JPH0361854A - Method and apparatus for continuous magnetic powder flaw test for rod-shaped angular steel piece - Google Patents

Abstract

PURPOSE:To make it possible to inspect defects quickly and stably by keeping the diagonal line of the cross section of a rod-shaped angular steel piece horizontally, and continuously performing magnetic flaw detection. CONSTITUTION:The diagonal line of the cross section of a rod-shaped angular steel piece 1 is kept at the horizontal state. The steel piece 1 is moved in the axial direction. Magnetic powder liquid is applied on an upper slant surface 2 quickly and uniformly with a first magnetic-powder spraying device 5. The steel piece 1 is magnetized with a first magnetizing device 9, and magnetic flaw detection is performed. Then the flaw detection of a lower slant surface 3 is performed by the same way with a second magnetic powder spraying device 13 and a second magnetizing device 17. The defects of the four surfaces are detected quickly and highly accurately by the continuous flaw detection including the uniform application.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a continuous magnetic particle testing method and apparatus for bar-shaped square steel pieces.

The present invention is used to detect defects such as cracks on or near the surface of a rectangular steel piece having a relatively large cross section, such as a steel billet.

[Conventional Technique vR] In magnetic particle testing of square steel bars such as billets, defects can be continuously detected while feeding the square steel bar in the longitudinal direction in a posture where one diagonal of the square section is horizontal. It is widely practiced. To apply magnetic powder liquid to the surface of the rectangular steel bar in the above posture, spray the magnetic powder liquid onto the two upper inclined surfaces of the rectangular steel bar from one or more magnetic powder spraying ports placed above the rectangular steel bar. There is a method. In this method, the magnetic powder liquid flows from the upper inclined surface to the lower inclined surface, and it is possible to apply the magnetic powder liquid to four surfaces by one spraying of the magnetic powder liquid. Another application method is to spray the magnetic powder liquid onto one upper inclined surface of a bar-shaped square steel piece from the magnetic powder liquid dispersion port similar to the above method, and then spread the magnetic powder liquid onto one surface of the lower inclined surface on the same side as the upper inclined surface on which the magnetic powder liquid was sprayed. There is a method of coating two surfaces on one side by applying with a flow of magnetic powder liquid. Depending on the magnetization conditions and observation conditions, these magnetic powder liquid application methods are used alone or in combination. In addition, when immediately after forming a magnetic particle pattern on two surfaces, an upwardly inclined surface and a downwardly inclined surface, on one side, when flaws are detected on two surfaces, an upwardly inclined surface and a downwardly inclined surface on the opposite side, the previously formed magnetic particle pattern disappears. It must be ensured that it is not disturbed or disturbed. In such a case, in order to prevent the magnetic powder liquid from being scattered on the surface where the magnetic particle pattern is formed, a mechanism in which the magnetic powder liquid dispersion port follows the side surface of the bar-shaped square steel piece is used to prevent the magnetic powder liquid from spreading on the upper and lower inclined surfaces of one side. It is also practiced to apply magnetic powder liquid to only two sides.

[Problems to be Solved by the Invention] In both of the above-mentioned magnetic powder liquid application methods, magnetic powder liquid is sprayed onto the upper inclined surface from a magnetic powder liquid spraying port fixed above the bar-shaped square steel piece or equipped with a tracking mechanism, and then applied to the lower surface of the bar-shaped square steel piece. The downward slope is coated using flowing magnetic powder liquid. By the time the magnetic powder liquid reaches the lower end of the downwardly inclined surface, the magnetic particles are attracted to the defective portion or remain on the surface of the bar-shaped square steel piece. Due to this, the concentration of the magnetic powder liquid that has reached the downwardly inclined surface is considerably lower than the concentration of the magnetic powder liquid immediately after the magnetic powder liquid is sprayed. As a result, the magnetic particle pattern on the downwardly inclined surface becomes chain-like or becomes unclear compared to the upwardly inclined surface, resulting in a decrease in flaw detection accuracy. In addition, it takes a long time for the magnetic powder liquid sprayed from the magnetic powder scattering port to flow from the upper inclined surface to the lower inclined surface, resulting in a large amount of magnetic powder being sprayed, a decrease in the feeding speed of the bar-shaped square steel piece, or a long magnetization time. Measures such as these must be implemented. Therefore, problems such as longer inspection time and larger magnetization devices have arisen. Such problems become more severe as the cross-sectional area of the rectangular steel bar increases.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method and apparatus for continuous magnetic particle flaw detection testing of a rectangular bar-shaped steel piece, which can uniformly apply magnetic powder liquid to the four sides of the rectangular steel bar in a short period of time.

