RU2694721C1 - Contact liquid for ultrasonic flaw detection - Google Patents

Abstract

FIELD: defectoscopy.

SUBSTANCE: invention relates to non-destructive testing using contact liquid, which is used at low temperatures in railway transport. Disclosed is contact liquid for ultrasonic flaw detection, which contains components at following ratio, wt%: isopropyl alcohol 35–55; ammonium acetate 20–35; process additives not more than 2.0 and water – balance.

EFFECT: technical result consists in improvement of acoustic contact with a controlled object at low to minus 65–70 °C ranges of operating temperatures and high speeds of movement of train, higher stability of physical properties of contact liquid, possibility of long-term storage of contact liquid, during which it retains all its properties and properties.

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Description

The invention relates to the field of obtaining the composition of antifreezing contacting liquid (hereinafter referred to as NKZH), intended for providing acoustic contact with ultrasonic non-destructive testing with removable means of railway railway track testing in transit, elements of switches and welded joints at negative ambient temperatures.

Contact liquids are used in virtually all contact studies to facilitate the transmission of a sound pulse from a sensor to a test sample and the detection of defects. Defects are cracks, delaminations, and other, as a rule, internal rail damage detected by ultrasonic, magnetic, and other flaw detection devices.

The following terms and definitions are used throughout the description text:

- Ultrasonic non-destructive testing of rails - a method of acoustic non-destructive testing, in which devices and devices are used that use the ultrasonic frequency range;

- Acoustic contact - connection of the working surface of the electro-acoustic transducer with the test object;

- Non-freezing contact (contacting) liquid - a means for providing acoustic contact when controlling removable means of rail inspection on the way at negative temperatures;

- Corrosive effects on metals - the ability of components of antifreeze liquid to cause metal corrosion

The technical requirements for the NKZH, developed at the Russian Railways OJSC in August 2016, should comply with the following basic technical characteristics:

- NKZh should not freeze at ambient temperature to minus 55 ° C-75 ° C;

- to ensure stable acoustic contact between the piezoelectric transducers of the removable flaw detector and the surface of the rail head;

- not to destroy the materials of the working bodies of the equipment used (rubber-technical products, organic glass and metal elements), electrical contacts and connections, as well as sealing rings of piezoelectric transducers;

- lack of salt formation on the elements of the flaw-detection equipment;

- to be non-flammable and non-toxic product;

- do not have a strong odor that irritates the mucous membranes of the human respiratory tract;

- do not degrade the coefficient of adhesion of the wheels of the rolling stock with the rail;

- have a sufficiently high evaporability and be biodegradable (at least 80%);

- freely flow through the fluid supply hoses of the flaw detection equipment at positive and negative atmospheric temperatures

- NKZh should have a dynamic viscosity at a temperature of minus 50 ° C not higher than 1 Pa-s;

- NKZh should have a density of 0.7-1.5 g / cm ³ , when the ambient temperature is from + 40 to minus 55 ° С;

- NKZh should provide the value of the friction coefficient in the "wheel - rail" system directly in the contact zone after the application of NKZH on the rail in the range from 0 ° C to minus 50 ° C not less than 0.25.

A patent search showed that no inventions (patents) protecting NKZh with such a complex of technical characteristics were found, therefore the problem of creating NKZH is relevant, especially for the northern regions of the country in the field of railway transport.

There are quite a lot of inventions that protect the compositions of contact liquids from the use of metal chlorides as the basis (SU 1379721, 07.03.1988; SU 1471117, 07.04.1989; SU 1525566, 30.11.1989; SU 1631406, 28.02.1991 (the latter two also contain methyl alcohol); SU 1652905, 05/30/1991; RU 2652380, 04/26/2018; SU 1652905, 05/30/1991; RU 2366940, September 10, 2009. However, when using metal chlorides, they crystallize from aqueous solutions at low temperatures, which leads to additional pollution by oils and greases, which are formed, for example, in wheelsets and that requires additional removing impurities using a large amount of alcohol.

Known contact fluid for ultrasonic testing, containing components in the following ratio, wt. %: ethyl or butyl alcohol 0.5-15; propylene glycol 85-99,5 (SU 1455870, 12/10/1986).

A significant drawback of the known liquid is the possibility of measuring under conditions of temperatures up to minus 40 ° C, which limits its use only to control the quality of laminated laminated structures and products made of laminated plastics.

Known contact fluid for ultrasonic testing, containing the following components, wt. %: methyl alcohol 20-30, kerosene or gasoline 20-25, calcium chloride 20-25, sodium chloride 3-5, surfactant 1.5-3, hexamine (corrosion inhibitor) 0.001-0.1, depressant 0.3- 0.5, antistatic 0.001-0.5 and water - the rest (SU 1525566, 11/30/1989).

The specified contact liquid is selected as the closest analogue to declare.

Known contact fluid provides the ability to conduct measurements at low temperatures down to minus 60 ° C. However, gasoline and kerosene contained in the liquid composition are polluting substances, which does not allow using this liquid for defectoscopy of overpasses and rail tracks.

Methyl, ethyl and butyl alcohols belong to the series of monohydric primary alcohols of the aliphatic series, are available for use, but as part of the liquids of these analogues, they have significant limitations and low productivity of use at temperatures below minus 60 ° C, in particular in the field of railway transport.

