JPH07179952A - Method for controlling heat treatment of material, device for controlling heat treatment and instrument for measuring heat treatment history - Google Patents

Abstract

PURPOSE:To accurately control mechanical property of an objective material through an accurate temper effect by measuring the temp. of the material at each interval of a prescribed time to calculate an integration temper parameter, comparing the result with the set value and controlling a heating temp. and a heating time. CONSTITUTION:The temp. of the steel material 2 heated in a heat treatment furnace 1 is observed by a contact thermometer 3. Measured values by the thermometer 3 and a time measuring device 7a are outputted to an operating part 8 at each interval of a prescribed time to calculate the integration parameter P. The result is displayed on a CRT 9a, printed with a printing device 9b and recorded on a recording device 9c. The measured integration temper parameter is successively compared with the preset temper parameter to control the heating temp. and the heating time in a heating means for heat treatment. When a correlation between the integration temper parameter and the mechanical property of the material is found beforehand, in the actual operation, the mechanical property of the material can accurately be controlled in response to the temp. changed every moment and the operations of slow heating and slow cooling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention converts the heat history of a product in the heat treatment manufacturing of a steel material or the like in the aging treatment into an integrated temper parameter P, and manages the heat treatment operation by using this P value. The present invention relates to a heat treatment control method, a heat treatment control device, and a heat treatment history measuring device that control mechanical properties of materials with high precision.

[0002]

As is well known, in the tempering process of steel, a tempering effect mainly determined by heat treatment time and heating temperature is obtained. As a method of evaluating this tempering effect,
A method is generally known in which the P value (temper parameter; according to the Larson-Miller equation) indicating the compatibility between the heat treatment time and the temperature is used and the value is evaluated. The above-mentioned Larson-Miller equation is expressed by the following equation: P = (273 + T) × (logt + A) (1) T: temperature (° C.) t: time (hr) A: constant This P value And the correlation between the mechanical properties of the steel after heat treatment,
For example, it is organized as laboratory data as shown in FIG.

Conventionally, from such a viewpoint, even in actual operation, a preset P value is set in advance, and a target value of heating temperature and heating time is determined from this P value, and the heat treatment furnace is adjusted so as to match the target value during operation. The desired heating temperature and heating time are controlled to obtain desired mechanical properties. This will be specifically described with reference to FIG. 6. A target temper parameter is set in advance in accordance with a desired mechanical property, and the heat treatment temperature and time are set as target values from the temper parameter, and the controller 24 is set. Enter it. After the treatment is started, the atmosphere temperature of the heat treatment furnace 21 is measured by the atmosphere thermometer 20, and the contact temperature of the target material 23 is measured by the contact thermometer 22. Since the above contact temperature gradually approaches the ambient temperature as the temperature rises as shown in FIG. 4, the controller 25 controls the controller 25 so as to match the target value after the contact temperature reaches a steady state. To adjust the ambient temperature.

[0004]

On the other hand, in the actual production of large cast and forged steel products and the like, the heat history is such that the temperature changes moment by moment, and gradual heating and gradual cooling are often unavoidable. The tempering effect is progressing even during these temperature increases and coolings, and it is difficult to give an accurate tempering effect to the target material simply by managing it according to a constant target value as in the conventional case. Therefore, it is difficult to accurately control the mechanical properties of the material after the heat treatment, and there is a problem that the quality varies depending on the product. The present invention has been made in view of the above circumstances, and provides a heat treatment control method for a material, a heat treatment control apparatus, and a heat treatment history measurement apparatus capable of accurately controlling the mechanical properties of a target material by giving an accurate temper effect. The purpose is to do.

[0005]

In order to solve the above problems, the method of controlling heat treatment of a material of the present invention is to measure the temperature of the material to be heat treated at every predetermined time during heat treatment, and from this temperature data and time data, The integrated tempering parameter is calculated, the calculated integrated tempering parameter and the preset tempering parameter are sequentially compared, and the heating temperature and the heating time of the heat treatment heating means are controlled based on the comparison result.

Further, the heat treatment control apparatus of the second invention is such that the temperature measuring means for measuring the temperature of the material to be heat treated, the time measuring means for measuring the time during the heat treatment, the temperature measurement data and the time from the temperature measuring means. And a calculation unit that receives the time data from the measurement means and calculates the integrated temper parameter,
Further, it is characterized by further comprising a comparing section for comparing the data calculated by the calculating section with a preset temper parameter, and a heating control means for controlling the heat treatment heating means based on the result of the comparing section.

