JPS5825223B2 - Measuring method of mechanical peeling characteristics of wire rod scale by Acoustic compression method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for easily measuring the mechanical peeling characteristics of a rolled wire rod under conditions similar to those of an actual mechanical descaler.

After removing scale from the well-known rolled wire rod, it is subjected to J wire drawing and rolling to obtain secondary products.

Removal of this residual scale is a very important process, and so far, pickling descaling method and mechanical descaling method (mechanical descaling method) are known.

However, recently, with the rise in waste liquid treatment costs.

The pickling descaling method is being replaced by the mechanical descaling method.

However, the wire scale that is suitable for the pickling descaling method is not directly suitable for the mechanical descaling method, and these descaling methods have contradictory characteristics.

That is, those with a thin scale generation layer are suitable for the pickling descaling method, and those with a thick scale generation layer are suitable for the mechanical descaling method.

Therefore, wire rods to which the mechanical descaling method is applied must be evaluated using the appropriate test method.

By the way, a normal mechanical descaler first applies 7 to 9% elongation with a bending roll and removes the scale, and then removes the remaining scale with a wire brush, shot blast, etc. (This process is a continuous process. are doing.

) However, a mechanical descaler is not only expensive, but also requires a supply stand, wire drawing machine, etc., so a large amount of test material is required, resulting in a large-scale test.

For this reason, conventionally, the following method has been adopted to measure the mechanical peeling characteristics (hereinafter simply referred to as mechanical peeling characteristics) of wire scale.

1. One is to cut the material to the same length as for the tensile test, give it the same elongation as the bending roller of a mechanical descaler in a tensile tester, peel off the scale, and measure the mechanical descaling properties of the wire from the amount of weight loss caused by this. This is the way to find out.

In this method, measurement is performed through the steps of cutting out a sample, measuring its weight, applying tensile strain using a tensile testing machine, measuring its weight, and calculating the weight loss rate, which is time consuming and complicated.

In particular, reading errors during weight measurement and errors due to chuck impressions during applying tensile strain were a problem, and great care was required to apply a specified tensile strain.

Furthermore, actual mechanical descalers use bending rollers to apply elongation, but this method uses a tensile tester to apply vertical elongation, so there is a slight difference from the actual machine. Ta.

Another method is to bend the wire along a roll with the same curvature as the bending roller of a mechanical descaler, brush the tensile side with a nylon toothbrush, and observe with the naked eye or a microscope to determine the degree of scale remaining. There is.

However, although this method measures in a state similar to that of a mechanical descaler, the residual scale is determined using arbitrary scores and is carried out by visual observation, which results in variations in the measured values depending on the measurer, making it difficult to objectively measure the residual scale. There is a drawback that reliable measurement values cannot be obtained.

In view of the above-mentioned circumstances, those skilled in the art have longed for a method that can easily and accurately measure the mechanical delamination characteristics of a rolled wire rod under conditions similar to those of an actual mechanical descaling method.

In view of these circumstances, it is an object of the present invention to propose a method that solves the drawbacks of the conventional methods and can measure the mechanical peeling characteristics of rolled wire rods simply and accurately.

In other words, the feature of the present invention is that the acoustic emission device detects and records the sound generated by scale exfoliation caused by bending a wire rod along a roll with the same curvature as the bending roller of a commonly used mechanical descaler. The present invention provides a method for measuring the mechanical peeling characteristics of a wire rod scale by an acoustic emission method, which is characterized in that the mechanical peeling characteristics of the wire rod are measured by the waveform and/or the cumulative count number.

The present invention will be explained in more detail below based on an embodiment shown in the drawings.

Fig. 1 is a plan view of the main parts, Fig. 2 is a view from the A-person arrow in Fig. 1, Fig. 3 is an explanatory diagram showing the whole, Fig. 4 is a chart showing measured values in waveforms, and Fig. 5 is a chart showing the measured values of FIG. 4 in terms of cumulative counts.

A roller 2 having the same curvature as a bending roller used in a mechanical descaler is fixed on a base 1.

A cover plate 3 that is in close contact with the roller 2 is attached on the base 1.

An acoustic emission sensor 4 is brought into contact with the roll 3 via a contact medium such as grease.