The problem of low flaw detection performance is particularly relevant in the case of monitoring railway lines, the length of which is tens of thousands of kilometers.

Today, in order to take measurements on any part of the track, the measuring teams spend hours waiting for the so-called “window” in a tight train schedule. The increase in flaw detection performance would allow the problem to be solved by combining the movement of flaw detection equipment with the movement of trains.

The technical problem to which the invention is directed, is to create a contact liquid, which allows the process of flaw detection at negative temperatures and at high speeds, close to the speed of the train.

The technical result is to provide reliable acoustic contact with a controlled object at low to minus 65-70 ° C operating temperature ranges and high speeds of the train.

Another technical result is to increase the stability of the physical properties of the contact liquid with a simplified composition.

Another technical result is the possibility of long-term storage of contact liquid, during which it retains all its properties and qualities.

These technical results are achieved by the fact that the contact liquid for ultrasonic flaw detection, containing monohydric primary alcohol of the aliphatic series, technological additives and water, according to the invention additionally contains ammonium acetate, and as alcohol is isopropyl alcohol in the following ratio, wt. %: isopropyl alcohol 35-55; ammonium acetate 20-35; technological additives not more than 2.0 and water else, while technological additives contain: corrosion inhibitor 0.5-1.0 wt. %; for chromaticity the pigment is 0.002-0.006 wt. %; for the smell of perfume 0.02-0.2 wt. %; surfactant 0.1-0.35 wt. %, which is used as predominantly synthanol, neonol or other known surfactants.

Example 1

Contact fluid in the amount of UT is prepared as follows. 3.5 t (35 wt.%) Of ammonium acetate powder are loaded into a container with forced agitation, 3.5 t (35 wt.%) Of isopropyl alcohol and 0.622 wt. % technological additives: corrosion inhibitor 0.5 wt. %; neonol 0.1 wt. %; pigment 0.002 wt. %; perfume 0.02 wt. %, add water to obtain 10 tons of the total amount of solution, the components are mixed until the acetate is completely dissolved and a homogeneous composition is obtained.

The solution of contact fluid is transparent. Liquid freezing point is minus 65 ° С. The resulting product is Packed and sent to storage or sale.

Example 2

All as in example 1, but load 2.0 tons (20 wt.%) Of ammonium acetate powder, add 5.5 tons (55 wt.%) Of isopropyl alcohol and technological additives 1.556 wt. %: corrosion inhibitor 1.0 wt. %; neonol 0.35 wt. %; pigment 0.006 wt. %; perfume 0.2 wt. %, pour water up to 10 tons, the components are mixed until the acetate is completely dissolved.

The freezing temperature of the obtained contact liquid is minus 67 ° C.

Example 3

All as in example 1, but load 30 wt. % ammonium acetate powder, add 45 wt. % isopropyl alcohol and 1.255 wt. % technological additives: (corrosion inhibitor 0.8 wt.% (sodium benzoate); neonol 0.30 wt.%; pigment 0.005 wt.%; perfume 0.15), make up to 10 tons of water, the components are mixed until the acetate is completely dissolved ammonium.

The freezing temperature of the contact liquid is minus 70 ° C.

The proposed liquid has a non-complex composition, is easy to prepare, has the required viscosity due to the fact that at low temperatures it thickens and prevents spreading. The combination of isopropyl alcohol with ammonium acetate provides a synergistic effect, namely: a low freezing point of minus 67-70 ° C, viscosity and contact liquid properties that meet the technical requirements for NKZH, developed by Russian Railways.

As isopropyl alcohol use alcohol according to GOST 9805-84, ammonium acetate according to GOST 3117-78.

Sodium benzoate is preferably used as a corrosion inhibitor; however, other well-known numerous corrosion inhibitors can be used.

Determination of the freezing temperature (solidification) of the contact liquid was carried out according to the standard method, in accordance with GOST 20287-91 “Oil products. Methods for determining the temperature of fluidity and hardening ".

As shown by tests with ultrasonic flaw detection of rails of railway tracks, contact liquids of all compositions have an operating temperature ranging from 0 to minus 70 ° C and an increase in the reliability of acoustic contact when monitoring products, by improving wettability, contact between the object under study and the acoustic device.

Guaranteed shelf life of contact liquid is at least three years. As shown by subsequent studies, all samples, when used, retained their physical properties and performance characteristics.

Currently, the contact fluid is being tested at temperatures below 70 ° C with ultrasonic inspection of the rail tracks.

The contact liquid of the proposed composition complies with sanitary standards and rules in accordance with GOST 12.1.007-076 and belongs to safety class IV (low hazardous substances).

Claims (2)

1. Contact fluid for ultrasonic inspection, containing monohydric primary alcohol of aliphatic series, technological additives and water, characterized in that it additionally contains ammonium acetate, and isopropyl alcohol as alcohol in the following ratio of components, wt. %: isopropyl alcohol 35-55; ammonium acetate 20-35; technological additives not more than 2.0 and water the rest. 2. Contact liquid for ultrasonic flaw detection according to claim. 1, characterized in that the technological additives contain: a corrosion inhibitor 0.5-1.0 wt. %; for chromaticity the pigment is 0.002-0.006 wt. %; for the smell of perfume 0.02-0.2 wt. %; surfactant 0.1-0.35 wt. %, which is mainly used as syntanol, neonol.