JPS5853340A - Plastic working method - Google Patents

Abstract

PURPOSE:To elevate the working efficiency, by measuring the magnetic permeability of a substance to be worked, and plastically working the substance to be worked at the point of time when said value has dropped by a drop ratio obtained in advance. CONSTITUTION:Before a substance to be worked 1 is worked, an experimental measurement is executed by use of a material whose quality is similar. That is to say, plural materials are heated up to a state showing each different magnetic permeability, each working is executed in its state, and a degree on whether said working is difficult or easy is measured. By obtaining magnetic permeability in an optimum working state in which working is executed most easily, a drop ratio of a value of magnetic permeability in the optimum working state is known. Subsequently, the substance to be worked 1 is electrically conducted from an electric power supply 8, is heated, and magnetic permeability of the substance to be worked 1 is measured by a magnetic sensor 10. When the value of magnetic permeability has passed the maximum and has become a value which has dropped by a ratio derived by the experiment, the electric condition is stopped, and drawing is executed by operating a drawing device 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for plastically working metal materials in warm or hot conditions.

It is well known that when a metal material undergoes a phase transformation, it exhibits a superplastic phenomenon and is capable of significantly large plastic deformation, and its industrial use as a new plastic working method is beginning.

On the other hand, the temperature of metal materials differs slightly due to fluctuations in the constituent elements that cause the above-mentioned phase transformation, and also varies depending on the heat treatment history and processing history, and furthermore, the temperature changes depending on the heating or cooling rate to reach that temperature. be done. Therefore, by measuring the temperature of the workpiece, it is impossible to detect that the workpiece has reached the optimum machining state, that is, a state in which significantly large plastic deformation is possible as described above, which inevitably involves an error. There is a problem in that it is difficult to accurately match the timing when the workpiece reaches the optimum processing state and the time when the plastic working means is applied to the workpiece, making it difficult to apply it on an industrial scale.

The present invention solves these technical difficulties by measuring the above-mentioned workpieces with extremely high accuracy, without being influenced by internal factors such as the chemical composition and material history of the workpiece, or external factors in measurement. The present invention aims to provide a plastic working method that can match the time when the optimum working state is reached and the time when the plastic working means is applied, and can greatly improve the processing efficiency. .

The drawings showing the embodiments of the present application will be described below.

In FIG. 1, which shows an example of a mode of plastic working, l is a workpiece, which is a steel material or various other magnetic metal materials.

It is fixed to a fixed object 3 by a two-piece chuck, and this chuck 2 is configured to fix one end of the workpiece 1 and to conduct electricity to the workpiece 1. The 4Fi chuck is configured to be able to pull the other end of the workpiece 1 and to energize the workpiece. A tension device is shown as an example of a 5-piece machining device, and its piston 6 is connected to a chuck 4, and when pressure oil is injected from a boat 7, the piston 6 moves in the direction of the arrow, moving the chuck 4 in the direction of the arrow. It has a long lifespan that can be used for a long time. Reference numeral 8 denotes a heating power source for directly applying electricity to the workpiece 1 via the chucks 2 and 4 to heat the workpiece 1. Reference numeral 9 denotes a power control circuit for controlling the power applied to the workpiece 1 from the power source 8. The magnetic permeability of the workpiece 1 is measured using ten magnetic sensors.

Next, an example of the plastic working method (tension working) of the workpiece 1 using the above-described structure will be explained.

(1) Before processing the workpiece 1, perform experimental measurements. First, a plurality of materials of the same type as the workpiece 1 are prepared. In this specification, the rate of decrease in magnetic permeability under the optimal processing state of the material is approximately equal to the maximum value of magnetic permeability shown in the process of melting the same type of material and applying temperature changes to the material. Refers to materials that are equal. Note that for many of the materials classified by JIS type symbols, the above ratio is equal to that of baldness in the classification.

The size of each of the above-mentioned materials may be small enough to be processed. Next, each material is heated and its magnetic permeability is measured during the heating process. When the magnetic permeability of each of the above-mentioned materials reaches the maximum value (up) as shown in FIG. 2, heating is terminated and processing is performed. For other materials (r5), the magnetic permeability exceeds the maximum value and reaches the maximum value μ.

