data area 23 by the high-frequency power source under the control of the temperature control program 25, and after the settling time has elapsed, the radiation thermometer 18 The energization amount is adjusted so that the measured temperature becomes the heating temperature of the processing condition data area 23. Further, by the drive source such as a servo motor under the control of the movement control program 26, the steel plate holding mechanisms 11 to 15 and the steel plate 8 are moved at a constant speed at the feed speed V in the processing condition data area 23 on the tilt table 19. Further, the tensile force generated by the tensile force applying member 14 and acting on the steel plate 8 by the pressure control of the hydraulic circuit under the control of the tensile force control program 28 becomes the tensile force target value Pa in the tensile force data area 27. So that it is automatically adjusted.
When the plate is moved and heated from one end to the other end of the steel plate 8, high-frequency energization is stopped and the steel plate holding mechanisms 11 to 15 and the steel plate 8 are fed back to return to their original positions and one heat treatment is completed.

(Step S26) When the number of heat treatments performed reaches the number n of heat treatments in the processing condition data area 23, the fact is displayed on the touch panel and the sequence control program 24 finishes execution. If n has not yet been reached, the plate length elongation ΔL generated in the steel plate 8 in the immediately preceding heat treatment is measured by the displacement meter 15 and is taken in as the plate length elongation measured value ΔLm (step S27), and the above-described plate length elongation target value is obtained. Based on the comparison between (ΔL / n) a and the measured plate length elongation value ΔLm, the tensile force in the subsequent heat treatment is adjusted.
Specifically (step S28), for example, the equation [{(ΔL / n) a / ΔLm} × Pa] is calculated, and the calculated value is written in the tensile force data area 27 as a new tensile force target value Pa. .

After the adjustment of the tensile force, the heat treatment is performed once again at a constant temperature, a constant speed, and a constant force (step S25). Then, until the number of executed times reaches the number of heat treatments n (step S26), the tensile force adjustment in the subsequent heat treatment (steps S27 to S28) and the single heat treatment execution at a constant temperature, constant speed, and constant force (steps) S25) is repeated (step S26).
Thus, when the heat treatment is repeated n times, the grain refinement process of the steel plate 8 is completed, and that fact is displayed on the touch panel and the automatic control of the control unit 20 is stopped. If it is removed from the section 10, all work including manual cleanup is completed.

  In addition, the finished steel plate 8 has a finished plate thickness that is adjusted by the tensile force in the subsequent heat treatment according to the result of the preceding heat treatment so that the plate thickness shrinkage ΔD becomes the plate thickness shrinkage target value ΔDa. It will conform to the required specification thickness D with high accuracy. Moreover, the adjustment of the tensile force is not performed by measuring the plate thickness of the steel plate 8 itself, but based on the plate length elongation measurement value ΔLm obtained by measuring the elongation in the longitudinal direction of the steel plate 8 substituting the plate thickness with the displacement meter 15. The displacement meter 15 is attached to the same movable frame 13 and non-fixed holding tool 12 as the attachment destination of the tensile force imparting member 14, thereby preventing any heat treatment including movement of the steel plate holding mechanisms 11 to 15. Since it is attached to the steel plate holding mechanisms 11 to 15, adjustment of the plate thickness reduction is easily and accurately performed.

  About Example 2 of the steel plate heat processing apparatus of this invention, the specific structure is demonstrated referring drawings. FIG. 3 is a flowchart showing part of the processing content of the tensile force adjustment function in the sequence control program of the control unit of the steel plate heat treatment apparatus.

This steel plate heat treatment apparatus is different from that of the first embodiment described above in that the tensile force is adjusted not only between the heat treatments but also during each heat treatment.
That is, while the heat treatment of Example 1 was performed at a constant temperature, constant speed, and constant force once (Step S25), the heat treatment of Example 2 maintained constant temperature and constant speed. The tensile force generated by the tensile force applying member 14 and acting on the steel plate 8 is adjusted as needed. Specifically (see FIG. 3), the sequence control program 24 is partially remodeled so that the tensile force target value Pa in the tensile force data area 27 is updated as needed (steps S31 to S36).

