JPH10109102A - Temper rolling method and processing method by leveler working of metastable austenitic stainless steel strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the mechanical property of a steel strip clear the target value by measuring the quantity of strain-induced martensite of the stainless steel strip after temper rolling and adjusting the elongation percentage of the steel strip so that the quantity of strain-induced martensite becomes the target value. SOLUTION: The metastable austenitic stainless steel strip 41 is temper rolled with a mill 43. The quantity α' of strain-induced martensite of the steel strip 41 is measured with an α' weighing/measuring sensor 61 which is provided between the mill 43 and a tension reel 45. There is strong correlation between the quantity α' of martensite and the mechanical property of the steel strip 41. And, there is strong correlation between the quantity α' of martensite and the elongation percentage of the steel strip 41. The target α' is preliminarily set with an α' setting device 64 so as to impart a prescribed mechanical property to the steel strip 41. When there is difference between the target α' and a measured value α', the elongation percentage of the steel strip 41 is controlled so that the difference becomes zero. The elongation percentage is controlled by adjusting the rolling force and tension of the steel strip 41. The rolling force is adjusted with a pressure controller 71 and the tension is adjusted with tension controllers 75a, 75b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temper rolling method and a leveler processing method for a metastable austenitic stainless steel strip, and more particularly to a temper rolling of a metastable austenitic stainless steel strip for controlling the amount of work-induced martensite. And a leveler processing method.

[0002]

2. Description of the Related Art Conventionally, metal strips such as ordinary steel, special steel including stainless steel, and various high alloys have been shaped by heat treatment rolling or leveling to improve flatness. I have.

FIG. 7 is a conceptual diagram showing a configuration of a temper rolling mill as a typical prior art. The metal strip 1 is temper-rolled between a pair of upper and lower work rolls 2 and 3. The metal strip 1 is continuously supplied between the upper and lower work rolls 2 and 3 via the entrance-side deflector roll 6 while being rewound from the payoff reel 5 on which the metal strip coil 4 is mounted. The metal strip 1 after the temper rolling is wound on a tension reel 10 via a delivery-side deflector roll 9. Upper and lower work rolls 2, 3
Are respectively supported by upper and lower backup rolls 14 and 15 having a larger diameter.

[0004] The rotation speeds of the input side deflector roll 6 and the output side deflector roll 9 are respectively measured by pulse generators 12 and 13 with built-in high-speed counters, and output to a calculator (not shown). In the arithmetic unit, the elongation rate of the metal strip 1 is obtained. The rolling cylinder 16 displaces the lower work roll 3 and the lower backup roll 15 so as to be able to move up and down, and applies a rolling force to the metal band 1. The elongation rate of the metal strip 1 is controlled by controlling the rolling force of the rolling cylinder 16. Also, upper and lower work rolls 2, 3,
The payoff reel 5 and the tension reel 10 are driven to rotate by independent motors, respectively, and the number of rotations is controlled between the payoff reel 5 and the upper and lower work rolls 2 and 3 and between the upper and lower work rolls 2 and 3 and the tension reel 10.
Is controlled so that a predetermined tension is generated in each of the metal strips 1 between them. Generally, in the temper rolling, a method called a wet skin pass in which a water-soluble temper rolling oil is roughly interposed between the metal strip 1 and the upper and lower work rolls 2 and 3 and which is called a skin pass rolling is used. There is a method called a dry skin pass that does not use it at all. The temper rolling conditions such as the target elongation and the presence or absence of the temper rolling oil are determined according to the required product specifications of the metal strip 1.

FIG. 8 is a conceptual diagram showing a configuration of a tension leveling facility which is a typical prior art of a leveler processing facility. The tension leveling of the metal strip 1 is performed by connecting the front end of the subsequent metal strip unwound from the metal strip coil 4 set on the pay-off reel 21 to the rear end of the preceding metal strip and successively rewinding as a continuous metal strip 1. , A pinch roll or deflector roll 22a, a deflector roll 22c,
Pass line rolls 24a, 24a for guiding the metal strip 1;
.., The entrance bridle roll 25a, the tension leveling roll unit 29 and the support rolls 29a, 29b before and after it, the exit bridle roll 25b, the pass line rolls 24b, 24b,.
This is performed by successively passing through d and the like, successively passing the sheet, and winding the sheet on the tension reel 30.

[0006] In the tension leveling, the shape is corrected by applying a large tension between the bridle rolls 25a and 25b to the metal band 1 while generating a predetermined target elongation rate for the metal band 1. That is, in the tension leveling roll unit 29, the elongation and the shape correction of the metal strip 1 continuously passed are performed, and the metal strip 1 is warped in the width direction and the longitudinal direction. Correction is performed. In addition to the above-mentioned tension leveling, there is also a shape correction method called roller leveling as the leveler processing method. In any case, the shape correction of the metal strip 1 that is continuously passed is performed.

[0007] In a metal band maker, for example, a steel maker, the shape of the metal band 1 is corrected by the temper rolling method or the leveler processing method in the final manufacturing process, and the product is shipped as a product. The precision of the flatness of the metal strip 1 is improved. The metal strip 1 to be shipped as a product is required to have not only high precision of flatness but also high precision of mechanical properties such as resilience, proof stress and tensile strength. For example, metastable austenitic stainless steel strips represented by SUS301 and SUS304, which are frequently used in the field of automotive materials (hereinafter, referred to as SUS301)
In the case of “steel strip”, when subjected to room-temperature processing such as temper rolling and leveler processing, a work-induced martensite (hereinafter sometimes abbreviated as “α ′”) phase is generated. It is known that the mechanical properties of a steel strip are greatly affected by the amount of α '.

The formation of the α 'phase is affected by factors such as the composition of the material, the temperature during rolling, the rolling reduction, and the rolling speed. In particular, the temper rolling or leveler processing is the last production step in a steel maker, and thus greatly affects the mechanical properties of a steel strip to be shipped. However, in the conventional steel strip temper rolling method and leveler processing method,
A technique for controlling the α ′ content of a steel strip online so as to be able to hit a target mechanical property has not been established. Therefore, in order to obtain a steel strip having flatness and mechanical properties agreed with the user, the steel maker determines a target elongation rate to be targeted based on past data, that is, operation results, and determines the target elongation rate and the target elongation rate. Temper rolling or leveler processing of the metastable austenitic stainless steel strip is performed so that the measured elongation rate of the steel strip matches.

[0009] The steel maker grasps the mechanical properties of the steel strip by temper rolling or leveler processing, cutting off a part of the steel strip coil as a test piece, and measuring the mechanical properties of the test piece. Is going. in this way,
Since it is difficult to grasp the mechanical properties over the entire length of the steel strip, one end of the steel strip where the mechanical properties are the most inferior is employed as a test piece. If the mechanical properties of the test piece are out of the allowable range agreed with the user, the steel strip coil is subjected to another heat treatment and then temper rolling or leveler processing, or the test value level is low. Processed as another rank product.

[0010]

In the conventional temper rolling method and leveler processing method described above, since the original purpose is shape correction and not the control of the amount of α ', the metastable austenitic stainless steel is used. The mechanical properties of the band may deviate from the target value, and the product yield may be reduced. In addition, since the material control is not performed online, the mechanical properties become evident only after the temper rolling or the leveler processing is completed. Yield may be significantly reduced. In addition, since the mechanical properties of the entire length of the steel strip are estimated from a part of the test pieces, there is a possibility that the steel strip may flow out including a test value defective portion that does not satisfy a product requirement specification negotiated with a user. is there.

An object of the present invention is to measure and control the amount of work-induced martensite with high accuracy over the entire length, and to control mechanical properties with high accuracy so as to be within a target range. It is an object of the present invention to provide a passable rolling method and a leveler processing method for a metastable austenitic stainless steel strip that can be performed.

