JPH0854356A - Water detecting type flaw detecting agent and its method - Google Patents

Abstract

PURPOSE:To inspect an object to be inspected without contaminating the object nor requiring any drying process after washing the object with water by preparing a water detecting type flaw detecting agent by mixing specific amounts of a white fine inorganic powder and a water-soluble dye with a volatile solvent. CONSTITUTION:A volatile solvent is used for quickly drying a flaw detecting agent after application so that a dried film of white fine inorganic powder through which water can be sucked up by a capillary action can be formed and pentane, methanol, ether, etc., can be used as the solvent. The whiteness of the fine inorganic powder is required to make a colored indication pattern easily seen against a white background and an inorganic matter is used for the fine powder, because, when an organic matter is used, the powder is dyed and no sufficient contrast can be obtained. It is desirable to adjust the grain size of the powder to >=10mum so that water can be sucked out by a capillary action and the mixing ratio of fine powder to 5-60wt.%, because the whiteness becomes lower when the ratio is lower than 5% and the powder cannot be applied easily when the ratio becomes higher than 60%. The water-soluble dye spreads along the fine powder after it dissolves in water and is colored by visible light and is adsorbed to and immobilized on the surface of the powder. The mixing ratio of the dye can be adjusted to 0.05-5wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flaw detection agent for detecting a defect opened on the surface of an inspection object and a flaw detection method therefor. In addition, in the present invention, the defect means a crack such as a crack or a hole existing on the surface of the inspection object.

[0002]

2. Description of the Related Art A penetrant flaw detection test method is a typical method for detecting defects opened on the surface of an inspection object. This method
After applying a red or fluorescent penetrant to the surface of the inspection object and permeating the inside of the defect, the excess penetrant remaining on the surface of the inspection object is washed off with water or a volatile cleaning solution, and then the inspection is performed. The surface of the object is coated with a developing solution in which white inorganic fine powder is dispersed in a volatile solvent to form a thin film of white inorganic fine powder, and the penetrant that has penetrated inside the defects is sucked out to the surface and enlarged. By forming a defect indicating pattern of red or fluorescent color on a white background,
This is a method of detecting the presence of a defective portion. The penetrant used for this penetrant flaw detection agent forms a large amount of red dye and fluorescent dye to improve the distinguishability, as well as an organic solvent to dissolve them, a solvent to improve the penetrability, and an indicator pattern. It is composed of a non-volatile solvent for improving the cleaning property and a surfactant for improving the water washability. Although the penetrant testing method using this penetrant is a method with high detection sensitivity for defects, if water etc. enters the opening defect on the surface of the inspection object, the penetrant will not enter the defect and flaw detection There is a drawback that it becomes impossible, and drying is always required after washing with water. When the humidity is high or after the dew point is generated, before the permeation treatment, the inside of the defect is sufficiently dried before the inspection. In addition, the amount of penetrating liquid applied to the inspection object is
The amount far exceeds the amount required for defect detection, and when inspecting large inspection objects, a large amount of colored waste liquid is generated when the penetrant is removed by washing with water, and the wastewater treatment is also a difficult task. Has become. Further, there are many problems that it is difficult to apply to an inspection object such as plastics that is difficult to be colored, and that it requires a great deal of labor for decolorization after application. In terms of work, three steps are required: a permeation treatment for applying a permeation liquid, a cleaning treatment for removing the permeation liquid, and a development treatment for applying a development liquid.

[0003]

According to the present invention, there is little pollution due to coloring of the penetrant liquid, there are few environmental and occupational health problems, and the drying treatment can be omitted after washing with water before inspection. The present invention provides a flaw detection agent and a flaw detection method, that is, a new flaw detection agent and a flaw detection method capable of simplifying a work process.