[Means for Solving the Problems] The continuous magnetic particle flaw detection test method for a rectangular steel bar according to the present invention involves spraying magnetic powder liquid on two upper inclined surfaces of the rectangular steel bar, magnetizing the rectangular steel bar, and detecting the upper inclined surface of the rectangular steel bar. A magnetic powder pattern is formed on two surfaces of the bar-shaped square steel piece, and then magnetic powder liquid is sprinkled on the two downwardly inclined surfaces of the bar-shaped square steel piece to magnetize the bar-shaped square steel piece and a magnetic powder pattern is formed on the two downwardly inclined surfaces of the bar-shaped square steel piece.

The amount of spraying on the lower inclined surface, the feeding speed of the rectangular steel bar, the magnetization time, the magnetization device, etc. may be the same as the conditions for dispersing on the upper inclined surface. Further, the timing of dispersing and magnetizing the downwardly inclined surface is the same as when the magnetic powder liquid is dispersed from the upper surface and the upwardly inclined surface is inspected for flaws.

The continuous magnetic particle flaw detection test device for square steel bars of the present invention includes a fW1 powder spraying device that sprays magnetic powder liquid on two upwardly inclined surfaces of a square steel bar, and a U-shaped powder dispersion device that is placed directly below the square steel bar and faces upward. a first ti converting device equipped with a core of The provided second magnetization devices are sequentially arranged along the direction of transport of the bar-shaped square steel piece.

[Operation] After forming the magnetic powder pattern on the upper inclined surface, the magnetic powder liquid is sprayed only on the lower inclined surface, so that the magnetic powder liquid is applied almost uniformly and in a short time. Furthermore, the magnetic particle pattern on the upper inclined surface does not disappear or become disordered, and the magnetic particle pattern on the lower inclined surface does not become chain-like or become unclear compared to the upper inclined surface.

[Example] Fig. 1 shows an example of the apparatus of the present invention, and is a schematic perspective view of an apparatus that continuously tests steel billets for magnetic particle flaw detection.

As shown in the drawing, a first magnetic powder spraying device 5 that sprays magnetic powder liquid on two upper inclined surfaces 2 of the billet 1, a first magnetization device 9 that magnetizes the billet 1, and two lower inclined surfaces 3 of the billet 1 A second magnetic powder spraying device 13 that sprays magnetic powder liquid onto the surface and a second magnetization device 17 that magnetizes the billet 1 are sequentially arranged along the billet 1 transport direction.

The first magnetic powder liquid dispersing device 5 has six nozzles 7 directed downward.
is attached to the header 6. Magnetic powder liquid is force-fed to the header 6 from a magnetic powder liquid tank (not shown).

The first magnetization device 9 includes an upwardly facing U-shaped core 10 and a magnetization coil 11 wound around the core, and the magnetization coil 11 is connected to an AC magnetization power source (not shown).

In the second magnetic powder liquid dispersion device 13, a pair of nozzles 15 facing the downward inclined surface 3 are attached to a bracket 14. The bracket 14 is fixed to a support member 22, which will be described later. Magnetic powder liquid is force-fed to the nozzle 15 from a magnetic powder liquid tank (not shown).

The second magnetizing device 17 has the same structure as the first magnetizing device 9, and consists of a downwardly facing U-shaped core 18 and a magnetizing coil 19 wound around it. (not shown) is connected.

The billet 1 is supported by a plurality of hourglass-shaped transfer rolls 20 and transferred. The transfer roll 20 is rotationally driven by a motor with a speed reducer (not shown).

The drum-shaped roll between the first magnetization device 9 and the second magnetic powder liquid dispersion device 13 is a follower roll 21, and as shown in FIG. 2, it is rotatably supported by a U-shaped support member 22. The follower roll 21 rotates following the running of the billet 1.