[0012]

According to a first aspect of the present invention, there is provided a method for temper rolling a metastable austenitic stainless steel strip, wherein at least the amount of work-induced martensite of the stainless steel strip after temper rolling is measured. A temper rolling method for a metastable austenitic stainless steel strip, characterized in that the elongation of the stainless steel strip is controlled so that the measured value becomes a predetermined target value of the amount of work-induced martensite. According to the present invention, the amount of work-induced martensite of the metastable austenitic stainless steel strip is measured at least after temper rolling. For example, by disposing a sensor for non-contact measurement of the α ′ amount of the steel strip continuously passed through the temper rolling mill between the temper rolling mill and the tension reel, the temper rolling after temper rolling is performed. The α ′ amount can be accurately and quickly measured and grasped over the entire length of the steel strip. As a result, for example, it is possible to prevent the steel strip including the test value defective portion that does not satisfy the product requirement specification agreed with the user from flowing out. In addition, temper rolling is the final step in steel manufacturers, and since the α 'amount has a strong correlation with the mechanical properties of the stainless steel strip, quality assurance over the entire length of the steel strip shipped after temper rolling is ensured. be able to. Further, the elongation percentage of the steel strip is controlled so that the measured value of the α ′ amount becomes a predetermined target value of the α ′ amount. Since the elongation of the steel strip has a direct effect on the α ′ amount of the steel strip, the α ′ amount of the steel strip after temper rolling is accurately matched with a predetermined α ′ amount target value. be able to. This makes it possible to obtain the stainless steel strip having the α ′ amount that coincides with the target value, that is, the stainless steel strip having the desired mechanical properties with high reliability. Improvement can be achieved.

According to a second aspect of the present invention, the elongation rate of the stainless steel strip is controlled when the tempering rolling force of the temper rolling mill is equal to or less than a predetermined maximum rolling force. When the tempering rolling force of the temper rolling mill exceeds a predetermined maximum rolling force, the tempering rolling is performed by controlling the tension of the stainless steel strip while maintaining the tempering rolling force at the maximum rolling force. It is characterized by. According to the present invention, the elongation rate of the steel strip is controlled by controlling the tempering rolling force when the tempering rolling force is equal to or less than a predetermined maximum rolling force. That is, as compared with the target value of the α ′ amount, the tempering rolling force is controlled so that the elongation rate is increased when the measured value is smaller, and conversely, when the measured value is larger, the elongation rate is decreased. The rolling force is controlled so as to reduce. Since the tempering rolling force directly affects the elongation of the steel strip, the elongation can be controlled with good responsiveness. Further, when the tempering rolling force exceeds a predetermined maximum rolling force, the elongation control is performed by controlling the tension applied to the steel strip while maintaining the tempering rolling force at the maximum rolling force. . In a steel strip to which a constant rolling force has been applied, increasing the tension applied to the steel strip increases the elongation. For example, even when a tempering rolling force exceeding the limit in the equipment specifications of the temper rolling mill is required, a predetermined elongation can be obtained by controlling the tension applied to the steel strip. Therefore, the control range of the α ′ amount can be greatly expanded.

According to a third aspect of the present invention, in the method for leveler processing a metastable austenitic stainless steel strip, at least the amount of work-induced martensite of the stainless steel strip after the leveler processing is measured, and the measured value is obtained. A leveler processing method for a metastable austenitic stainless steel strip, wherein the elongation percentage of the stainless steel strip is controlled so as to be a target value of a predetermined amount of work-induced martensite. According to the present invention, the α 'content of the metastable austenitic stainless steel strip is measured after leveler processing. For example, by arranging a sensor for measuring the amount of α ′ between the roll unit performing the leveling process and the tension reel, the α ′ amount after the leveling process is accurately and quickly measured over the entire length of the steel strip, You can figure out. Further, the elongation percentage of the steel strip is controlled so that the measured value of the α ′ amount becomes a predetermined target value of the α ′ amount. The control of the elongation is performed by, for example, controlling the amount of pressing of the roll unit, the difference in the passing speed of the steel strip to be passed before and after the roll unit, and the like in accordance with the measured value of the α ′ amount. . Since the α ′ amount of the steel strip is greatly affected by a change in the elongation percentage of the steel strip, the α ′ amount of the steel strip after the leveler processing is controlled by controlling the elongation percentage of the steel strip. ′ Can exactly match the target value. This makes it possible to obtain a steel strip having an α ′ amount consistent with a target value, that is, the steel strip having desired mechanical properties with high reliability. Can be improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a temper rolling mill 42 capable of suitably controlling the amount of martensite induced by processing of a metastable austenitic stainless steel strip 41 according to an embodiment of the present invention. FIG. 2 is a system diagram showing a configuration. The temper rolling equipment 42 includes a mill main body 43 of a temper rolling mill that lightly rolls a metastable austenitic stainless steel strip (hereinafter, may be abbreviated as “steel strip”) 41 and a mill main body 43 Reel 44 to be supplied to the mill and the mill body 43
Tension reel 45 for winding the steel strip 41 conveyed from
And an entrance deflector roll 46 provided between the mill body 43 and the payoff reel 44 for guiding the steel strip 41 conveyed from obliquely below to a substantially horizontal pass line.
An output deflector roll 47 for transporting the steel strip 41 conveyed from the substantially horizontal pass line to the tension reel 45 disposed diagonally below, and a mill body 43 provided between the tension reel 3 and the tension reel 45. And an α ′ amount measurement sensor 61 provided between the output side deflector roll 47 and the output side deflector roll 47. In the temper rolling mill 42, the steel strip 41
Is usually passed only one pass in the direction indicated by the arrow 42a.

The mill main body 43 is, for example, a quadruple temper rolling mill, and includes four rolls symmetrically arranged so as to sandwich the steel strip 41 up and down, and a rolling cylinder 50.
The upper and lower work rolls 48 are respectively in contact with the four surfaces of the steel strip 41 in the thickness direction (vertical direction in FIG. 1).
a, 48b and upper and lower backup rolls 49a, 49 supporting the upper and lower work rolls 48a, 48b, respectively.
b. These work rolls and backup rolls are driven to rotate by independent drive motors. In FIG. 1, only the drive motor 54 of the upper work roll 48a is shown for convenience of illustration. Roll-down cylinder 50
Lowers the lower work roll 48b and the lower backup roll 49b, which are disposed so as to be displaceable in the thickness direction of the steel strip 41 (vertical direction in FIG. 1), thereby lowering the rolling force applied to the steel strip 41. Can be adjusted.

In the temper rolling equipment 42 having such a mill body 43, the steel strip 41 is temper rolled, for example, as follows. First, the steel strip 41 is mounted on the payoff reel 44 in a coil state. The coil 41 a mounted on the payoff reel 44 is rotated and driven by the payoff reel drive motor 53 together with the payoff reel 44 to be rewound. The steel strip 41 unwound from the coil 41a is conveyed in the direction of the arrow 42a via the entry-side deflector roll 46, and the upper and lower work rolls 48a, 48b of the mill main body 43.
It is passed between the boards. The rolling force between the upper and lower work rolls 48a and 48b is initially set by the rolling cylinder 50 so that the steel strip 41 is given a predetermined elongation. Therefore, the shape (flatness) of the steel strip 41 is corrected by the passing plate.

The steel strip 41 passed between the upper and lower work rolls 48a and 48b is transported to the tension reel 45 via the output side deflector roll 47, and the leading end of the steel strip 41 is locked to the tension reel 45. The steel strip 41 having the leading end portion locked to the tension reel 45 is rotated by a tension reel drive motor 55 to drive the tension reel 45.
It is wound up. After the start of winding, the rotation speed of each roll drive motor and each of the reel drive motors 53 and 55 is increased, and accordingly, the passing speed of the steel strip 41 is increased to a predetermined speed. The threading speed is controlled by a threading speed control device 78, and is kept constant during temper rolling of the steel strip 41.