When the value reaches 11, which is slightly lower than 11, the heating is terminated and the same processing is performed. Further, for other materials, heating is performed while measuring the magnetic permeability in the same manner, and when the magnetic permeability reaches pg, which is further decreased from the above-mentioned P1, heating is terminated and processing is performed. In this way, each of the above-mentioned plurality of materials has a different magnetic permeability 'y''p1/l1lS)Is,p
g --- The material is heated to a state where it shows, and in that state, each process is performed, and the difficulty level of those processes is measured. Then, obtain the magnetic permeability values when these materials are used (optimum processing conditions), and find the rate of decrease in the magnetic permeability values under the optimum processing conditions with respect to the above-mentioned maximum value. In the case of the above-mentioned experimental measurements, the measurement can be carried out using the apparatus shown in Figure 1, and the magnetic permeability and processing can be carried out using an apparatus of other configurations. You may also measure the difficulty level.

(2) Next, the workpiece 1 is processed. Process it (4
) Do this in the following order: First, electricity is applied directly to the workpiece 1 from the power source 8 via the chucks 2 and 4 to heat the workpiece 1. In this heating case, the magnetic sensor 10
The magnetic permeability of the workpiece 1 is measured at any time or continuously. If the value of magnetic permeability measured during the heating process passes the maximum and becomes a value that is reduced by the proportion determined in the experiment above from the value at the maximum, then Turn off the electricity and stop heating. Then, the tensioning device 5 is operated to tension the workpiece 1. In addition, when there are many workpieces 1 and plastic working is performed on another workpiece (workpiece formed of the same type of material) that is different from the workpiece 1 that has been processed above, the above method may be applied. The magnetic permeability is measured in the same manner as in the above case, and processing is performed when the magnetic permeability exceeds the maximum value and reaches a value reduced by the proportion determined in the experiment.

When processing as described above, processing is performed for each workpiece 1 when its magnetic permeability passes the maximum value and reaches a value reduced by the proportion determined in the experiment. , any workpiece 1 can be processed when it reaches the optimum processing state,
Therefore, any workpiece can be processed in an extremely easy condition and with good workability.

Next, various aspects of the above-mentioned processing are as follows.

(a) The process of temperature change in which the above operations are applied to the workpiece includes, in addition to the temperature raising process due to heating as described above, over-wetting due to cooling of the heated workpiece.

(b) When heating the workpiece, well-known methods such as furnace heating (atmosphere heating, induction heating, etc.) can be applied in addition to the above-mentioned direct current heating.

As described above, in the present invention, when the workpiece 1 is plastically worked, the magnetic permeability of the workpiece 1 is set to a value corresponding to the magnetic permeability value in the optimum processing state determined in advance by experiment. Since plastic working is performed at the point when the workpiece 1 has become extremely (7) K plastic working, it is possible to perform plastic working in a state where it is easily subjected to plastic working, which has a great effect on extremely improving processing efficiency. There is.

Moreover, the reason why the above corresponding values were obtained is that the rate of decrease in the value of magnetic permeability under the optimum processing condition with respect to the maximum value of magnetic permeability was determined in advance through experiments, and when plastically working the actual workpiece, it was necessary to , the measured value of the magnetic permeability of the workpiece passes the maximum and becomes a value that has decreased by the above percentage. (1) When processing multiple workpieces individually, their Even if there is a change in the shape or bulk of the workpieces, or the conditions that cause temperature changes (temperature increase rate, etc.) are different for each workpiece, each of the workpieces (2) When processing multiple workpieces, even if there are variations in the materials of the workpieces, the variation can be accurately determined. It is possible to accurately determine that the optimal machining state has been reached for each workpiece (8), and in either case, machining in the high machining efficiency state described above can be performed appropriately for each workpiece. There are great effects that can be achieved.

[Brief explanation of the drawing]

The drawings show an embodiment of the present application, and FIG. 1 is a conceptual diagram of a processing device, and FIG. 2 is a diagram showing an example of changes in magnetic permeability during the process of heating a workpiece. l... Workpiece, 10... Magnetic sensor, 5...
Tension device. Figure 1 Figure 2 Temperature 206-

Claims (1)

[Claims] For materials of the same type as the workpiece, the maximum value of magnetic permeability shown in the process of applying humidity changes to the material was experimentally measured, and the value of magnetic permeability of the above material under its optimum processing condition was also experimentally measured. Measure the magnetic permeability value in advance to obtain the ratio of decrease in the magnetic permeability value under the optimal processing condition to the maximum value of the magnetic permeability, and then apply a temperature change to the workpiece to perform warm or hot plastic working. In order to do this, the magnetic permeability of the workpiece that has been subjected to the above temperature change is measured, and at the point when the measured value passes the maximum and reaches a value that has decreased by the predetermined rate of decrease, the workpiece is A plastic working method characterized by plastic working.