SU1104377A1 - Reagent for revealing boundary between stainless and carbon steels and alloys - Google Patents

Abstract

REACTIVE FOR DETECTING THE BOUNDARY BETWEEN STAINLESS AND CARBON STEELS AND ALLOYS, containing sulfuric acid, copper sulphate and urotropine, characterized in that, in order to increase the stability and clarity of the contour of the visible boundaries, it also contains potassium permanganate, which is contained in the table, which contains blender. . / o: Sulfuric acid (J 1,82-1,83, 9-1,0 Sulfuric acid copper 5-15 Urotropin1,5-2,0 Potassium permanganate 0.15-0.20 Water Remaining.

Description

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This invention relates to the control of bimetals from stainless and carbon steels and alloys, in particular to reagents designed to detect the boundary between stainless and carbon steels.

A known reagent 1 for detecting the boundary of bimetals from alloyed and carbon steels, containing May. %:

Sulfuric acid14

Copper sulfate12

Water the rest.

This reagent can be used, if necessary, to identify clear boundaries between carbon and stainless steel and alloys, since an electrochemical reaction takes place on the metal surface when in contact with the solution, resulting in a copper layer deposited on the carbon steel, and copper does not precipitate on stainless steel. going on. Thus, a clear boundary appears between dissimilar materials. But after 10–20 min, the copper layer is covered with white bloom of the main copper salts, the boundaries between the materials blur, become fuzzy. This happens because precipitated copper is very active, atmospheric corrosion occurs on its surface, and basic salts of white copper are formed.

Thus, clear boundaries between dissimilar materials are unstable in time.

In addition, a high percentage of sulfuric acid requires the use of precautions when working with this solution.

Closest to the offer is reagent 2, containing May. %:

Sulfuric acid2-4

Copper sulfate 1,5-2,5

Organic Supplement

Condensation products

urotropine with aniline

in the presence of melamick

and benzyl chloride 0.05-0.15

Water the rest.

A disadvantage of the known reagent is that the chlorides, which are contained in the organic additive in the form of hydrogen chloride benzylaniline, activate the surface of the stainless alloy. The boundaries between dissimilar materials are not sufficiently clear and their resistance is short-lived, i.e., the time of preservation of the originally obtained sharpness of the boundaries is small and the boundary line quickly spreads

The aim of the invention is to increase the durability and clarity of the contour of the detected boundaries.

To achieve this goal, potassium permanganate was added to the reagent containing sulfuric acid, copper sulfate and urotropine at the following ratio of components, May. /about:

Sulfuric acid

(j 1.82-1.83 g / cm) 0.9-1.0

Sulfate copper5-15

Urotropin1,5-0,2

Potassium permanganate 0.15-0.2

Water the rest.

The addition of 0.15–0.20% to potassium permanganate solution increases the overall performance of the results and makes them stable. Potassium permanganate, a strong oxidizing agent, inhibits the anodic and cathodic processes on the surface of carbon steel, the copper layer increases more slowly, its quality is higher. The contours of the boundaries become clearer and remain as such for 2-3 days or more. Urotropin in the amount of 1, provides stability and clarity of the contour of the detected boundaries.

To test the proposed reagent, compositions were prepared, the composition of which is given in Table. one.

To prepare the reagent, the required amount of distilled water is poured into the flask, then a sample of copper sulphate is added, the copper salt is transferred to complete dissolution, then the required amount of sulfuric acid, hexamine, potassium permanganate is added and carefully transferred as each component is added.

The process of applying the solution to the test surface is carried out at room temperature. The solution is applied with a brush, cotton swab, dipping in a solution, spraying, etc.

The boundaries between the materials appear practically during the application of the solution.

Example. Shell of bimetal 12ХМ + -f08X13 with a thickness of 40 mm. The state of the edges - after gouging on the edge-cutting machine, without stripping and degreasing. Before welding, it is necessary to determine whether the layer of the cladding layer has been completely removed at the junction of the shell. The reagent is applied with a cotton swab, and the test results are summarized in table. 2

5 As can be seen from the data table. 2, the durability and sharpness of the bimetal boundary retention time is 58 hours or more.

The invention can be used in the repair of bimetallic apparatuses, arc arc gouging and the correction of defects in welded joints of two-layer steels and dissimilar steels, when it becomes necessary to identify clear boundaries between carbon and alloyed steels.

Table 1

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Claims (1)

REAGENT FOR DETERMINING THE BORDER BETWEEN STAINLESS AND CARBON STEELS AND ALLOYS, containing sulfuric acid, copper sulfate and urotropin, characterized in that, in order to increase the stability and clarity of the contour of the detected boundaries, it additionally contains potassium permanganate in the following ratio. %: Sulfuric acid (j = 1.82-1.83 g / cm ³ 0.9-1.0 Sulfur Copper 5-15 Urotropin 1.5-2.0 Potassium permanganate 0.15-0.20 Water Rest