The pay-off reel 44, the upper and lower work rolls 48a, 48b, and the tension reel 45 are rotated by a pay-off reel drive motor 53, a roll drive motor 54, and a tension reel drive motor 55, which are controlled by respective control devices described later. When driven, a predetermined tension is applied to the steel strip 41. That is,
In the temper rolling equipment 42, the threading speed V of the steel strip 41 is:
A threading speed control device 78 that controls the rotation speed of a work roll drive motor 54 that rotationally drives the work roll 48a.
It is controlled by a sheet passing speed control device that controls the rotation speed of another work roll drive motor (not shown).

The payoff reel drive motor 53 controls the tension so that the tension applied to the steel strip 41 between the payoff reel 44 and the upper and lower work rolls 48a and 48b matches the tension set value T by the tension setting device 73. It is controlled by the device 75a. That is, the tension control device 75a controls the steel strip 41 so that the tension generated in the steel strip 41 by the difference between the rotation speed of the upper and lower work rolls 48a and 48b of the mill body 43 and the rotation speed of the payoff reel 44 matches the tension set value T. The payoff reel drive motor 53 is controlled by compensating for a decrease in the diameter of the coil 41a due to the rewinding of the band 41. The tension control device 75b includes a tension control device 75a.
Similarly to the above, the increase in the diameter of the coil 41b due to the winding of the steel strip 41 around the tension reel 45 is compensated, and the tension applied to the steel strip 41 between the upper and lower work rolls 48a, 48b and the tension reel 45 is reduced. , Tension setting device 73
The tension reel drive motor 55 is controlled so as to match the tension set value T according to. The steel strip 41 that has been temper-rolled to the vicinity of the rear end of the steel strip 41 is wound on a tension reel 45, then pulled out of the tension reel 45, inspected, packed, and shipped.

The amount of work-induced martensite (α ′) that affects the material of the steel strip 41 is controlled by controlling the elongation of the steel strip 41. The control of the elongation rate of the steel strip 41 is as follows.
This is performed by controlling the rolling force by the rolling cylinder 50 and the tension applied to the steel strip 41. The α ′ amount measuring sensor 61 is provided at a predetermined interval from the surface of the steel strip 41, and can measure the α ′ amount of the steel strip 41 with high accuracy. The detailed description will be described later.

Next, the electrical configuration of the temper rolling equipment 42 will be described with reference to FIG. The control target changeover switch 66 is a switch that switches between a material control mode in which the α ′ amount of the steel strip 41 is controlled to control the material and a shape control mode in which the shape of the steel strip 41 is corrected based on a manufacturing command described later. . The rolling / tensile changeover switch 68 switches between a rolling force control mode in which the elongation rate of the steel strip 41 is controlled by controlling the rolling force and a tension control mode in which the elongation rate control is performed by controlling the tension. Switch. In the present embodiment, the control mode at the start of the temper rolling is initially set to the rolling force control mode.
8a and the terminal 68b are electrically connected.

When the temper rolling is performed in the material control mode, the terminals 66a and 66b of the switch 66 are electrically connected. The output of the α ′ amount measurement sensor 61 is provided to an α ′ amount calculation device 62. In the α ′ amount calculating device 62, the output of the α ′ amount measurement sensor 61 is corrected as an error due to the influence factors of the thickness, tension and temperature of the steel strip 41 at the installation position of the sensor 61, to obtain the measured α ′ amount. The calculated value is output to the α 'amount comparator 63. Further, the measured α ′ amount is also sent to a display recording device (not shown), and the measured α ′ amount is also transmitted together with the position information of the steel strip 41 at which the measured α ′ amount was measured (for example, the length in the longitudinal direction from the tip end of the steel strip 41). It is displayed and recorded on a display recording device.

In the α ′ amount setting device 64, a target value of the α ′ amount corresponding to the desired mechanical property is set in advance based on the correspondence between the α ′ amount and the mechanical property obtained in advance.
The target α ′ amount, which is the target value of the α ′ amount, is calculated by the α ′ amount comparator 6
3 is output. The α ′ amount comparator 63 compares the measured α ′ amount output from the α ′ amount calculation device 62 with the target α ′ amount, and obtains a deviation Δα ′ amount. The obtained deviation Δα ′ is output to the converter 132, and is multiplied by the coefficient of influence of the α ′ on the elongation of the steel strip 41 to be converted into the elongation deviation Δε1. The elongation rate deviation Δε1 is output to the converter 130 via the control target changeover switch 66. In the converter 130, the elongation rate deviation Δε1 is converted into a rolling force deviation ΔP by multiplying the coefficient of influence of the elongation rate of the steel strip 41 on the rolling force applied to the steel strip 41. After the conversion, the rolling force deviation ΔP is output to the rolling force adder 69 via the rolling / tension switch 68. In the rolling force adder 69, the rolling force set value P determined by the rolling force setting device 70 is added to the rolling force deviation ΔP, and a rolling force command value P1 is obtained. The rolling force command value P1 is output to the rolling force control device 71. The rolling force control device 71 applies the command rolling force P1 to the steel strip 41 based on the rolling force command value P1.
Is controlled so that the pressure is applied. The rolling cylinder 50 is controlled by the rolling force control device 71 so that the output from the load cell 50a having a strain gauge, that is, the measured rolling force value, is supplied to the rolling cylinder 50 so that the rolling force command value P1 matches. This is done by adjusting the amount of oil. In the temper rolling facility 50, the temper rolling reduction force is controlled so that, when the measured value is smaller than the target value of the α ′ amount, the elongation is increased, and conversely, the measured value is smaller. If it is large, the rolling force is controlled so that the elongation becomes small.

When the elongation rate control is performed in the tension control mode, the terminals 68a and 68c are electrically connected. At this time, the rolling-down force control device 71 sets the rolling-down cylinder 5 so that the rolling-down force becomes the maximum rolling force described later.
Control 0. Further, the rolling force deviation ΔP is output to a subtractor 131 via a rolling / tension changeover switch 68.
In the subtracter 131, a rolling force excess deviation ΔP ′ described later is obtained based on the rolling force deviation ΔP. The operation value is output to converter 133. The converter 133 multiplies the rolling force excess deviation ΔP ′ by the influence coefficient of the tension on the rolling force, and converts the rolling force excess deviation ΔP ′ into a tension deviation ΔT. After the conversion, the tension deviation ΔT is calculated by the tension adder 72.
Output to In the tension adder 72, the tension deviation ΔT
The tension set value T by the tension setting device 73 is added, and the tension command value T1 is calculated. The tension command value T1 is output to each of the tension controllers 75a and 75b. Each of the tension control devices 75a, 75b includes upper and lower work rolls 48a, 48b.
Between work and payoff reel 44 and upper and lower work rolls 4
8a, 48b and the tension reel 45, the steel strip 4
The respective rotational speeds of the payoff reel drive motor 53 and the tension reel drive motor 55 are controlled such that the measured value of the tension applied to each of the motors 1 and 1 matches the tension command value T1. The measured value of the tension can be derived from the load applied to the inlet and outlet deflector rolls 46 and 47 detected by a load cell (not shown) having a strain gauge.

When the temper rolling is performed in the shape control mode, the terminals 66a and 66c of the switch 66 to be controlled are electrically connected. Steel strip 41
Is measured by the elongation percentage calculator 77. That is, the inlet and outlet deflector rolls 46, 4
7 are measured by the pulse generators 76a and 76b with built-in high-speed counters and output to the elongation ratio calculating device 77. The elongation percentage calculating device 77 calculates the elongation percentage of the steel strip 41 from the result of the comparison operation of the respective rotational speeds. The calculated elongation percentage is output to the elongation percentage comparator 79 as a measured elongation percentage. Elongation rate comparator 79
In the above, the measured elongation percentage is compared with an elongation percentage set value ε preset by the elongation percentage setting device 67 to calculate an elongation percentage deviation Δε2. The elongation rate deviation Δε2 is output to the converter 130 via the control target changeover switch 66. The elongation ratio deviation Δε2 input to the converter 130 is converted into a rolling force deviation ΔP, and the rolling / tension changeover switch 68
Is output to the rolling force adder 69 or the subtractor 131 via the control unit, but the control content is the same as that in the material control mode described above, and the description is omitted.