Further, the third invention comprises a temperature measuring means for measuring the temperature of the material to be heat treated, a time measuring means for measuring the time during the heat treatment, temperature measurement data from the temperature measuring means and a time measuring means. The present invention is characterized by having a calculation unit that receives time data and calculates an integrated temper parameter, and a data processing unit.

The material to be heat treated is mainly cast and forged steel products, but the present invention is not limited to this, and other materials (for example, non-ferrous materials) whose heat treatment effect is evaluated by temper parameters may be used. Good. For the above temperature measurement, it is desirable to use a contact thermometer or the like that directly measures the temperature of the target material, and it is also possible to use an atmosphere thermometer together. In addition to the method of measuring the elapsed time, the time may be measured by a timer indicating a time interval.
A storage unit for accumulating these data may be added to the arithmetic unit for calculating the integrated parameter based on the data obtained from these measuring means, if necessary. In the data processing unit of the heat treatment history measuring device, data processing of the calculation result in the calculation unit, processing temperature, and time is performed. This data processing unit can be configured, for example, as a display device, a printing device, a data storage device, or a combination thereof.

[0009]

In other words, according to the present invention, an accurate P value along the temperature rising curve can be obtained corresponding to the temperature change that changes momentarily during heat treatment, gradual heating, and gradual cooling. In the measuring device of the present invention,
Since the P value is processed by the data processing unit, the accurate P value can be accurately grasped and can be immediately output if desired. By controlling the heat treatment temperature and time in the heat treatment process using this P value, the tempering effect can be accurately given to the target material, and the mechanical properties can be accurately controlled. Further, according to the heat treatment control method and the heat treatment control device of the present invention, the heat treatment temperature and time are controlled while comparing with the preset P value, so that the tempering effect can be controlled more accurately and quickly. .

The calculation of the integrated temper parameter is
For example, the following method is used. First, as shown in FIG.
The lower limit of the temperature (contact temperature) to be calculated within a predetermined time range (to to te) is set (T1). Then, the temperature is measured at a predetermined time interval (Δt) in a range equal to or higher than this temperature. The temper parameter P1 at the time of the first measurement is P1 = (273 + T1) * (lo
gΔt + A). Then, at the next calculation, the temperature becomes T2. When the above-mentioned temper parameter P1 is converted into this temperature and the calculated minute time is Δt1, the following formula is obtained. (273 + T1) * (log Δt + A) = (273 + T
2) * (log Δt1 + A) Then, the integrated parameter P within the time (2 × Δt) related to the above two calculations is P = (273 + T2) * (l
og (Δt + Δt1) + A). Therefore, by repeating this, the integrated parameter P from the beginning to the time of calculating n times is expressed by the following equation. P = (273 + Tn) * (log ΣΔtn + A) (2) By calculating the integrated parameter by the above formula (2) according to the above method, the integrated parameter P up to n times of measurement is obtained.
The value is obtained accurately.

[0011]

【Example】

(Embodiment 1) An embodiment of the heat treatment measuring apparatus of the present invention will be described below with reference to FIG. A contact thermometer 3 as a temperature measuring means is connected to a steel material (material to be heat treated) 2 arranged in a heat treatment furnace 1, and one end of an atmosphere thermometer 4 is arranged in the furnace 1. Steel material 2 in 1 of heat treatment furnace
The heating means 5 is arranged in correspondence with the heating means 5. The heating means 5 is connected to the controller 6 for adjusting the heating means 5, and the controller 6 is connected to the controller 7 including the time measuring device 7a. .
Further, the output sides of the contact thermometer 3 and the time measuring device 7a are connected to a calculation unit 8, and the output of the calculation unit 8 is connected to a CRT 9a, a printing device 9b, and a recording device 9c which constitute a data processing unit. ing.

The operation of the above measuring apparatus will be described below.
First, the controller 7 defines a procedure for controlling the adjuster 6. According to this procedure, the steel material 2 is heated in the heat treatment furnace 1 and its temperature is observed by the contact thermometer 3. The outputs of the thermometer 3 and the time measuring device 7a are output to the calculation unit 8 every one minute, and the integrated parameter P is calculated by the equation (2) described above. The result is sent to the CRT 9a, the printing device 9b, and the recording device 9c. The integrated tempering parameter is displayed on the CRT 9a, printed by the printing device 9, and recorded and saved in the recording device 9c. In the data processing unit, it is not necessary to operate these devices at the same time, and they can be operated independently or at different times. Also,
The saved contents of the recording device 9c can be saved again in a magnetic card, an IC card, or the like.

