JPS60205355A - Flaw detecting method of wire rod - Google Patents

Abstract

PURPOSE:To perform ultrasonic flaw detection with high precision by providing a guide member which has a gap nearly equal to the diameter of a wire rod at the exit side of a die for wire drawing to the exit side of the die. CONSTITUTION:A water dipping tank 7 is provided at the downstream side of the die 5 and guide bushes 8 and 9 are fitted to the tank 7 concentrically with a communication hole, and those assist in prevention against oscillations of a product wire 3a during its transportation. The cylindrical contactor holder 11 of the ultrasonic flaw detector 10 is provided between the bushes 8 and 9 and three probes 12, (12a, 12b, and 12c) are arranged in the holder 11 around the axial center of the product wire 3a at equal intervals. Then, the probe 12a is installed for vertical flaw detection and the probes 12b and 12c are installed for surface flaw detection to perform flaw detection over all sections of the product wire 3a. Further, a guide die 6 is provided at the downstream side of the tank 7 and has a drawing hole with nearly the same diameter as the diameter of the product wire 3a; and the product wire 3a is held tightly without drawing work to prevent oscillations during its movement. Therefore, the ultrasonic flaw detection is performed precisely.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a wire rod flaw detection method, and proposes a wire rod flaw detection method that can accurately detect flaws existing on the surface and inside of a wire rod having a circular cross section, for example. It is.

[Prior art]

BACKGROUND ART Ultrasonic flaw detection is often used as a flaw detection method for wire rods having a circular cross section, for example, for detecting flaws existing in the surface layer and inside of the wire rod.

In this type of ultrasonic flaw detection method, in order to perform accurate flaw detection, large vibrations and
Specifically, it is important to prevent distance fluctuations between the wire rods from occurring due to vibrations during transport.

Tokuko Sho 5B-4 is a method that takes into consideration such vibration prevention.
There is a proposal in No. 9822.

That is, as shown in FIG. 1, the wire material 30 wound around the coil material drum 40 after rolling is fed out from the coil material drum 40 and subjected to a wire drawing process using wire drawing dies 15 and 16 to form an intermediate wire 3.
0a, the product wire 30b is wound up on the winding drum 20. A water immersion tank 70 is provided between the dies 15 and 16, and a probe holder 110 of an ultrasonic flaw detector +00 is rotatably placed in the tank 70 around the midline 30a between the dies 15 and 16. It is a provision. Inside the holder 110, two probes 120, 120 are arranged at different positions by 90''.
Flaw inspection is performed by projecting the beam onto the beam a and detecting its reflected echo. During this time, the intermediate line 30a is under tension 31. due to drawing as shown in FIG. It is assumed that vibration does not occur because S2 and the dies 15 and 16 are firmly held in a straight state.

However, according to research conducted by the inventor of the present application, it has been confirmed that when the above method is used, vibration occurs in the intermediate line 30a, making it impossible to perform accurate flaw detection.

This seems to be due to the following reasons. That is, when drawing is performed using two wire drawing dies 15 and 16, each die 15
．． Since the dimensions before and after processing with 16 are naturally different,
30, the speed of the intermediate line 30a is different, and both dice 15.
Vibration occurs in the middle 1j130a between 10 and 10 due to the difference in wire drawing speed at both ends.

〔the purpose〕

The present invention has been made in view of the above circumstances, and by providing a guide part (a) having a gap approximately equal to the diameter of the exit side of the wire rod on the exit side of the wire drawing die, the present invention can be positioned between the die guide members. The purpose of the present invention is to provide a wire rod flaw detection method that can prevent vibration of the wire rod by applying tension to the wire rod to make it straight and allow smooth transfer, and that can perform flaw detection with high accuracy. do.

(Structure of the Invention) The wire rod flaw detection method according to the present invention includes a wire drawing die and a guide member having a gap approximately equal to the exit side diameter of the wire rod on the exit side of the wire drawing die, and an intermediate portion between the two. It is characterized by the fact that flaw detection is carried out using flaw detection equipment installed at

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing embodiments thereof. FIG. 3 is a side sectional view showing the implementation state of the wire rod flaw detection method according to the present invention, and FIG. 4 is a schematic diagram showing the arrangement of probes. Surface shot 1 After surface treatment and pretreatment such as cleaning, the wire material 3 is passed through a drying oven 1.