In addition, the temper rolling equipment 42 is provided with a temper-conditioning pressure oil (hereinafter, may be abbreviated as "pressure-conditioning oil") not shown. The pressure adjusting oil injection device has a tank for storing the pressure adjusting oil, a pump for pumping the pressure adjusting oil, and a nozzle for injecting the pressure adjusting oil to the steel strip 41. The pressure adjusting oil injection device is disposed, for example, near the entry side of the upper work roll 48a of the mill body 43 so as not to hinder the rotation of the upper and lower work rolls 48a, 48b and the upper and lower backup rolls 49a, 49b and the movement of the steel strip 41. Is established. By injecting the pressure regulating oil into the steel strip 41 during the temper rolling, the frictional force acting between the steel strip surface and the upper and lower work rolls 48a, 48b can be reduced, so that the pressure regulating oil is not injected. As compared with the case, the energy consumed as friction loss is reduced, and the power required for temper rolling can be reduced. Although the surface gloss of the steel strip 41 can be adjusted by adjusting the presence, amount, type, etc. of the pressure regulating oil to be injected, the pressure regulating oil used in the temper rolling is small. By injecting steel strip 41
Does not change.

FIG. 2 is a flow chart for explaining the method of temper rolling of the metastable austenitic stainless steel strip 41. In step d1, the steel strip 41 is mounted on the payoff reel 44. At step d2, a production command is issued. The contents of the manufacturing command include material coil information, product required specifications such as dimensions, shapes, and mechanical properties, and control categories such as material control mode or shape control mode. In step d3, temper rolling conditions are set based on the production command. The conditions to be set include the control category, the target α 'amount, the elongation rate set value ε, the tension set value T, the rolling force set value P, the maximum rolling force set value P _max , the passing speed V, and each influence coefficient. is there. As the target α ′ amount, an α ′ amount corresponding to a desired mechanical property is set. The elongation rate setting value ε is set to an elongation rate (for example, 1%) necessary for correcting the shape of the steel strip 41. The threading speed V, the rolling force set value P, and the tension set value T are such that the set elongation rate ε is
It is set to an optimized value so as to be given to 1.
The maximum rolling force set value _Pmax is set to a rolling force smaller than the critical rolling force in the equipment specifications of the mill main body 43. In addition,
The rolling force allowable deviation ( _Pmax- P) is calculated and set together with these set values.

In step d4, temper rolling is started. When the temper rolling is started, the payoff reel 44, the tension reel 45, and the upper and lower work rolls 4 are set in accordance with the set values and the threading speed set in step d3.
The rotation speeds of 8a and 48b and the rolling force by the rolling cylinder 50 are controlled, respectively.

In step d5, it is determined whether or not the temper rolling control is in the material control mode based on the production command. If this determination is affirmative, the process proceeds to step d6. In step d6, the α ′ amount of the steel strip 41 is measured. The measured value of the α ′ amount of the steel strip 41 is the α ′ amount measurement sensor 6
1 is calculated by the α ′ amount calculating device 62 based on the output of the first and the calculated α ′ amount. In step d7,
The calculated measured α ′ amount is compared with a target α ′ amount set in advance in step d3, and a deviation Δα ′ amount as the calculation result is calculated. Step d8
Then, the amount of the deviation Δα ′ is converted into an elongation percentage deviation Δε1. The conversion is performed by multiplying the amount of deviation Δα ′ by the influence coefficient of the amount of α ′ on the elongation of the steel strip 41. After the conversion, the process proceeds to step d11.

If the determination in step d5 is negative, that is, if the shape control of the steel strip 41 is performed in the temper rolling facility 42, the process proceeds to step d9. In step d9, the elongation percentage of the steel strip 41 is measured. The elongation percentage measurement value is obtained by the elongation percentage calculator 77 based on each output of each of the pulse generators 76a and 76b. In step d10, the measured elongation percentage is obtained,
The preset elongation percentage set value ε is compared and calculated,
The elongation rate deviation Δε2 as the calculation result is calculated. After the calculation, the process proceeds to step d11.

In step d11, the elongation rate deviation Δε
1 or Δε2 is converted to a rolling force deviation ΔP. The conversion is based on the steel strip 4 with respect to the rolling force applied to the steel strip 41.
This is performed by multiplying the elongation rate deviation Δε1 or Δε2 by the influence coefficient of the elongation rate of 1. After the conversion, the process proceeds to step d12. In step d12, the obtained rolling force deviation ΔP is compared with the rolling force allowable deviation (P _max −P) set in step d3, and the rolling force deviation Δ
It is determined whether or not P is equal to or less than the rolling force allowable deviation ( _Pmax- P). If this judgment is affirmative, step d1
Proceed to 3. In step d13, the rolling force set value P is added to the rolling force deviation ΔP, and the calculation result, that is, the rolling force command value P1 is obtained. After the calculation, the process proceeds to step d14. At step d14, the rolling force control is performed. The rolling force control is performed so that the measured value of the rolling force applied to the steel strip 41 matches the rolling force command value P1.
This is performed by controlling the pressure reduction cylinder 50.

If the determination in step d12 is negative, the process proceeds to step d15. In step d15,
The rolling cylinder 50 is controlled such that the rolling force applied to the steel strip 41 becomes the maximum rolling force _Pmax . In step d16, the rolling force deviation ΔP is added to the rolling force set value P.
Is subtracted from the maximum rolling force set value P _max to obtain the rolling force excess deviation ΔP ′.
In step d17, the rolling force excess deviation ΔP ′ is converted into a tension deviation ΔT. The conversion is performed by multiplying the rolling force excess deviation ΔP ′ by a predetermined influence coefficient as described above. In step d18, the tension set value T set in step d3 is added to the tension deviation ΔT.
Is added to obtain the tension command value T1. After the calculation, the process proceeds to step d19. At step d19, tension control is performed. The tension control is performed by controlling the rotation speeds of the pay-off reel drive motor 53 and the tension reel drive motor 55 so that the measured value of the tension applied to the steel strip 41 matches the obtained tension command value T1. . In step d20, it is determined whether the coil 41b has been wound up to the coil end. If this determination is negative, the process returns to step d4, and the above processing is repeated until the determination becomes positive. If the determination in step d20 is affirmative, the process proceeds to step d21 and the temper rolling of the steel strip 41 ends.

As described above, in the present embodiment, in the material control mode, the measured α ′ amount of the steel strip 41 derived from the output of the α ′ amount measuring sensor 61 and the α ′ amount setting device 64 The α ′ amount control of the steel strip 41 is performed so that the difference from the preset target α ′ amount, that is, the deviation Δα ′ amount becomes zero. The α ′ amount control is performed by controlling the elongation rate of the steel strip 41, and the elongation rate is controlled by controlling the rolling force and the tension applied to the steel strip 41. The α ′ amount of the steel strip 41 has a strong correlation with the elongation rate of the steel strip 41, and the elongation rate is directly affected by the rolling force applied to the steel strip 41. By controlling, the α ′ amount of the steel strip 41 can be controlled with good responsiveness. A steel strip 4 to which a certain rolling force is applied
In (1), when the tension applied to the steel strip 41 is increased, the elongation percentage is proportionally increased. Therefore, by controlling the tension applied to the steel strip 41, the steel strip 41 is controlled.
Can be controlled. In the above-described embodiment, when the rolling force applied to the steel strip 41 exceeds the predetermined maximum rolling force _Pmax , the steel strip 41 is applied to the steel strip 41 while the maximum rolling force is applied. The tension is controlled so that the measured α ′ amount matches the target α ′ amount. Therefore, even when a rolling force exceeding the predetermined maximum rolling force _Pmax is required for the α ′ amount control, a predetermined α ′ amount can be obtained by the tension control. Thus, the failure of the mill body 43 can be prevented, and the control range of the α ′ amount can be greatly expanded as compared with the case where the α ′ amount control is performed by the rolling force alone. In the case of the shape control mode, temper rolling can be performed so that the steel strip 41 has a predetermined elongation. Thus, the temper rolling equipment 42
Since the steel strip 41 is configured to be controllable in each control mode, material control or shape control of the steel strip 41 can be accurately performed.