The integrated temper parameter measured as described above can be used to derive a correlation between the temper parameter and the mechanical properties of the material. Therefore, if the above correlation is obtained with this measuring device, in actual operation, by controlling the heat treatment temperature and time based on the information obtained by the measurement, it is possible to control the temperature that changes momentarily, gradual heating, and gradual cooling. Correspondingly, the mechanical properties of the material can be precisely controlled. If a magnetic card or the like used as desired in the recording device 9c is used as an input device data card or the like in actual operation, the input work can be performed easily and accurately.

(Embodiment 2) Next, an embodiment of the heat treatment control method and apparatus of the present invention will be described with reference to FIGS. In this embodiment, the same structures as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. In this device, the output side of the calculation unit 8 is connected to the comparison unit 10, and the P value input device 11 is further connected to the input side of the comparison unit 10. The output side of the comparison section 10 is connected to a control section 12 having a timer 12a built therein, and the controller 6 is connected to the output side of the control section 12, and the control section 12 and the controller 6 are connected to each other.
The heating control means is constituted by. The timer 12a described above is connected to the arithmetic unit 8 described above.

Next, the operation of the heat treatment control device will be described with reference to the flowchart of FIG. First, the P value selected so that desired mechanical properties are obtained is input to the P value input device (step 1). In addition to manual input, this input can also be performed by a method using a magnetic card, floppy disk or the like in which necessary data is stored. In addition to the P value, heat treatment temperature and time data are input to the P value input device 11. These data are sent to the comparison unit 10 as needed, and then the heat treatment temperature and time data are input to the control unit 12 as operation data (step 2). The data input to the P value input device 11 can be used as this data.

The controller 12 controls the controller 6 based on the input data to heat the inside of the heat treatment furnace 1 to a desired temperature by the heating means 5 (step 3). The steel material 2 is gradually heated, and the temperature is observed by the contact thermometer 3 (step 4). The outputs of the thermometer 3 and the time measuring device 7a are the same as those in the first embodiment.
Is output to the calculation unit 8 in the same manner as above, and the integrated temper parameter P is calculated (step 5). This P value is calculated by the calculation unit 8
From the P-value input device 11 to the corresponding data extracted from the P-value input device 11 (step 6). In the comparison unit 10, based on this comparison result,
If the measured temper parameter is smaller than the set value, the controller 12 is instructed to raise the heating temperature or extend the heating time. The control unit 12 corrects the control contents according to this instruction (step 7). By repeating the above operation, the heat treatment conditions are managed and the heat treatment is completed.
The heat-treated steel material has properties very close to desired mechanical properties due to proper control of temper parameters.

[0017]

As described above, according to the present invention, since an accurate integrated tempering parameter can be obtained during heat treatment, an accurate tempering effect can be obtained by using this and the mechanical properties of the material to be heat treated can be obtained. The properties can be controlled precisely.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram of a second embodiment.

FIG. 3 is a flowchart showing a control procedure of the second embodiment.

FIG. 4 is a graph showing the contents of temperature measurement according to the present invention.

FIG. 5 is a graph showing an example of the correlation between temper parameters and mechanical properties.

FIG. 6 is a block diagram of an apparatus used for conventional heat treatment control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat treatment furnace 2 Steel material 3 Contact thermometer 5 Heating means 6 Regulator 7 Controller 7a Time measuring device 8 Calculation part 9a Display 9b Printing device 9c Recording device 10 Comparison part 12 Control part 12a Timer

Claims (3)

[Claims] 1. A temperature of a material to be heat treated is measured every predetermined time during heat treatment, an integrated temper parameter is calculated from the temperature data and time data, and a calculated integrated temper parameter and a preset temper parameter are set. Are sequentially compared, and the heating temperature and heating time of the heat treatment heating means are controlled based on the comparison result. 2. A temperature measuring means for measuring a temperature of a material to be heat treated, a time measuring means for measuring a time during the heat treatment, a temperature measurement data from the temperature measuring means and a time data from the time measuring means, and integrated. And a comparison unit that has a calculation unit that calculates a temper parameter, and that compares the data calculated by this calculation unit with a preset temper parameter, and controls the heat treatment heating unit based on the result of the comparison unit. A heat treatment control device having a heating control means 3. A temperature measuring means for measuring a temperature of a material to be heat treated, a time measuring means for measuring a time during the heat treatment,
A heat treatment history measuring device comprising: a calculation unit that receives temperature measurement data from the temperature measurement unit and time data from the time measurement unit to calculate an integrated temper parameter; and a data processing unit.