[Means for solving the problem]

The inventors of the present invention sucked out water entering the defect by washing with water with a fine inorganic white powder containing a dye, and the sucked water dissolved the dye to form a defect on the white coating film. It was found that defects could be detected by forming an instruction pattern. The present invention comprises a volatile solvent, a white inorganic fine powder and a water-soluble dye insoluble in the solvent, wherein the white inorganic fine powder is 5 to 60% by weight and the water-soluble dye is 0.05.
It is a water detection type flaw detection agent (hereinafter, simply referred to as a flaw detection agent) containing up to 5% by weight. Further, the flaw detection method of the present invention is characterized in that after infiltrating water into the inspection object surface, the surface is dried, then this inspection agent is applied and dried, and defects of the inspection object are detected by color development of the coating film. This is a flaw detection method. Although the basic principle of the flaw detection method of the present invention is the same as that of the penetrant flaw test, in the conventional penetrant flaw test, a special penetrant having a red or fluorescent color is used, whereas in the present invention, a special penetrant is used. The difference is that water is used instead of.

The volatile solvent used in the flaw detection agent of the present invention is
It is used to form a dry coating film of white inorganic fine powder that can be rapidly dried after being applied with a flaw detection agent and causes capillary phenomenon. In addition, the reason why the color of the inorganic fine powder to be dispersed is white is that a sufficient contrast is obtained and the legibility is easy to see when the colored indicator pattern has a white background. The reason why the inorganic fine powder is used is that when the organic powder is used, the organic powder is dyed with the dispersed dye, so that sufficient contrast cannot be obtained. Regarding the particle size of the white inorganic fine powder, water is sucked out by capillary action,
Since the particle size must fulfill the function of expanding, it is preferable that the particle size is as small as possible.
It is desirable that the thickness is μm or less.

As the white inorganic fine powder, those having a high whiteness and having a large effect of adsorbing the dye colored by contact with water are preferable in order to improve the contrast of discrimination between the defect and the sound portion. For example, magnesium carbonate, calcium carbonate, barium carbonate, magnesium hydroxide, magnesium oxide, calcium oxide, titanium oxide, silicic acid, magnesium silicate, synthetic aluminum silicate, acid clay, kaolin, white fine powder such as bentonite is preferable, You may use these, mixing several types. The amount of the white inorganic fine powder is preferably in the range of 5 to 60% by weight, more preferably 20 to 50% by weight. If it is less than 5% by weight, the whiteness of the background is weak and problems such as difficulty in distinguishing between defective parts and sound parts occur. If it exceeds 60% by weight, white inorganic fine powders are dispersed in a volatile solvent. It is not preferable because it is difficult to apply and it becomes difficult to apply.

The water-soluble dye is dissolved in water and develops a color with visible light, then spreads along the white inorganic fine powder and is adsorbed and fixed on the surface thereof. The particles of the water-soluble dye are selected to be as fine as possible and are used by uniformly dispersing them.
Examples of water-soluble dyes include acid dyes, basic dyes, direct dyes, acid mordant dyes, reactive dyes, and food dyes. For example, acid dyes include Brilliant Scarlet 3B, Aliz
arine Direct BlueAGG, Indigo Carmine Blue G, Acid
Milling Cyanine 5R etc. are available. As a basic dye,
Cation Red 6B, Cation Pink FG, Crystal Violet, Met
There are hylene Blue B etc. As a direct dye, Direct
Fast Scarlet 4BS, Benzopurpurine 4B, Direct Fast O
renge S, Direct Rhoduline Red B, Chlorantine Fast
Red 6BLL, SiriusRed 4B, Sirius Supra Red Violet R
L, Sirius Supra Violet BL, Direct Sky Blue 5B, etc. Acid mordant dyes include Chrome Orange A, Chr
ome Orange GR, Chrome Red B, Chrome Brilliant Red
B, Chrome Brilliant Violet R, Chrome Brown PG, etc. can be mentioned. As a reactive dye, Reactone Red
2B-F, Procion Rubine BS, Cibacron Violet F2R-A, P
There are rocion Brilliant Blue RS etc. As food dyes, food red No. 2, food red No. 3, food red No. 1
No. 02, food red No. 103, food red No. 104, food red No. 105, food red No. 106 and the like. If the amount of the water-soluble dye is in the range of 0.05 to 5% by weight, it can be used as a water detection type flaw detection agent, but the deeper the coloring is, the easier it is to visually identify the defective part and the sound part. Good, and more preferably 0.5 to 5% by weight. 0.
If it is less than 05% by weight, it is difficult to distinguish the defective part from the sound part due to weak coloring due to contact with water, and if it exceeds 5% by weight, the bag is soiled with a dye, so that the defective part and the sound part are distinguished from each other. There is a problem that it becomes difficult to do, which is not preferable.