Further, in the temper rolling equipment 42 shown in FIG. 1, the material control is performed on the downstream side of the mill main body 43, that is, α ′ provided between the mill main body 43 and the tension reel 45.
Although it is performed by feedback control by taking in the output of the quantity measurement sensor 61, it is further arranged upstream of the mill main body 43, that is, disposed between the payoff reel 44 and the mill main body 43 as another embodiment. The steel strip 41 having desired mechanical properties can be obtained by so-called feedforward control in which the elongation is controlled based on the measured α ′ amount output from the α ′ amount measurement sensor described above. Further, the material control may be a control in which the feedback and the feedforward control are distributed in a predetermined ratio and combined in addition to the control by the feedback or the feedforward control alone. As a result, compared to the case of performing the α ′ amount control by the feedback or feedforward control alone, α ′
The amount can be controlled.

FIG. 3 is a system diagram showing a configuration of a tension leveling facility 81 according to another embodiment of the present invention, which can suitably control the amount of work-induced martensite of the metastable austenitic stainless steel strip 41. . The tension leveling equipment 81 basically includes a tension leveling roll unit (hereinafter sometimes abbreviated as “roll unit”) 82 for correcting the shape of the metastable austenitic stainless steel strip 41 and the steel strip 41 to the roll unit 82. It includes a payoff reel 83 to be supplied, a tension reel 84 for winding the steel strip 41 conveyed from the roll unit 82, and an α ′ amount measurement sensor 61.

Further, between the payoff reel 83 and the roll unit 82, the first deflector roll 85 on the entry side is moved from the payoff reel 83 toward the roll unit 82.
a, a tension meter roll 86 for detecting the tension of the steel strip 41, the second and third deflector rolls 85b, 8 on the entry side.
5c, entrance pass line roll 87 for guiding steel strip 41,
87,..., An entrance bridle roll 88 and a support roll 89 are sequentially arranged. Between the roll unit 82 and the tension reel 84, from the roll unit 82 toward the tension reel 84, the output side support roll 90, the output side bridle roll 91, the output side pass line rolls 92, 92,. Deflector rolls 93 are arranged in order. Further, in the threading path of the steel strip 41 up to the entry side bridle roll 88, for example, a welder 140 for connecting the steel strip 41, a side trimmer for performing side trimming of the steel strip 41, and a threading strip of the steel strip 41 are provided. Use a looper for continuous sheet passing without stopping, or a cleaning liquid (for example, an emulsion cleaning liquid of about 95% water and about 5% cleaning oil (kerosene, surfactant, etc.) in the roll unit 82). And a ringer roll, a hot dryer, and the like necessary for performing the tension leveling of the steel strip 41.
On the output side further from the output side deflector roll 91, a pinch roll, a shear 141 for shearing the steel strip 41 in coil units and winding it on a tension reel 84 are arranged. The roll unit 82 having various configurations and combinations of leveling rolls is incorporated as an existing unit according to the strength of the steel strip 41 to be tension-leveled and the degree of demand for shape correction thereof. I have.

Next, a method of controlling the tension leveling of the steel strip 41 will be described below. Although the steel strip 41 continuously passed through the tension leveling equipment 81 is subjected to tension leveling in a state where a predetermined tension is applied, actually performing tension leveling is performed by:
Fig. 3 shows the elongation control center section shown in Fig. 3.
The tension applied to the steel strip 41 is controlled separately from a tension control entrance section and a tension control exit section in addition to the elongation rate control central section.

In the tension control entry section, a predetermined tension generated between the pay-off reel 83 and the entry bridle roll 88 is applied to the steel strip 41 so that the steel strip 41 does not loosen, and the tension is reduced. It is controlled so that it is wound around and guided by the side bridle roll 88 without any trouble. On the other hand, in the tension control output section, a predetermined tension generated between the output side bridle roll 91 and the tension reel 84 is applied to the steel strip 41, and the elongation control is performed on the steel strip 41 in the elongation control center section. The steel strip 41 is controlled so as to be wound around the tension reel 84 without slack to the extent that the strip 41 does not deform or buckle. Tension control devices in such entry and exit tension control sections can be implemented according to typical prior art. In the present invention, the tension control device is not limited to a specific prior art, and a detailed description of each tension control section will be omitted, as long as the control purpose described above is achieved.

In the elongation rate control central section, unlike the tension control in the entrance and exit tension control sections described above, the tension leveling equipment 81 is used.
A predetermined elongation rate is generated in the steel strip 41 based on the overall commanded threading speed V of the steel strip 41 and in a state in which much higher tension is applied to the steel strip 41 than to the entry side and the exit side. Thus, the elongation percentage of the steel strip 41 is controlled. That is, between the bridle rolls 88 and 91 disposed on the entrance side and the exit side, respectively, with the roll unit 82 and the support rolls 89 and 90 disposed before and after the roll unit 82 as the center, the tension control sections on the entrance side and the exit side are different. Unlike the independent elongation control sections, both bridle rolls 8
The steel strip 41 which is continuously passed at a predetermined threading speed by applying a large tension generated between the steel strips 8 and 91 to the steel strip 41 to form a predetermined plastic elongation rate is set. Control is performed so that correction or material control is performed.

The method of controlling the elongation rate of the elongation rate control central section using the entrance side and exit side bridle rolls 88 and 91 will be described in more detail below. Generally, such bridging rolls 88,
ID (Indi) which drives each 91 independently to generate a speed difference (torque difference) between the entrance side and the exit side bridle rolls.
vidual drive) method and S shown in FIG. 3 and described below.
D (SpeedDeferential Drive) method.

Each of the entrance side and exit side bridle rolls 88 and 91 shown in FIG. 3 employs a differential bridle system in which the entrance side and the exit side are connected by one drive shaft.
Each of the bridle rolls 88 and 91 has a power distribution device 96 on the inlet side and a power distribution device 96 on the outlet side for distributing torque according to the load.
97 are arranged. An elongation control differential 98 of the steel strip 41 having a built-in differential gear is connected and arranged between one drive shaft (line drive shaft) connecting the input side and the output side. By driving the elongation rate control differential 98, the entrance bridle roll 88 is driven.
The structure is such that a more positive speed difference is generated in the outgoing bridle roll 91. In addition, the entirety of the power distribution devices 96 and 97 on the entrance side and the exit side is composed of a bridle main drive motor 99.
In addition to this drive, the elongation rate control motor 100, which is separately arranged, applies a specific rotation speed, which will be described later, to the elongation rate control differential device 98, so that the outgoing bridle roll 91 is moved inward. The bridle roll 88 is rotated at a different speed.

