SU1680738A1 - Composition for preparation nielloed covering of metal - Google Patents

Description

one

(21) 4754703/05

(22) 10/27/89

(46) 09/30/91. Bksh. Number 36

(71) Novocherkassk Polytechnic Institute. Sergo Ordzhonikidze

(72) A.G.Tkachev, A.Ya. Kozrsky, V.A.Guziy, E. „F.Melnichenko,,, V.I.Labetsky, O.N.Tkacheva

and A.S. Kushnarev | (53) 667.637.4 (088.8) (56) Appen AoAo Temperature-resistant inorganic coatings. L .: Chemistry, 1976, with „259о

Abramovich B.G. and others. Intensification of heat exchange by radiation using coatings. M .: Energie, 1977, p. 255.

For Japan No. 57109868, class From 09 D 5/00, published 1982

(54) COMPOSITION FOR PREPARING THE BLACK COATING ON METAL (57) The invention relates to the metal-working industry, in particular to the coating of the heat-receiving surface of ferrous metal and alloy billets during process heating. The invention allows for self-peeling of the coatings after the technological heating thereof due to the use in the composition of the composition, wt%: refractory clay 2-5; carboxymethylcellulose technical 2-5;

 water else; 15-25 magnetite (FeOj-FeQ) as a black filler. 4 tab.

(L

The invention relates to metalworking in mechanical engineering and other fields, including the thermal heating of metals for various purposes, in particular for the coating of the heat-receiving surface of metal billets from ferrous metals and alloys during process heatings. It can also be used in the heat treatment of non-ferrous metal blanks,

The aim of the invention is to provide self-peeling of the coatings after technological heating.

The composition was prepared as follows.

Refractory clay and technical carboxymethyl cellulose are dissolved in water, magnetite is added and the mixture is stirred to a creamy state. Forms a homogeneous, stable, non-layering suspension.

The resulting suspension is applied to a metal blank, the surface of which, after the first test, is cleaned on a lathe until a metallic luster appears.

The coating lies in a layer of uniform thickness, does not crack after drying, and the metal does not shine through. The thickness of the coating is 0.1-0.15 mm.

i The billet with the applied and dried coating is placed in a laboratory tsepe of the type MP-24UM, preheated to 650 C and with the help of seconds 00

about

V4 GJ 00

domera measure the duration of its heating to 600 ° C with an interval of. The temperature is measured using a chromel-alumel thermocouple, the hot junction of which is placed in a twist along the axis of the workpiece (diameter 3 mm, depth 12 mm) and caulked with chamotte mass.

Table 1 presents examples illustrating the invention.

Characteristics of the compositions and the test results of the coatings are given in table 2-4.

Claims (1)

Invention Formula Composition to obtain black coatings on metal, including Blacking filler FeO-CraP, Fe Oj NiO  u feo Link Na O Si02 Clay refractory Carboxymethylcellulose The mixture is crumpled, poorly mixed, has a viscosity Forms stable suspension, does not stratify Also Also Mix after mixing has increased viscosity and nd. 1680738 instructor five carboxymethylcellulose and water, characterized in that, in order to ensure self-peeling of the coating after its technological heating, it contains, as a black filler, magnetite (FeQ) in the following ratio, wt.%: I Magnetite. (, FeQ) 1 5-25 Refractory Clay 2-5 Carboxymethylcellulose2-5 WaterEverything Table 1 90 20 3 25 5 thirty 7 61.2 16.6 Table 2 The coating is layered with a layer of uneven thickness, prone to slipping on vertical surfaces. After drying does not crack, the coating is laid with a layer of uniform thickness, the metal does not shine through. After drying, the same does not crack. The coating is covered with a layer of uniform thickness, but it is difficult to apply. When dried, the coating cracks and partially peels off. 6 Forms stable sus- (analog), zia, does not exfoliate. Mixture Ability to peel off Good Good good Do not self-detach Partially exfoliated (55-60%) The coating lies evenly, the metal does not shine through. No cracks are formed during drying. Table3 Table4 Metal surface characteristic after chipped coating The surface is clean, slightly oxidized. The same. The surface is slightly oxidized.