More specifically, when the heat treatment is performed once, the sequence control program 24 first calculates the elongation target value (dL / dt) a by the equation [(ΔL / n) a × V / L] (step S31). ). This calculated value is equal to the target plate length elongation (ΔL / n) a per heat treatment divided by the time per heat treatment (L / V). Even if it is calculated by the equation [ΔLa × V / L / n], it is equal.
Then, since the sequence control program 24 issues an instruction to execute the heat treatment once to the temperature control program 25, the movement control program 26, and the tensile force control program 28, the heat treatment is started (step S32). 24, the tensile force target value Pa in the tensile force data area 27 is updated as needed. Therefore, the tensile force of the steel plate 8 can also be changed as needed by the control of the tensile force control program 28 that follows it. The constant temperature control by the temperature control program 25 and the constant speed feed control by the movement control program 26 are performed based on the corresponding set values in the processing condition data area 23 and are maintained because the processing condition data area 23 is not updated.

  Update of the tensile force target value Pa in the tensile force data area 27 by the sequence control program 24 is performed by taking the plate length elongation ΔL measured by the displacement meter 15 from the displacement meter 15 at an appropriate timing (step S33). Divide the difference from the previous value by the elapsed time of both acquisitions to calculate the measured elongation rate (dL / dt) m, which is a variable per unit time of the plate length elongation ΔL (step S34). A series of processes of adjusting the tensile force target value Pa in the tensile force data area 27 based on the comparison between the rate target value (dL / dt) a and the measured elongation rate (dL / dt) m (step S35) ( Steps S33 to S35) are performed by repeating the heat treatment at a constant cycle or an indefinite cycle until one heat treatment is completed (step S36).

In this case, for example, the tensile force target value Pa in the tensile force data area 27 is calculated by the calculated value of the same expression [{(dL / dt) a / (dL / dt) m} × Pa] that is performed between heat treatments. Although adjustment may be performed, since this adjustment is repeated in a short time, if there is a concern that undesired oscillation or divergence may occur, an appropriate attenuation coefficient α smaller than “1” is introduced, for example, the equation [ The tensile force target value Pa in the tensile force data area 27 may be finely adjusted with a calculated value of Pa + α × {(dL / dt) a / (dL / dt) m} × Pa]. The attenuation coefficient α may be a constant or a variable that takes into account the time interval of measurement of the plate length elongation ΔL.
Since such fine adjustment of the tensile force is performed during the heat treatment, that is, while the steel plate 8 is moving, the thickness of the steel plate 8 is finely adjusted for each part in the longitudinal direction of the steel plate 8, so that the processed steel plate No. 8 is good up to the uniformity of the plate thickness distribution.

[Others]
In the above embodiment, the excess or deficiency of the elongation in the preceding heat treatment was only used to optimize the elongation in the subsequent heat treatment, but the excess or deficiency of the elongation in the preceding heat treatment was compensated in the subsequent heat treatment. For example, the excess or deficiency of the preceding may be increased and reflected in the subsequent.
In the above embodiment, the inclination of the tilting table 19 is only left-down, but it is also possible to provide a leg-lowering posture by providing stretchable legs at both ends of the tilting table 19 and alternately expanding and contracting, In this case, heat treatment may be performed both in reciprocal movement (see Patent Document 2).

  The steel plate heat treatment method and the steel plate heat treatment apparatus according to the present invention are not limited to application to thin finite-length steel plates, and can be thick plates as long as they are held at both ends and are provided with an appropriate tensile force. It can also be applied to finite-length steel plates that are close to or belong to a thick plate.

8 ... Steel plate (thin plate),
10: Machine part (steel plate heat treatment device),
11 ... clamping tool (fixed), 12 ... clamping tool (non-fixed),
13 ... movable frame, 14 ... tensile force applying member, 15 ... displacement meter,
16 ... Water discharge part, 17 ... Inductor, 18 ... Radiation thermometer, 19 ... Inclination stand,
20 ... Control unit (steel plate heat treatment device),
21 ... Plate thickness list data area, 22 ... Plate thickness selection program,
23 ... Processing condition data area, 24 ... Sequence control program,
25 ... temperature control program, 26 ... movement control program,
27 ... Tensile force data area, 28 ... Tensile force control program

Claims (7)

When the crystal grain of the steel sheet is refined by repeating the reciprocating heat treatment that sequentially applies induction heating and subsequent water cooling to the steel sheet while moving the steel sheet having the required specification thickness in the longitudinal direction. In calculating the expected thickness shrinkage occurring in the steel sheet based on the shape and physical properties of the steel sheet, the expected length elongation occurring in the longitudinal direction of the steel sheet is calculated based on the shape and physical properties of the steel sheet. From the plate length elongation expected value based on the shape and physical properties of the steel plate is converted into a plate thickness shrinkage expected value of the steel plate, a steel plate that is thicker than the plate thickness shrinkage expected value than the required specification plate thickness value The difference between the plate thickness value of the selected steel plate and the plate thickness value of the required specification is set as a plate thickness reduction target value, and the plate thickness reduction target value is determined based on the shape and physical properties of the steel plate. Converted to the target for long growth, this Steel heat treatment method of adjusting the tension during grain refinement process performed based on the comparison between the plate length elongation forecast length elongation target value.   The steel plate heat treatment method according to claim 1, wherein an increase in the tensile force is suppressed by increasing the number of repetitions of the heat treatment when adjusting the tensile force during the execution of the crystal grain refining treatment.   In a steel plate heat treatment method for refining crystal grains of the steel sheet by repeating a heat treatment that sequentially applies induction heating and subsequent water cooling to the steel sheet while moving the finite length steel sheet while pulling in the longitudinal direction. , Select a steel plate that is thicker than the required thickness value, and calculate or determine the plate length elongation target value when the selected steel plate is subjected to the heat treatment based on the shape and physical properties of the steel plate. When the heat treatment is repeated using the elongation target value, the subsequent heat treatment is followed based on a comparison between the plate length elongation target value and the measured longitudinal plate length of the steel sheet between the preceding heat treatment and the subsequent heat treatment. A steel plate heat treatment method characterized by adjusting a tensile force in the heat treatment.   The steel sheet is moved in the longitudinal direction for the grain refinement process by repeatedly applying a heat treatment to the steel sheet of finite length and the subsequent quenching, while the steel sheet is moved in the longitudinal direction, followed by induction heating and subsequent water cooling. In the steel plate heat treatment apparatus that sequentially applies, the both ends in the longitudinal direction of the steel plate are clamped over the entire width between the fixed holding tool fixed to the linearly movable movable frame and the non-fixed non-fixed holding tool. A steel plate heat treatment apparatus, wherein a displacement meter for measuring a displacement of the non-fixed holding tool with respect to the movable frame is attached to a holding mechanism for pulling the steel plate in its longitudinal direction.   A control unit for controlling execution and repetition of the heat treatment is provided, and the control unit calculates a plate length elongation target value when the steel plate is subjected to the heat treatment based on the shape and physical properties of the steel plate. When the heat treatment is repeated, the tensile force in the subsequent heat treatment is determined based on the comparison between the plate length elongation target value and the value measured by the displacement meter between the previous heat treatment and the subsequent heat treatment. The steel plate heat treatment apparatus according to claim 4, further comprising means for adjusting.   The control unit calculates the elongation target value equal to or equal to the plate length elongation target value divided by the time of the heat treatment, and the unit from the measurement value of the displacement meter during the heat treatment. Means for calculating an elongation measurement value, which is a variable per hour, as needed, and means for finely adjusting a tensile force during the heat treatment based on a comparison between the elongation target value and the elongation measurement value. The steel plate heat treatment apparatus according to claim 5, wherein   The steel sheet is moved in the longitudinal direction for the grain refinement process by repeatedly applying a heat treatment to the steel sheet of finite length and the subsequent quenching, while the steel sheet is moved in the longitudinal direction, followed by induction heating and subsequent water cooling. In the steel plate heat treatment apparatus that sequentially applies, the both ends in the longitudinal direction of the steel plate are clamped over the entire width between the fixed holding tool fixed to the linearly movable movable frame and the non-fixed non-fixed holding tool. A holding mechanism for pulling the steel plate in the longitudinal direction; a displacement meter attached to the holding mechanism for measuring the displacement of the non-fixed clamping tool with respect to the movable frame; and a control unit for controlling execution and repetition of the heat treatment. A means for calculating a plate length elongation target value when the steel plate is subjected to the heat treatment based on a shape and physical properties of the steel plate; and Means for calculating an elongation target value divided by or equal to time, and means for calculating at any time an elongation measurement value which is a variable per unit time from a measurement value obtained by the displacement meter during the heat treatment; A steel sheet heat treatment apparatus comprising: means for finely adjusting a tensile force during the heat treatment based on a comparison between the elongation target value and the measured elongation value.

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