More specifically, the entrance side and exit side bridle rolls 88, 91 are respectively provided with entrance side and exit side power distribution devices 96, 97 connected by drive shafts, respectively. The devices 96 and 97 are connected with one drive shaft via an elongation control differential 98. Further, a bridle main drive motor 99 is connected to the one drive shaft. The bridle rolls 88 and 91 are driven and rotated by a bridle main drive motor 99 which is controlled and rotated based on the passing speed command value V. In the drive system of the bridle main drive motor 99,
The passing speed measurement value V ′ and the passing speed command value V of the steel strip 41 detected from the bridle main drive motor 99 by the first pulse generator 102 and converted by the high-speed counter 103 and the passing speed converter 104. By comparison, the rotational speed of the bridle main drive motor 99 with respect to the command value V is corrected and controlled via the speed control device 101. By this correction control mechanism, each bridle roll 88, 91
Is controlled so that the actual passing speed V ′ of the steel strip 41 coincides with the command value V. In the tension leveling equipment 81, the steel strip 41 is passed through one pass in the direction of the arrow 95.

Next, the material control performed on the steel strip 41 passing between the bridle rolls 88 and 91, that is, the α 'amount control will be described. Note that parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. As described above, the amount of α ′ that affects the mechanical properties of the steel strip 41 can be controlled by controlling the elongation of the steel strip 41. In the tension leveling facility 81, the elongation rate of the steel strip 41 is controlled by controlling the difference between the passing speeds of the steel strip 41 in the bridle rolls 88 and 91.

Similar to the temper rolling equipment 42 shown in FIG. 1, the tension leveling equipment 81
When the material control of the steel strip 41 is performed in the above, the terminal 66a and the terminal 66b of the control target changeover switch 66 are electrically connected. The α ′ amount measuring sensor 61 is configured to calculate the α ′
In order to measure the amount, it is provided between the outgoing bridle roll 91 and the tension reel 84 along the threading path of the steel strip 41. The output of the α ′ amount measuring sensor 61 is converted into the α ′ amount by the α ′ amount calculating device 62 as described above, the error is corrected, and the measured α ′ amount is compared with the α ′ amount comparator 63 and the display record (not shown). Output to the device. α '
In the amount comparator 63, the measured α ′ amount and the α ′ amount setting device 64
Is compared with the target α 'amount output from the
The α 'amount is determined. The amount of deviation Δα ′ is calculated by the converter 13
2 is multiplied by the influence coefficient of the amount of α ′ on the elongation rate of the steel strip 41. The calculation result, that is, the elongation rate deviation Δε3, is transmitted to the converter 11 via the control target changeover switch 66.
1 is output.

In the converter 111, the elongation rate deviation Δε3
Is multiplied by the influence coefficient of the elongation rate of the steel strip 41 with respect to the difference between the entry side passing speed at the entry side bridle roll 88 and the exit side passing speed at the exit side bridle roll 91, and the elongation rate control speed deviation ΔV Converted to ₁ . After the conversion, the elongation rate control speed deviation ΔV ₁ is output to the speed adder 112. The elongation rate control speed deviation ΔV ₁ is added to the elongation rate control speed measurement value V ₁ ′ of the steel strip 41 at the outlet bridle roll 91 by the speed adder 112 to calculate the elongation rate control speed command value V _1. Is done. The measured elongation rate control speed V ₁ ′ is
It is a measured value of the exit side passing speed of the steel strip 41 at the exit side bridle roll 91 and is detected by the second pulse generator 114 from the elongation rate control motor 100 and the high-speed counter 11
5 and converted by the control speed converter 116. The elongation rate control speed command value V ₁
Is output to the elongation motor speed controller 113.
The elongation rate motor speed control device 113 determines that the elongation rate control speed V ₁ ′ of the steel strip 41 at the exit bridle roll 91 matches the elongation rate control command speed V ₁ based on the elongation rate control speed command value V _1. The rotation speed of the control motor 100 for elongation is controlled so as to perform the control. This rotation speed is the above-described specific rotation speed. By controlling the rotation speed of each bridle roll 88, 91 in this way, the elongation applied to the steel strip 41 in the elongation control center section is controlled.

In the steel strip 41 to which a constant pushing amount is given by the roll unit 82, the change in the passing speed between the entrance side and the exit side of the roll unit 82 is changed by the steel strip 4
1 greatly affects the elongation. Further, the elongation and the amount of α 'have a strong correlation. As described above, the tension leveling equipment 81 controls the threading speed difference based on the output of the α ′ amount measuring sensor 61 to control the steel strip 41.
Is controlled.

When shape control is performed in the tension leveling equipment 81 based on a manufacturing command, the terminals 66a and 66c of the control target changeover switch 66 are electrically connected. The elongation percentage of the steel strip 41 is calculated by using the elongation percentage calculator 11.
7 is calculated. That is, the measured value V ′ of the passing speed of the steel strip 41 at the entrance bridle roll 88 output from the passing speed converter 104 and the width of the steel strip 41 at the exit bridle roll 91 output from the control speed converter 116. Is compared with the measured elongation rate control speed V ₁ ′ to calculate the measured elongation rate. The measured elongation is output to the elongation comparator 79. In the elongation percentage comparator 79, the measured elongation percentage is compared with an elongation percentage set value preset by the elongation percentage setting device 67, and the result of the comparison operation, that is, the elongation percentage deviation Δε4, is set to the control object switch 66. Via the converter 1
11 is output. In the converter 111, the above-mentioned predetermined influence coefficient is multiplied by the elongation rate deviation Δε4 and converted. The description after the conversion is the same as that of the above-described material control, that is, the case where the elongation rate deviation Δε3 is output to the converter 111, and the description is omitted.

The tension leveling equipment 81 shown in FIG.
In the material control, the α ′ amount measurement sensor 6 disposed downstream of the output side bridle roll 91, that is, between the output side bridle roll 91 and the tension reel 84.
Although it is performed by so-called feedback control by taking in the output of 1, as another embodiment, it is disposed upstream of the entrance bridle roll 88, that is, disposed between the payoff reel 83 and the entrance bridle roll 88. Alternatively, it may be performed by feedforward control that controls the elongation rate based on the measured α ′ amount obtained by taking in the output from another α ′ amount measuring sensor and calculating the output. Further, the material control may be a control in which the feedback and the feedforward control are distributed at a predetermined ratio and combined in addition to the control by the feedback or the feedforward control alone.

FIG. 4 is a flowchart for explaining a method of tension leveling of the metastable austenitic stainless steel strip 41. In step e1, a preparation operation for tension leveling is performed. At step e2, a production command is issued. The contents of the manufacturing command are the same as those shown in FIG. In step e3, a tension leveler condition is set based on the manufacturing command. The conditions to be set are the control category,
The target α 'amount, elongation rate set value ε, threading speed V, and various influence coefficients are included. The target α ′ amount is set to an α ′ amount corresponding to a desired mechanical property. The elongation set value ε
Is set to an elongation percentage (for example, 0.2%) necessary for correcting the shape of the steel strip 41. At step e4, tension leveling is started. At the start of the tension leveling, the bridle main drive motor 99 is set based on the set values and the passing speed set in step e3.
The rotation speed of the elongation control motor 100 is controlled. The rotational speeds of the payoff reel 83 and the tension reel 84 are adjusted so that the steel strip 41 is not loosened in the tension control input side and the tension control output side section so that the steel strip coil 94a, 94a of each coil is wound.
The increase and decrease in the diameter of 94b are compensated and controlled. Steps e5 to e10 correspond to steps d5 to e5 shown in FIG.
This is the same as step d10, and the description is omitted.

At step e11, each step e8, e
Elongation rate deviation Δε3 or Δε4 obtained in 10 is converted to the elongation control speed deviation [Delta] V _1. The conversion means that the coefficient of influence of the elongation rate on the difference between the elongation rate control speed V ₁ ′ at the outgoing bridle roll 91 of the steel strip 41 and the passing speed V ′ at the incoming bridle roll 88 is the elongation rate deviation Δε3 or Δε4. Is multiplied by After the conversion, the process proceeds to step e12. Step e
Elongation control speed instruction value V ₁ at 12 is determined. The elongation rate control speed command value V ₁ is determined by the output side bridle roll 91.
And the control speed deviation ΔV ₁ is calculated by adding the measured value V ₁ ′ of the exit side passing speed of the steel strip 41 in the above. After the calculation, the process proceeds to step e13. In step e13, speed control is performed. The speed control is performed so that the elongation rate control speed V ₁ ′ of the steel strip 41 on the outlet bridle roll 91 matches the calculated elongation rate control speed command value V _1. This is done by controlling In step e14, the coil 94
It is determined whether or not the coil end has been wound around b. If this determination is negative, the process returns to step e4, and the above-described processing is repeated until the determination becomes positive. Step e
If the determination at 14 is affirmative, the process proceeds to step e15, and the tension leveling of the steel strip 41 ends.

As described above, in the present embodiment, in the material control mode, the passing speed of the steel strip 41 of the entrance bridle roll 88 and the steel strip 41 of the exit bridle roll 91 are set.
Is controlled so that the measured α ′ amount of the steel strip 41 matches the target α ′ amount. The difference in the passing speed greatly affects the elongation,
As described above, there is a strong correlation between the elongation and the amount of α '. Therefore, by controlling the speed difference,
The α ′ amount of the steel strip 41 can be controlled with good responsiveness.
The steel strip 41 subjected to the tension leveling in the tension leveling equipment 81 is set so that the α ′ amount accurately measured based on the output of the α ′ amount measurement sensor 61 matches the preset target α ′ amount. As a result, the steel strip 41 having the desired amount of α 'can be obtained with high reliability. Further, in the case of the shape control mode, the tension leveling (shape correction) of the steel strip 41 can be performed so that an elongation percentage that is arbitrarily predetermined matches the elongation percentage set value ε. The above-described tension leveling method is an example of a leveler processing method. The same effect can be obtained by using another equipment, for example, a roller leveling method, which is another example of the leveler processing method, instead of the tension leveling equipment 81.

In the temper rolling equipment 42 and the tension leveling equipment 81 (hereinafter, may be abbreviated as “each equipment 42, 81”) according to the above-described embodiments, the α ′ amount is limited with respect to the material control material. Control is performed. As described above, since the α ′ amount has a strong correlation with the mechanical properties of the steel strip 41, the target α ′ amount set in advance in the α ′ amount setting device 64 includes an α value corresponding to a desired mechanical property. The steel strip 41 having the desired mechanical properties can be obtained with high reliability by setting the 'amount and controlling the α' amount, that is, the material control. As a result, the occurrence of defective test values can be reduced, and the yield can be improved.

Further, since the re-heat treatment for relieving the defective portion of the test value can be reduced, the unnecessary heat treatment can be avoided, and the heat treatment equipment can be effectively used. As a result, running costs can be reduced. Further, since the control of the α ′ amount is performed by controlling the elongation percentage of the steel strip which directly affects the change of the α ′ amount, the measured α ′ amount and the target α ′ amount can be quickly and accurately determined. Can be controlled to match.

In each of the facilities 42 and 81, the steel strip 41 is plastically deformed with respect to the shape control material such that the measured elongation percentage matches a predetermined elongation percentage set value ε. You. The flatness of the steel strip 41 can be corrected by giving an elongation percentage according to the material. Since the elongation rate setting value ε output from the elongation rate setting device 67 can be arbitrarily set according to the product specification required, the shape of the steel strip 41 is controlled so as to produce the arbitrarily set elongation rate. be able to. Thereby, the flatness of the steel strip 41 can be corrected with high precision.

Next, the steel strip 4 by the α 'amount measuring sensor 61 is used.
The method for measuring the α 'amount of No. 1 will be described. In the temper rolling facility 42 and the tension leveling facility 81 according to the above-described embodiment, a thickness measuring sensor (not shown) is provided in proximity to the α ′ amount measuring sensor 61. The sheet thickness sensor is, for example, an X-ray sheet thickness gauge, and includes an X-ray generator provided on one side in the thickness direction of the steel strip 41 and an X-ray measuring instrument (counter) provided on the other side in the thickness direction of the steel strip 41. ).
X-rays are emitted from the X-ray generator, and the emitted X-rays and steel strip 4
The attenuation rate is detected from the X-ray transmitted through 1 and incident on the X-ray measuring instrument, and the thickness can be determined based on a calibration curve indicating the relationship between the thickness and the attenuation rate determined in advance. In this way, the thickness can be measured in a non-contact manner.

Further, in order to accurately measure the α ′ amount, each of the above facilities 42 and 81 is provided with a steel plate 41 along a threading path.
A steel strip temperature measuring sensor (not shown) is provided near the thickness measuring sensor, and a detailed description thereof will be described later.

FIG. 5 is an enlarged front view showing the appearance of the α ′ amount measuring sensor 61, and FIG. 6 is a block diagram showing a schematic configuration for measuring the α ′ amount by the α ′ amount measuring sensor 61. The α ′ amount measuring sensor 61 includes a pair of wheels 121a, 1
The sensor body 122 has a lower end surface 122a provided at a distance ΔL from the surface 41a of the steel strip 41, and the sensor body 122 is supported by the sensor body 122.
Is selected to be 1 to 4 mm. If the distance ΔL is less than 1 mm, the lower end surface 122a of the sensor main body 122 comes into contact with foreign matter generated on the surface 41a of the steel strip 41, making measurement difficult. If the distance ΔL exceeds 4 mm, a normal measurement range is obtained. , And it becomes impossible to accurately measure the amount of α '. By selecting an interval of 1 to 4 mm in this way, it is possible to measure the α ′ amount with high accuracy.

The sensor body 122 includes a probe 123 made of a ferromagnetic material, an upper and lower two-stage excitation coil 124 mounted near both ends of the probe 123 in the axial direction, and a coaxial shaft inside the excitation coil 124. And a detection coil 125, which constitutes a differential transformer. The excitation coil 124 has a frequency of 5 kHz during measurement.
Excited by an alternating current of about 2 MHz, the detection coil 1
A constant electromotive force is generated in the 25 windings. When the measurement is not performed, the windings of the excitation coil 124 and the detection coil 125 are balanced so that the voltages are equal. However, during the measurement, the balance is lost, and the electromotive force having a different magnitude is generated in the winding of the detection coil 125. Is induced, and this voltage difference is governed by the absolute amount of the α ′ phase.

The α ′ amount measuring sensor 61 includes an exciting coil 1
A detection device 126 is provided for supplying an excitation current to the detection coil 24 and detecting a detection current induced by the detection coil 125. By detecting the detected current in a state where the distance ΔL between the sensor body 122 and the steel strip 41 is kept constant, it is possible to measure the magnetic characteristics, that is, the material of the steel strip 41 as α ′. The output from the α ′ amount measuring sensor 61 is given to an α ′ amount calculating device 62.

It is known that the measurement of the α ′ amount by the α ′ amount measurement sensor 61 causes an error due to influence factors such as the thickness, tension, and temperature of the steel strip 41. In the present embodiment, since the excitation frequency is selected from the above-mentioned 5 kHz to 2 MHz, the detected value is hardly affected by the thickness and temperature of the steel strip 41. Further, in order to accurately obtain the α ′ amount, the outputs of the sheet thickness measuring sensor and the steel strip temperature measuring sensor are supplied to the α ′ amount calculating device 62, and the tension of the steel strip 41 is applied to each of the facilities 42 and 81. An unillustrated tensiometer for detection is provided, and the output of the tensiometer is provided to the α 'amount calculating device 62.

The steel strip temperature measuring sensor is realized by a radiation thermometer. The infrared ray emitted from the steel strip 41 is converged and made incident on the sensor main body, and by detecting the infrared energy, the temperature of the steel strip 41 is detected. Can be measured in a non-contact manner. The tension meter is realized by, for example, a load cell provided with a strain gauge, and can detect, for example, a load applied to a deflector roll, and can derive a tension from the load.

