JPH02242142A - Detection and recording of opening defect for porous body - Google Patents

Abstract

PURPOSE:To enable detection and recording of an opening defect of a porous body by a method wherein a surface to be observed is impregnated with a volatile solvent while being volatilized to inspect a reflection pattern by eyes while a transfer recording paper is applied which react with a residual solvent at an opening defect to color. CONSTITUTION:When applied on a surface to be observed of a porous body 1, a volatile solvent 3 permeates an opening defect 2 being vaporized and brightens white in the surface in the vicinity thereof as compared with other parts with a quick volatilization at the part. So, the existence of the surface can be observed to a certain extent by a visual inspection. Where the solvent permeating the part 2 alone is left, the solvent looks black to enable detection. Moreover, when a transfer recording paper 4 is applied, the defect part 2 can be recorded as transfer part 6 coloring a reaction part with a volatilization of the solvent yet to volatilize. The solvent 3 permeating the defect vaporizes with the passage of time and finally vanishes completely from the porous body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for detecting and recording an opening defect in a porous body that cannot be subjected to penetrant testing.

[Conventional technology]

Nuclear power plant cores use porous graphite or carbonaceous materials. From the viewpoint of safety, it is necessary to non-destructively detect defects on the surface and inside of these materials, and to select and eliminate materials with defects of dimensions outside the permissible limits. It is extremely important to detect defects not only inside the material but also open defects that exist on the surface of the material where stress is high.

Conventionally, non-destructive testing of graphite materials has been almost impossible, and the reality is that a 100% guarantee test (destructive test) has been carried out.

In nondestructive testing, penetrant testing is the most widely known method for detecting open defects. What is penetrant testing?
Defects on the surface of the test item are removed by capillary action.
This is a method of creating an enlarged image and observing it with the naked eye.

The basic shaking motion is shown in FIG. 4. First, the penetrating liquid is applied to the surface of the specimen 7 or the specimen 7 is immersed in the penetrating liquid, so that the penetrating liquid soaks into the opening defect 2. (Fig. 4 (a)), once the opening defect 2 is filled with the penetrating liquid, remove the penetrating liquid adhering to the surface of the specimen 7 with water or cleaning liquid (Fig. 1 (b)), and then Then, a thin layer of white fine powder developer is applied to the surface of the specimen 7. The penetrating liquid remaining in the opening defect 2 is sucked out by the developer as shown in FIG. 1(c) and spreads over the surface, forming an indication pattern that matches the shape of the defect to some extent. Since the penetrating liquid contains a fluorescent dye or a red dye, the area from which the penetrating liquid has been sucked out emits a yellow-green color or exhibits a red color, making it possible to observe the opening defect 2 with the naked eye (see Fig. 1). d)).

[Problem to be solved by the invention]

However, when such a penetrant test is applied to a porous material such as graphite, a large amount of penetrant liquid penetrates between the particles, and when the developer is applied, the liquid that has penetrated between the particles as well as the opening defects is sucked out. There was a problem in that an indicator pattern was formed over the entire surface of the observation surface to be inspected, making it impossible to accurately identify the opening defect 2. On the other hand, the inability to completely remove the penetrating liquid that has entered the graphite during penetrant testing and the developer that has adhered to the surface after the test is completed is another reason why it is considered difficult to apply the flaw detection test.

The present invention has been made in view of the above-mentioned points, and its object is to provide a method for detecting and recording an opening defect that can be applied to a porous body by using a novel penetrating liquid.

[Means to solve the problem]

According to the present invention, the above-mentioned purpose is to 1) impregnate and volatilize the volatile solvent 3 on the observation surface of the porous body 1 including the open defect portion 2 and the non-defect portion 5, and visually observe the light reflection pattern on the observation surface; and 2) impregnating the observation surface of the porous body 1 including the open defect portions 2 and the non-defect portions 5 with a volatile solvent 3, and volatilizing the volatile solvent 3 from the non-defect portions 5; While the unvolatilized volatile solvent 3 remains in the defective part 2, the volatile solvent 3 is applied to the observation surface.
This is achieved by attaching a sheet of transfer recording paper 4 which is reactively colored.

[For production]

When the observation surface is impregnated with a volatile solvent, the solvent permeates both the open defect portion 2 and the non-defect portion 5. In non-defect areas, the solvent penetrates between the particles. At this time, the penetration depth of the non-defect part 5 is small because the gaps between particles are small, whereas the penetration depth of the solvent is large in the open defect part 2 because the opening is large.

