SU1458425A1 - Composition for chrome-titanium-plating of steel articles - Google Patents

Abstract

The invention relates to the chemical-heat treatment of steel products and can be used in mechanical engineering for the strengthening of steel products. The aim of the invention is to increase the bulk capacity of the composition. The composition contains, wt%: chromium oxide 52-56; titanium powder 16-20; cryolite 6-8; paraffin 4-6; ammonium ammonium 5-8; alumina - the rest. This allows a 1.2–1.4-fold increase in the saturation of the composition. 1 tab.

Description

one

The invention relates to metallurgy, in particular to the process of diffusion saturation of steel products with chromium and titanium in order to increase their corrosion resistance and wear resistance.

The purpose of the invention is to increase the saturability of the composition.

The composition containing chromium oxide, titanium powder, cryodite, para-Athens and alumina, additionally introduces ammonium tartrate in the following ratio of components, wt.%:

Chrome oxide

Titanium powder

Cryolite

Paraffin

Tartrate

ammonium

Aluminum oxide

52-56

16-20

6-8

4-6

5-8 Else

In the process of chromotitanation, the decomposition products, ammonium tartrate, react with the oxide layer, form ccts on the surface of the products, and dissolve it, thereby

increase the intensity of all products chromium and titanium.

In addition, the decomposition of ammonium tartaric acid produces atomic nitrogen, which also diffuses into the surface layers of the products and forms highly solid carbonitrides of chromium, titanium and other alloying elements, which positively affects the increase in the wear resistance of the products.

Purpose of the entered components

following.

Chromium oxide and titanium powder are introduced to produce atomic chromium and titanium, which diffuse into the surface layers of the products.

Cryolite and paraffin are activators.

Alumina is introduced into the mixture to prevent sintering of the particles of the mixture.

Ammonium tartrate is a colorless crystalline product with a monoclinic lattice and chemical forgula (W4) g -.

(L

SP

00 4

to cd

Not explosive, not flammable, does not finish. Its purpose in the mixture is to dissolve the oxide 1 st layer formed on the surface of the products and the image (# is atomic nitrogen.

The chromotitanation process is carried out as follows.

Products designed for chromotitanation are degreased with a fire (70-90 ° C) with a 5% alkaline solution and heated to 200-250 ° C to remove moisture. The cooled products are placed in containers with fusible closures and layer by layer perestayut mixture of the specified composition. As a sealant, soda glass is used.

Containers are loaded into an electric furnace, heated to 1000–1050 ° C and kept at this temperature of 2–20 h. The duration of exposure depends on the required thickness of the diffusion layer, which is a constructive parameter

After the end of chromotitanation, the containers are unloaded from the oven, cooled to room temperature and depressurized. And they cleaned them with a metal brush.

mixes. Together with chromatizing products, witness specimens made of the same steel grade as the products, which determine the thickness of the diffusion layer and the quality of chroma titanization (visually), are also exposed. Chromotitany products have a silver color.

Example. Samples made of 40ShMA steel were chromotitanated by the one you described.

Q 5

about 5

about

0

five

not in the formulations, the mass percentage of which is presented in the table. The chromotitanation temperature was 1000 ° C, and the exposure time was 6 hours. The test results are presented in the table.

As can be seen from the obtained data, the proposed composition for chromating has a saturating capacity of 26–38% higher than that known.

When chromotitanation in the composition containing the active components below the lower limit values, the thickness of the diffusion layer of the products increases slightly, and when chromotitanation in the composition with the content of active components above the upper limit values, the thickness of the diffusion layer practically does not increase,

Claims (1)

Invention Formula A composition for chromatising the steel products, including chromium oxide, titanium powder, cryolite, paraffin and a mixture of aluminum, which differs from and with the fact that, in order to increase its saturability, it also contains ammonium tartaric acid, wt.%: Chromium oxide. 52-56 Titanium powder 16-20 Cryolite6-8 Paraffin4-6 Tartrate ammonium5-8 Alumina Rest Chrome oxide Titanium powder Aluminum oxide Cryolite Paraffin (Protote Chrome oxide Titanium powder On the surface of products, the oxide layer Traces of the oxide layer is 5 3  4 Else 52 149 16 6 4 five Rest 54,158 18 7 five 7 Rest 56 170 20 eight . 6 eight Rest 57 174 21 3 7 9 The rest. her Table continuation No oxide layer Also  II No oxide layer