The support member 22 is attached to a substrate 25 via a coil spring 24. On the other hand, an air cylinder 29 is fixed to a frame 27 arranged below the follower roll 21. A rod 30 of the air cylinder 29 is connected to one end of an L-shaped arm 32 swingably attached to the frame 27 . The substrate 25 is fixed to the other end of the L-shaped arm 32. By the operation of the air cylinder 29, the follower roll 21 and the nozzle 15 move up and down in unison. When the follower roll 21 rises to a position where it supports the billet, the nozzle 15 is automatically positioned at a distance suitable for spraying the magnetic powder liquid relative to the billet 1.

In the continuous magnetic particle flaw detection apparatus configured as described above, the transfer roll 20 and the follower roll 21 support the billet 1 in a posture in which one diagonal of the corner cross section is horizontal, and the transfer roll 20 supports the billet 1 in the longitudinal direction of the billet 1. send to The first magnetic powder liquid spraying device 5 spreads magnetic powder liquid onto two upper inclined surfaces 2 of the billet 1. Next, the billet 1 is magnetized by the first magnetization device 9. If there is a defect such as a crack on two surfaces of the upper inclined surface 2, leakage magnetic flux is generated in the defective portion, and magnetic particles are attracted thereto, forming a magnetic particle pattern.

Next, magnetic powder liquid is sprayed onto two of the lower inclined surfaces 3 of the billet 1 by the first magnetic powder liquid scattering device 13, and magnetic powder patterns are formed on the two lower inclined surfaces 3 in the same manner as in the case of the upper inclined surface 2. let

The magnetic particle pattern formed on the defective portion as described above is observed visually by a flaw detector operator and with an industrial television camera. Then, work such as marking and defect removal is performed.

FIG. 3 shows various aspects of the nozzle used in the second magnetic powder liquid dispersing device 13 of the above device.

FIG. 3 (A) A fan-shaped nozzle 35 is arranged so as to jet directly upward toward the lower inclined surface 3 of the billet 1, and by adjusting the ejection pressure and the billet 1 and the nozzle opening 1llL, the lower inclined surface 3
Apply magnetic powder solution only to the

Ejection pressure 0.7 kg/c ro2 Billet-nozzle distance L = 50 mm Fig. 3 (b) Four nozzles 36 are arranged in horizontal parallel to eject directly onto the lower inclined surface 3 of the billet 1, and the ejection pressure is varied. By doing so, the magnetic powder liquid is applied only to the downwardly inclined surface 3.

Ejection pressure 0.5~l, 0kg7cm2 Billet-nozzle distance j1iL = maximum 200mm Fig. 3 (c) Billet 1 Set the nozzle 37 so as to eject directly onto the lower inclined surface 3 of the billet! Arrange the four pieces according to the shape of the
Ejection pressure or pressure between billet 1 and nozzle! By adjusting IIL, the magnetic powder liquid is applied only to the downwardly inclined surface 3.

Ejection pressure 0.7kg/cm2 Billet-nozzle distance 1. = 50mm Figure 3 (d) Billet! Aiming at the lower inclined surface 3, magnetic powder liquid is applied only to the lower inclined surface 3 using a fan-shaped nozzle 38 from diagonally above.

Ejection pressure: 0.7 kg/crQ2 Billet-nozzle distance L = 50 mm Fig. 3 (e) Aim at the lower inclined surface 3 of the billet 1, aim diagonally upward, and apply magnetic powder liquid only to the lower inclined surface 3 using the fan-shaped nozzle 39. .

Ejection pressure 0.7 kg/c+o2 Billet-nozzle distance L = 50 mm FIG. 3 (f) Magnetic powder liquid is applied only to the F inclined surface 3 of the billet 1 through the dispersing port 41 provided at the lower part of the annular tube 40.

Ejection pressure 0.7kg/cm2 Billet-nozzle distance L = 50mm Figure 3 above
For both of the nozzles 35° to 4° shown in (a) to (f), the magnetic powder pattern is much clearer than the conventional case of only scattering on the upper surface, and the magnetization time is also shorter than that of the upper inclined surface without waiting for the magnetic powder to flow. The time required to form a magnetic particle pattern was sufficient.