In the α ′ amount calculating device 62, the thickness measured by the thickness measuring sensor, the α ′ measured by the α ′ measuring sensor 61, the steel strip temperature measured by the steel strip temperature measuring sensor, and Based on the tension measured by the tensiometer, the error of the α ′ measured by the α ′ measuring sensor 61 due to the influence factors of the thickness, tension, and temperature of the steel strip 41 is corrected, and the calculated value is measured. The value is output to the α 'amount comparator 63 as the α' amount. Thus, the α ′ amount of the steel strip 41 can be accurately measured. In each of the facilities 42 and 81, the α ′ amount measuring sensor 61 detects the α ′ amount of the tempered rolled steel strip 41 conveyed from the mill body 43 or after the leveler processing conveyed from the roll unit 82. Is continuously measured, so that the measured α '
By visually checking the display device for indicating the amount,
The α 'amount of 1 can be easily and accurately grasped over the entire length of the steel strip 41. Normally, the temper rolling and the leveler processing are the final steps, and the steel strip 41 after the temper rolling and the leveler processing is inspected to see if it can be shipped as a product. As described above, since the α ′ amount of the steel strip 41 has a strong correlation with the mechanical properties of the steel strip 41, the mechanical properties of the steel strip 41 corresponding to the displayed measured α ′ quantity are determined by the user. It is possible to prevent the test value defective portion from flowing out as a product by determining whether or not the test value defective portion exceeds the allowable range and eliminating the test value defective portion exceeding the allowable range. Further, a recording device for recording the displayed measured α ′ amount and the position information of the steel strip 41 may be provided. By giving the coil inspection form recorded by this recording device to the user, the quality assurance over the entire length of the steel strip 41 to be the shipped product can be reliably performed.

[0064]

As described above, according to the present invention, the α 'amount of the metastable austenitic stainless steel strip after the temper rolling can be accurately grasped over the entire length, and thus the leakage of the test value defective portion can be prevented. And the quality assurance over the entire length of the steel strip to be shipped can be ensured.

Further, since the α ′ amount of the steel strip is accurately controlled so as to coincide with the target α ′ amount, it is possible to reliably obtain the steel strip having the target mechanical properties.
As a result, it is possible to prevent the occurrence of a test value defective portion, so that the product yield can be greatly improved.
In addition, since re-heat treatment for relieving defective test values can be reduced, unnecessary heat treatment can be avoided, and heat treatment equipment can be effectively used. As a result, running costs can be reduced. Further, since the control of the α ′ amount is performed by controlling the elongation percentage of the steel strip which directly affects the change of the α ′ amount, the measured α ′ amount and the target α ′ amount can be quickly and accurately determined. Can be controlled to match.

According to the present invention, the elongation rate is controlled by controlling the tempering rolling force which directly affects the elongation rate. The control range can be greatly expanded.
In addition, since the maximum rolling force can be set smaller than the critical rolling force in the equipment specifications of the temper rolling mill, the failure of the temper rolling mill can be prevented and the service life of the temper rolling mill can be greatly extended. Can be done. In a steel strip to which a constant rolling force has been applied, increasing the tension applied to the steel strip increases the elongation. For example, even when a tempering rolling force exceeding the limit in the equipment specifications of the temper rolling mill is required, a predetermined elongation can be obtained by controlling the tension applied to the steel strip. Therefore, the control range of the α ′ amount can be greatly expanded.

Further, according to the present invention, since the α 'amount of the metastable austenitic stainless steel strip after the leveler processing can be accurately grasped over the entire length, it is possible to surely prevent the outflow of the defective portion of the test value. Thus, quality assurance over the entire length of the steel strip to be shipped can be reliably performed.

Further, since the α ′ amount of the steel strip is precisely controlled so as to coincide with the target α ′ amount, it is possible to reliably obtain the steel strip having the target mechanical properties.
As a result, it is possible to prevent the occurrence of a test value defective portion, so that the product yield can be greatly improved.

[Brief description of the drawings]

FIG. 1 shows a temper rolling plant 42 capable of suitably controlling the amount of work-induced martensite of a metastable austenitic stainless steel strip 41 according to an embodiment of the present invention.
FIG. 2 is a system diagram showing the configuration of FIG.

FIG. 2 is a flowchart for explaining a method for temper rolling a metastable austenitic stainless steel strip 41 according to an embodiment of the present invention.

FIG. 3 is a system diagram showing the configuration of a tension leveling facility 81 capable of suitably controlling the amount of work-induced martensite of a metastable austenitic stainless steel strip 41 according to another embodiment of the present invention. .

FIG. 4 is a flowchart illustrating a tension leveling method for a metastable austenitic stainless steel strip 41 according to another embodiment of the present invention.

FIG. 5 is an enlarged front view showing the appearance of the α ′ amount measurement sensor 61.

6 is a block diagram showing a schematic configuration diagram for measuring an α ′ amount by an α ′ amount measuring sensor 61. FIG.

FIG. 7 is a system diagram showing a configuration of a temper rolling plant as a typical prior art.

FIG. 8 is a system diagram showing a configuration of a tension leveling facility which is a typical prior art of a leveler processing facility.

[Explanation of symbols]

41 Metastable Austenitic Stainless Steel Strip 42 Temper Rolling Equipment 43 Mill Body 44 Payoff Reel 45 Tension Reel 46 Inlet Deflector Roll 47 Outlet Deflector Roll 48a, 48b Vertical Work Roll 49a, 49b Vertical Backup Roll 50 Rolling Down Cylinder 53 Payoff Reel Driving motor 55 Tension reel driving motor 61 α ′ amount measuring sensor 62 α ′ amount calculating device 63 α ′ amount comparator 64 α ′ amount setting device 66 Control target changeover switch 67 Elongation ratio setting device 68 Pressure reduction / tension changeover switch 69 Reduction force Adder 70 Rolling force setting device 71 Rolling force control device 72 Tension calculator 73 Tension setting device 75a, 75b Tension controller 76a, 76b Pulse generator with built-in high-speed counter 77 Elongation ratio calculator 78 Passing speed controller 7 9 Elongation Rate Comparator 81 Tension Leveling Equipment 82 Roll Unit 83 Payoff Reel 84 Tension Reel 88 Inlet Bridle Roll 91 Outlet Bridle Roll 96, 97 Power Distribution Device 98 Elongation Rate Control Differential Device 99 Bridle Main Drive Motor 100 Elongation Rate Control Motor 101 Speed control device 102 First pulse generator 103 High speed counter 104 Passing speed converter 111 Converter 112 Speed adder 113 Motor speed controller for elongation rate 114 Second pulse generator 115 High speed counter 116 Control speed converter 117 Elongation rate Arithmetic unit 122 Sensor main body 123 Probe 124 Excitation coil 125 Detection coil 126 Detection device

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Claims (3)

[Claims] In the method of temper rolling of a metastable austenitic stainless steel strip, at least the amount of work-induced martensite of the stainless steel strip after temper rolling is measured, and the measured value is a predetermined amount of work-induced martensite. A temper rolling method for a metastable austenitic stainless steel strip, comprising controlling an elongation percentage of the stainless steel strip so as to be a target value. 2. The control of the elongation percentage of the stainless steel strip is as follows:
When the tempering rolling force of the temper rolling mill is equal to or less than the predetermined maximum rolling force, the heat treatment is performed by controlling the tempering rolling force, and when the tempering rolling force of the temper rolling mill exceeds the predetermined maximum rolling force. The temper rolling method according to claim 1, wherein the temper rolling is performed by controlling the tension of the stainless steel strip while maintaining the temper reduction force at the maximum reduction force. 3. A leveler processing method for a metastable austenitic stainless steel strip, comprising: measuring at least the amount of work-induced martensite of the stainless steel strip after the leveler processing; A leveler processing method for a metastable austenitic stainless steel strip, comprising controlling an elongation percentage of the stainless steel strip so as to be a target value.