As the volatile solvent, those having good volatility and low viscosity are preferable, and pentane, hexane, heptane,
Hydrocarbons such as octane, toluene and xylene, alcohols such as methanol, ethanol and propanol, ketones such as acetone, and other chlorine-based solvents such as 1.1.1. Trichloroethane and organic solvents such as ethers and esters. These solvents may be used alone or in combination of two or more. The volatile solvent does not substantially contain water, and it is necessary that the water-soluble dye dissolves and does not develop color.

The flaw detection agent of the present invention is
It can be easily prepared by mixing a white inorganic fine powder, a water-soluble dye, and a volatile solvent, but it is also possible to add a commercially available dispersant, if necessary, and it is sufficiently dispersed when the dispersant is added. A flaw detector can be obtained. As the dispersant, commercially available sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene fatty acid ester, nonionic surfactant such as polyoxyethylene alkyl ether, dioctyl sulfosuccinic acid ester salt, alkylbenzene sulfonate, etc. Anionic surfactants may be mentioned. The flaw detection agent of the present invention is usually used in an aerosol type enclosed in an aerosol can or by brush coating. Further, the order of addition of the constituents when preparing the flaw detection agent of the present invention does not affect the performance of the flaw detection agent.

The flaw detection method of the present invention will be described in detail below. First, if necessary, oil and fat as a pretreatment,
Clean the surface by removing scales, dirt and other deposits. Next, water is applied to the surface of the inspection object so that water penetrates into the defect. When the surface has poor wettability, water containing a commercially available surfactant may be used. It should be noted that this operation can be omitted when the cleaning treatment is performed with water, or when it is already known that water is present in the defect. Next, the water on the surface of the inspection object is wiped off with a dry cloth or dried with air or the like to the extent that the water that has penetrated into the defects remains, and then the flaw detection agent of the present invention is applied. As the volatile solvent in the flaw detection agent evaporates, a coating film of white inorganic fine powder containing a water-soluble dye is formed. The water remaining in the defect is sucked to the surface by the capillary action of the inorganic fine powder. The water sucked out dissolves the water-soluble dye,
Color develops, forming a brightly colored defect indicator pattern on a white background. The design pattern of the defect is visually observed.

[0011]

EFFECTS OF THE INVENTION Since the flaw detection agent of the present invention uses water as a substitute for the penetrant liquid in the penetrant flaw detection test, it contaminates the inspection object, the inspector's clothes, the inspection place, etc., with the penetrant liquid during the inspection. And the problem of environmental pollution is reduced. Further, there is no coloring and contamination of an inspection object that is difficult to be decolorized when a conventional penetrant is used, or an inspection object such as a tank for containing a transparent liquid or food. Furthermore, the greatest advantage is that after the water is washed to clean the inspection object, the inspection agent of the present invention can be immediately applied to perform the inspection inspection if the surface is dried, so that the inspection time can be shortened. Moreover, the indicator pattern of the defect using the flaw detection agent of the present invention develops color by contact with the water-soluble dye contained in the flaw detection agent and the water that has penetrated into the defect, and thus has a high sensitivity as with the penetration flaw detection agent. Defects can be detected.

[0012]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. Examples 1-5 Commercially available magnesium carbonate fine powder in a 1 liter container
(Particle size 1 to 3 μm) 30 g (10 parts by weight), titanium oxide fine powder (particle size 0.3 to 0.7 μm) 45 g (15 parts by weight) and silicate fine powder (particle size 1 to 2 μm) 6 g ( 2 parts by weight) was mixed and mixed with the powder as a water-soluble dye.
No. 4 (manufactured by Sanei Chemical Industry Co., Ltd.) 3 g (1 part by weight), normal heptane 213 g (71 parts by weight) as a volatile solvent, and sorbitan monooleate 3 g (1 part by weight) as a dispersant.
And 3 at 1500 RPM using a regular stirrer
The flaw detection agent of Example 1 of the present invention was obtained by stirring and dispersing for 0 minutes. The obtained flaw detection agent was filled in an aerosol can of a 300 ml container at a weight ratio of 1: 1 of the flaw detection agent and LPG. Next, for a stainless welded inspection object having a size of surface defects of 50 to 300 μm of length 150 mm × width 30 mm × thickness 5 mm, a cleaning liquid is sufficient for adhering substances such as fats, scales, and dirt on the surface of the inspection object. After removing
As a permeation treatment, normal water was applied to the surface of the inspection object and left for 7 minutes to permeate the water into the defect. When the water content on the surface of the inspection object was dried during that time, water was applied again. Next, the excess water remaining on the surface of the inspection object was completely wiped off with a dry waste cloth, and then the flaw detection agent was applied to the entire surface of the inspection object at a coating amount of 40 g / m ² . Then, after 10 minutes, the indicator pattern appeared on the coating film of the white inorganic fine powder dried by evaporation of the volatile solvent of the flaw detection agent was visually observed. Table 1 shows the composition of the flaw detection agent and the result of the flaw detection inspection. Defects on the surface of the inspected object were clearly confirmed to be colored in a bright red color against a white background. Hereinafter, a similar flaw detection test was performed by using the flaw detection agent having the composition shown in Table 1 in the same manner, and the results are shown in Table 1.

Comparative Example 1 In Example 1, a commercially available penetrant PS, a wash RQ and a developer DS (all manufactured by NOF CORPORATION: TASETO Color Check (registered trademark)) were used as a dye penetrant flaw detector. Using the same size stainless steel welding inspection product,
Apply the penetrant liquid to the entire surface of the inspection object, and after 7 minutes, remove the excess penetrant liquid with a cloth soaked in the cleaning liquid, and apply 40 g / m ^{2 of} developer
Apply the coating amount of 1 and the instruction pattern appearing on the developed coating is 1
It was visually observed after 0 minutes. The results are shown in Table 1.

Comparing the pattern of defects on the surfaces of Examples 1 to 5 with the pattern of Comparative Example 1, it was confirmed that the detection sensitivities of defects were equivalent.

Comparative Examples 2 to 3 A flaw detection agent having a composition different from that of the present invention shown in Table 1 was prepared in the same manner as in Example 1, and the same test was carried out. In Examples 3 to 5, the defective portion on the surface of the inspection object was clearly confirmed to be colored with a bright red color on a white background. In addition, the defect detection sensitivity was similar to that of commercially available flaw detection agents.

[0016]

[Table 1]

Claims (2)

[Claims] 1. A white inorganic fine powder comprising 5 to 6 of a volatile solvent, a white inorganic fine powder and a water-soluble dye insoluble in the solvent.
A water-detecting flaw detection agent, characterized by containing 0% by weight and a water-soluble dye of 0.05 to 5% by weight. 2. The surface of the inspection object is permeated with water and then dried, and then the water detection type flaw detection agent according to claim 1 is applied and dried, and a defect of the inspection object is detected by color development of the coating film. A flaw detection method characterized by the above.