The infiltrated solvent then vaporizes and volatilizes, but due to the above-mentioned difference in the infiltration depth, a difference occurs between the open defect area 2 and the non-defect area 5 at the end of volatilization, resulting in the presence or absence of the solvent on the observed surface. This causes a difference in the amount of light reflection between the opening defect portion 2 and the non-defect portion 5. Furthermore, if a transfer recording paper that reacts with a volatile solvent is attached to the observation surface when the presence or absence of a solvent occurs between the opening defect area 2 and the non-defective area 5, vaporized vapor from the opening defect area 2 will be transferred to the transfer recording paper. It reacts with the portion corresponding to the opening defect and colors it.

The transfer recording paper can detect and record an opening defect at the same time.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

(Example 1) FIG. 1 is a process diagram according to an example of a method for detecting an opening defect portion.

In FIG. 1, 1 is a porous body, 2 is an open defect portion, 3 is a volatile solvent, and 5 is a non-defect portion.

In order to detect the opening defect 2, a volatile solvent 3 (for example, acetone, alcohol, etc.) is applied or sprinkled on the observation surface of the porous body 1, as shown in FIG. 1(b). The sprayed volatile solvent 3 permeates into the opening defect portion 2 while vaporizing as shown in FIG. 1(c).

At this time, a part of the volatile solvent 3 spread around the opening defect 2 permeates into the inside of the opening defect 2, so that the surface near the opening defect 2 finishes vaporizing and volatilizing earlier than other parts.

At this stage, the presence or absence of defects is observed to some extent.

The area around the opening defect glows white. Next, the volatile solvent 3 that has been sprayed is vaporized and volatilized as shown in Figure 1(d), forming a porous body l.
The solvent completely disappears from the surface of the opening defect 2, and only the solvent that has penetrated into the opening defect 2 remains. When observed with the naked eye in such a state, only the portion where the defect exists appears black, and the opening defect portion 2 can be detected.

The volatile solvent 3 that has penetrated into the interior of the opening defect vaporizes and evaporates over time, and finally disappears completely from the porous body 1 as shown in FIG. 1(e).

(Example 2) FIG. 2 is a process diagram showing an example of a method for recording an opening defect portion. The meanings of the symbols in FIG. 2 are the same as in FIG. Second
In the figure, 4 is a transfer recording paper, and 6 is a transfer section. Transfer recording paper 4 such as thermal paper is porous with the volatile solvent 3 completely vaporized and volatilized from the non-defective area 5 of the porous body 1 and unvolatilized volatile solvent 3 remaining in the open defect area 2. Attach a note to material 1. When the unvolatilized volatile solvent 3 evaporates and evaporates, the solvent molecules react with the transfer recording paper 4 and color the reaction portion of the transfer recording paper 4 to form a transfer portion. In this way, the opening defect part 2
is transferred onto the transfer recording paper 4. This recording method serves as a method for detecting an aperture defect portion as well as a recording method.

FIG. 3 shows an example of transfer recording of an aperture defect portion onto a transfer recording paper, and this example is intended for a fairly large defect. It can be seen that parts that cannot be detected by naked eye observation can also be detected.

〔Effect of the invention〕

According to the present invention, 1) a volatile solvent is impregnated and volatilized on the observation surface of the porous body including open defect areas and non-defect areas, and the light reflection pattern on the observation surface is visually observed; The aperture defect can be clearly detected due to the difference in the amount of light reflected in the area. 2) After impregnating the observation surface of the porous body including open defect areas and non-defect areas with a volatile solvent, and volatilizing the volatile solvent from the non-defect areas, apply the unvolatilized volatile solvent to the open defect areas. A transfer recording paper that reacts and colors with a volatile solvent is attached to the observation surface while the aperture remains, so the part corresponding to the aperture defect is colored by reaction with the volatilized solvent, and the aperture defect is transferred. It becomes possible to detect and record.

[Brief explanation of drawings]

FIG. 1 is a process diagram relating to an embodiment of a method for detecting an opening defect,
FIG. 2 is a process diagram of an embodiment of a method for recording an opening defect,
FIG. 3 is a diagram showing a transfer pattern of an opening defect, and FIG. 4 is a process diagram showing a conventional penetrant testing method. 1: Porous body, 2: Open defect, 3: Volatile solvent, 4:
Transfer recording paper, 5: non-defective area, 6: transfer area. (e) Figure 1 (a) (b) (d) Figure 4

Claims (1)

[Claims] 1) A porous material characterized in that a volatile solvent is impregnated and volatilized on the observation surface of a porous body including open defect areas and non-defect areas, and the light reflection pattern on the observation surface is visually observed. A method for detecting an opening defect in a mass body. 2) After impregnating the observation surface of the porous body, including open defect areas and non-defect areas, with a volatile solvent and volatilizing the volatile solvent from the non-defect areas, unvolatilized volatile solvent is left in the open defect areas. 1. A method for recording opening defects in a porous body, characterized by attaching a sheet of transfer recording paper that is colored by reaction with a volatile solvent to the observation surface in a remaining state.