A winding drum 2 is installed at a predetermined position on the exit side of the drying oven I.The winding drum 2 is for winding up the product wire 3a after wire drawing, so that the wire material 3 is as shown in the figure. It will be transported in the direction indicated by the white arrow. A guide roll 4 is installed near the exit side of the drying oven 1 to smoothly guide the transfer of the wire material 3. A wire drawing die 5 is installed downstream of the guide roll 4.
is provided. The die 5 reduces the area of the wire material 3 from 10 to
The diameter is reduced by 35% to form product line 3a. A water immersion tank 7 is provided downstream of the dice 5. Water immersion tank 7
A through hole is formed in each of the second and downstream walls, and the product wire 3n is passed through the through hole and transferred to the downstream side.

A gasket (not shown) is attached to the through hole of the tank 7 to prevent the water in the tank 7 from flowing out. A long cylindrical guide bush 8 is attached to the inner surface of the upstream wall of the tank 7 concentrically with the conduction hole, and a short cylindrical guide bush 9 is similarly attached to the inner surface of the downstream wall. , these help to prevent vibrations during transport of the product line 3a. A cylindrical probe holder 11 of the ultrasonic flaw detection device 10 is rotatably supported between both guide bushes 8.9 of the water immersion tank 7 so as to surround the product 1m13a, and is driven by a drive (not shown). It is rotated by the machine. Holder 11
As shown in Fig. 4, there is a 311&I probe 12a inside.
12b and 12c are equally spaced around the axis of the product line 3a.

The probe 12a is designed so that the center line of its incident wave faces the center of the product line 3a in order to perform vertical flaw detection.

On the other hand, the probes 12b and 12c are designed so that the center line of the incident wave is directed away from the center of the product line 3a and toward the surface in order to perform surface wave flaw detection. Such a probe 12
Product line 3 due to the arrangement of a, 12b, 12c
Flaw inspection can be performed on the entire cross section of a. Note that, instead of adopting such an arrangement, an oblique flaw detection method may be used. The flaw detection results of the ultrasonic flaw detection device 10 are sent to the marking device 13
is input to the paper detection section by the probe 12a and the probe 1
Color-coded markings are applied to the paper detection portions 2b and 12c, respectively.

Now, on the downstream side of the tank 7, a guide die 6 that characterizes the present invention is provided. Guide die 6 is product IJ13a
The product wire 3a is not drawn but is firmly held with a predetermined holding force to prevent vibration during movement.

When such a guide die 6 is used together with the wire drawing die 5, as shown in FIG. As described above, the tension S in the direction shown by the solid line arrow is applied due to drawing. This tension S makes the product wire 3a straight, and since both ends are firmly supported by the wire drawing die 5 and the guiding die 6, no vibration occurs. Since wire processing is not performed, vibrations due to differences in wire drawing speeds do not occur as in conventional methods, and therefore highly accurate ultrasonic flaw detection can be performed. Note that instead of the guide die 6, a guide member that does not perform wire drawing using a pinch roll or the like and has a gap approximately the same as the diameter of the product wire 3a may be used.

In addition, although the above-mentioned Example described the case where this invention was applicable to ultrasonic flaw detection, it goes without saying that it can also be applied to other non-destructive testing methods such as eddy current flaw detection.

〔effect〕

Next, the effects of the present invention will be explained based on examples. FIG. 6 is a graph showing the results of detecting the flaw depth by the method of the present invention, where the horizontal axis represents the flaw depth and the vertical axis represents the echo height.

However, the flaw detection frequency is ]OMIIz, and is based on the surface wave flaw detection method. As is clear from the graph, there is a linear correspondence between the flaw depth and the echo height, and the present invention allows highly accurate flaw detection.

As detailed above, the wire rod flaw detection method according to the present invention applies tension to the wire rod by providing a guide member having a gap approximately equal to the exit side diameter of the wire rod on the exit side of the wire drawing die, and straightens the wire rod. The present invention has excellent effects, such as being able to be used in inspections that require precision such as ultrasonic flaw detection, since it can be transferred without causing any vibration while maintaining the same state.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing the implementation state of the conventional method, Fig. 2 is a schematic diagram showing the product line, Fig. 3 is a side sectional view showing the implementation state of the method of the present invention, and Fig. 4 is a diagram of the probe. FIG. 5 is a schematic diagram showing the product line, and FIG. 6 is a graph for explaining the present invention in detail. 3... Raw wire material 3a... Product wire 5... Wire drawing die 6... Guide die IO... Ultrasonic flaw detection device
+2a, 12b. +2c...Probe patent Applicant Sumitomo Metal Industries Co., Ltd. Agent Patent attorney Noboru Kono

Claims (1)

[Claims] 1. A wire drawing die and a guide member having a gap approximately equal to the exit side diameter of the wire rod are provided on the exit side of the wire drawing die, and a flaw detection device placed between the two is used for defect detection. A wire rod flaw detection method characterized by: