SU831858A1 - Lining for chrome-plating of steel parts - Google Patents

Description

I

This invention relates to chemical heat treatment and can be used as a basic medium for diffusion chromium plating of steel products.

Known composition for chromium plating of steel parts, containing components, wt.%:

Chromium oxide30-45

 Aluminum powder 10-20 Aluminum oxide 14-24. Ammonium chloride 3-6 Mixture of acetone with glue based on phenol-formaldegnd resins modified with polyvinyl butyram19-25

This composition is intended for diffusion saturation at 10001100 ° C for 3-5 hours {lJ.

However, to increase the speed of the process, diffusion saturation must be obtained with a short-term temperature effect, which can be done with a pulsed laser. Included in this composition, chromium oxide cannot serve as a source of active atoms, since, its aluminothermic reduction cannot occur during brief impulses. Moreover, the constituent bond (acetone / glue mixture based on polyvinyl butyral modified phenol formaldehyde resins) is rarely used in industry, requires special preparation and is not sufficiently stable under the action of laser radiation.

Also known is the composition 2 for 2 (j chromium plating of steel parts, containing components, in mass%,:

Chromium carbides45-65

Iron dross 25-50 ammonium chloride 3-10

However, the components included in this composition provide diffusion saturation at 800-1100 s for long exposures and do not allow the chromium plating process under short-term pulsed temperature effects, since an increased amount of iron oxides in the composition reduces the proportion of the chromium-containing component (carbonic carbide) and the presence of an ammonium chloride activator leads to the formation of a significant amount of the gas phase, which in the short-term pulsed mode makes it impossible to form chromium atoms aktivnm

The purpose of the invention is to provide diffusion saturation of steel products under high temperature impulse effect, which is carried out with the help of laser radiation.

The goal is achieved by the fact that the composition containing chromium carbides, additionally contains liquid glass in the following ratio of components, wt.%:

Chromium carbides. 70-90 Liquid glass 10-30 A mixture of chromium carbides and liquid glass is applied to the steel surface to be treated with a thin layer of 0.3-1.5 mm thick. Under the action of laser radiation on the surface coated with n1) by the composition, the formation of chromium carbides from active chromium atoms, diffusing into the steel surface.

The use of liquid glass as a binder allows the coating to hold well on the surface of the product and contributes to its increased stability under the action of laser radiation.

An example. Diffusion chromium plating of samples from iron under the influence of laser radiation is carried out, and the samples are uniformly coated with a coating of 0.3-1.5 mm thick. The coating is prepared by mixing the powdered component (chromium carbides with a fraction size of 0.1-0.15 mm) with liquid glass | specific weight 1,2

Samples are subject to laser

radiation, while the power density of the laser radiation is CJ, 5-10 W / cm, the duration of the laser pulse / C - 1 ms.

Metallographic research

show that the thickness of the diffusion layer is 50-60 microns with a microhardness of 900-1100 kgf / mm. Spectral analysis established the chromium content in the diffusion layer

5 -2.5%. The results of diffusion saturation of samples from Armco iron If the pulse duration is L / 1 ms, the power density

2

q, 5 "10 W / cm

presented in the table.

Suggested Results Measurements of the thickness of diffusion layers obtained under the influence of laser radiation indicate a high saturating 55 ". abilities of the proposed composition. The diffusion layer consists of a solid solution of chromium in the c - iron. The use of the proposed composition for hydrogens, in comparison with known compositions, provides the possibility of diffusion saturation of steel products under the influence of laser radiation. of the invention Formulation Chrome plating for steel products containing chrome cadbides, which in order to ensure diffusion saturation of products under high-temperature pulsed laser radiation, it additionally contains liquid glass at the next (after the ratio of components, chromium carbides 70-90 Liquid glass10-30 Sources of information taken into account during the examination 1. USSR author's certificate No. 585235 class C. 23 C 9/02, 1978. 2. USSR author's certificate of application No. 268: 789 / 22-02, law C 23 C

Claims (1)

Claim A coating for chromium plating of steel products containing chromium carbides, characterized in that, in order to ensure diffusion saturation of the products at high 6 temperature pulsed exposure to laser radiation, it additionally · but contains liquid glass in the following ratio of components, 5 wt.%: Chromium Carbides 70-90 Liquid glass 10-30