The nozzles 35, 38, and 39 shown in FIGS. 3(a), (d), (e), and (f) can only be used for billets 1 whose dimensions are approximately constant. However, the third
The nozzles 36 and 37 in Figures (B) and (C) can accommodate a wide range of billet sizes by changing the number of nozzles depending on the size of the billet 1. The nozzles 38 and 39 shown in FIGS. 3A and 3E can supply the magnetic powder liquid to the billet surface in a layered manner, and the scattering of the magnetic powder liquid is small. For this reason, Figure 3 (a), (b) and (c)
Compared to the nozzles 35 to 37 shown in the figure, the consumption of magnetic powder liquid is less. In addition, in the nozzle 38 in FIG. 3(d),
When the magnetic powder liquid is spread along the billet surface, the nozzle 38
There is no need to finely adjust the injection pressure.

[Effects of the Invention] According to the present invention, after the magnetic powder pattern is formed on the upper inclined surface, the magnetic powder liquid is sprayed only on the lower inclined surface, so that the magnetic powder liquid is applied almost uniformly and in a short time. Further, the magnetic particle pattern on the upper inclined surface does not disappear or become disordered, and the magnetic particle pattern on the lower inclined surface does not become dull or unclear compared to the upper inclined surface. Therefore, equivalent flaw detection accuracy can be obtained on both the upper and lower inclined surfaces. As a result, stable defect detection can be carried out, quality control can be facilitated, inspection time can be shortened, and the magnetization device can be downsized.

[Brief explanation of drawings]

Fig. 1 shows an example of the apparatus of the present invention, and shows a schematic perspective view of the apparatus, a perspective view showing details of the second magnetic powder scattering device of the apparatus shown in Fig. 1, and Figs. These are drawings showing various aspects of the nozzle used in the second magnetic powder scattering device. ! ... Rod-shaped square steel piece, 2 ... Upper inclined surface, 3 ... Lower inclined surface, 5 ... First magnetic powder scattering device, 7 ... Nozzle, 9
...First magnetization device, 13...Second magnetic powder shedding device, 1
5... Nozzle, 17... Second magnetization device, 20...
Transfer roll, 21...Following roll, 22--Roll support member, 29...Air cylinder, 32--L-shaped arm, 35-39...Nozzle, 40...Annular tube, 4
1... spout.

Claims (1)

[Claims] 1. Spreading magnetic powder liquid onto the surface of the square steel bar while feeding the square steel bar in the longitudinal direction with one diagonal of the corner cross section being horizontal, and then magnetizing the square steel bar. In a magnetic particle flaw detection test that continuously detects defects, magnetic powder liquid is sprayed on two upper inclined surfaces of a square steel bar, magnetizing the square steel bar and forming a magnetic particle pattern on the two upper inclined surfaces. Continuous magnetic particle flaw testing of a bar-shaped square steel piece, characterized in that magnetic powder liquid is then sprinkled on two downwardly inclined surfaces of the bar-shaped square steel piece, magnetizing the bar-shaped square steel piece and forming a magnetic particle pattern on the two downwardly inclined surfaces of the bar-shaped square steel piece. Test method. 2. While feeding the bar-shaped square steel piece in the longitudinal direction with one diagonal of the corner cross section being horizontal, sprinkle magnetic powder liquid on the surface of the bar-shaped square steel piece, and then magnetize the bar-shaped square steel piece to continuously create defects. A magnetic particle flaw detection test device for performing detection includes a first magnetic powder liquid dispersion device that sprays magnetic powder liquid on two upwardly inclined surfaces of a bar-shaped square steel piece, and a U-shaped core that is placed directly below the bar-shaped square steel piece and points upward. First magnetization device, 2 of the downwardly inclined surface of the bar-shaped square steel piece
A second magnetic powder liquid dispersion device for dispersing magnetic powder liquid onto a surface, and a second magnetization device provided with a U-shaped core arranged directly above the bar-shaped square steel piece and directed downward are arranged in sequence along the transport direction of the bar-shaped square steel piece. Continuous magnetic particle flaw detection testing equipment for bar-shaped square steel pieces.