At this time, the magnetic sensor may be fixed.

A test material 5 under the same conditions as the rolled wire rod is set between the cover plate 3 and the roll 2.

While the acoustic emission device 6 and recorder (for example, pen recorder γ) are turned on,
Gently bend it along the diameter of roll 2.

This bending strain causes the scale of the wire to peel off, and the acoustic emission sensor 4
Detect and record.

FIG. 3 is a measurement block diagram.

The sensor 4, which is in contact with the roll 2, contacts the acoustic emission device 6.

The output of 6 is led to pen recorder 1.

The signal detected by the sensor 4 is processed by the acoustic emission device 6 and then recorded in the pen recorder 7.

Part of the chart obtained in this way is shown in Figures 4 and 5.
As shown in the figure.

FIG. 4 shows the main amplifier output of the acoustic emission device 6, and FIG. 5 shows the cumulative count of acoustic emissions, and these are shown in correspondence.

The diameter of the target material for the measured values shown in these charts is 5,
5 mu/! ! This shows the scale peeling rate when the tensile strain is 4%.

A in Figures 4 and 5 has a scale peeling rate of 95% (A with a scale amount of 0.67 wt% is 89% (a scale amount of 0.3
9wt%), 72chi (scale amount 0.25wt%)
Here is an example.

As is clear from this 1-yard chart, the better the scale peeling rate, the greater the acoustic emission, and this fact shows that it can be used to evaluate the mechanical death characteristics of wire rods.

Therefore, by preparing a material whose mechanical death characteristics are known in advance, actually determining the mechanical death characteristics of the material to be measured using the acoustic emission method, and comparing this with a sample, the mechanical death characteristics of the material can be measured.

For example, the sample A in FIG. 4 is measured, and the gain of the acoustic emission measuring device is adjusted so that the acoustic emission signal (waveform; cumulative count number) at that time matches the sample A in FIGS. 4 and 5.

By measuring other samples in this way and comparing them with the waveforms and cumulative counts of A, the mechanical death characteristics of the material can be determined.

By using the method of the present invention to determine the acoustic emission characteristics of end materials applied to various mechanical descalers, and using the sample as a standard material, objectively reliable measurement data can be obtained.

Since the present invention is a measuring method as described above, the following remarkable effects can be obtained.

That is, in the method of the present invention, the mechanical peeling characteristics of the scale are directly recorded on the recording paper in the form of a waveform and/or cumulative count number, so that extremely reliable measurement data can be obtained.

Furthermore, since the method of the present invention applies bending strain using the same bending roller as in the actual machine (mechanical descaler) for measurement, it can sufficiently correspond to the scale removal characteristics of the actual machine.

Furthermore, these can be easily measured.

These effects are effects that could not be obtained by the conventional methods described above, and by adopting them for industrial production, they become even more valuable effects and can fully meet the needs of those skilled in the art.

In addition, in order to obtain the mecha-death characteristic value of a material using the conventional gravimetric measurement method, many measurements and calculations are repeated.
There is a high probability of making an error in the process.

However, in the method of the present invention, since the measured values are recorded as they are on the chart, there is less room for error than in the conventional method, and the accuracy is comparable to or higher than that in the conventional method.

[Brief explanation of the drawing]

Each of the drawings shows an embodiment of the method of the present invention.
Figure 1 is a plan view of the main parts, Figure 2 is a view taken along the line A-A in Figure 1, and Figure 3 is an explanatory diagram (block diagram) showing the whole.
, Figure 4 is a chart showing measured values in waveforms, and Figure 5 is a chart showing measured values in waveforms.
It is a chart which shows the measured value of a figure by cumulative count number. 1... Base, 2... Bending roller, 3... Cover plate, 4... Sensor (for acoustic emission), 5...・
Test material, 6...Acoustic emission device, 7...Pen recorder.

Claims (1)

[Claims] 1. Bending the wire along a roll with the same curvature as the bending roller of a commonly used mechanical descaler,
The acoustic emission method detects and records the sound generated by scale peeling due to bending using an acoustic emission device, and measures the mechanical peeling characteristics of the wire based on its waveform and/or cumulative count. Measuring method for mechanical release properties;