JPS5919152B2 - Thermal metal article marking composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a marking composition for hot metal articles, especially articles of iron or steel.

A common method for marking hot metal articles is to hand write on the article using a chalk needle or waxy crayon that melts at high temperatures and leaves a permanent mark.

Marking thermal articles in this manner is not satisfactory. This is because the person marking the articles comes very close to the articles and is therefore exposed to particularly high temperatures and health risks, which can lead to fatigue, carelessness and incorrect marking. Since the work is monotonous, the risk of mistakes increases. Without the mark, the ingot, bloom or slab cannot be identified, requiring reclassification, which results in economically significant losses. Also, labor costs are high using this method. Japanese Patent Application No. 8019/1989 proposes the use of ceramic materials for marking hot steel, suggesting that this material be sprayed onto the surface, and more specifically using an aqueous solution of ZnsO4 (Example 1) and A slip containing sodium silicate, boric acid, anhydrous chromium oxide and 49% water (Example 1) is described.

The use of powders is mentioned in passing. The scouring of the material appears to be aimed at producing a vitreous layer, which in fact tends to break down during subsequent rolling of the steel in a mill. The use of damp substances is also disadvantageous. This is because the water vapor produced when in contact with hot metals removes large amounts of useful substances. U.S. Pat. No. 3,296,689 discloses the use of aluminum paint for marking metals, and more specifically, the application of a paint containing 20% aluminum flakes in a resin varnish with a brush. Suggests.

Spraying has also been suggested as an alternative method. The purpose of this aluminum is to provide detectable low temperature distinct color zones on red hot steel articles. The purpose of the present invention is to
The object of the present invention is to provide a marking material for hot metals, especially steels, which adheres reliably and strongly enough to survive subsequent processing.

Another object of the invention is to provide a marking material suitable for use in a manner that allows the operator to be positioned at a sufficient distance from the article for safety.

Yet another object of the invention is to provide a marking material that suffers little from wear and can be applied by simple equipment that requires little maintenance.

According to the invention, it is applied in powder form to a hot metal surface. - Dry powder suitable for tinting and as a pigment TiO2
, consists of three components: aluminum and SiO2 or bentonite as a binder, the aluminum is effective to act as a reducing agent and reduce oxides on the hot metal surface, and the adhesive 4 is above 200℃ A marking composition for a hot metal article is provided that is effective for forming a bond on a hot metal surface at a temperature of .

The material chosen should be resistant to the surface temperatures to which it is applied.

For the binder to be effective, the temperature of the metal can be well above 200°C, for example 1200°C. In the case of iron or steel surfaces, the aluminum powder serves to reduce the primary rolling oxide of the iron;
This prevents or minimizes subsequent mark peeling due to underlying rust. It is particularly important that the composition be dry when applied.

It is desirable that the carrier gas used to spray the composition onto the metal surface be very dry, and if compressed air is used, the air should be prepared to be dry and free of dust. Requirements that can be set for marking powders are that they are not toxic and that they must not contain volatile substances in major amounts.

Requirements that can be placed on the mark obtained are that the mark should have good contrast and visibility both when the article is hot and when it is cold, and that the mark should not peel off during or after rolling. The mark must not contain compounds that adversely affect the steel, must be resistant to temperature in subsequent thermal post-treatments, and must not fade during storage or transport in open air. These requirements can be met by materials embodying the invention. Preferably, the aluminum powder is the marking material 50
It is present in an amount greater than % by weight and preferably has a maximum particle size of 600 microns or less.

One suitable binder is silicic anhydride (SiO2) in powder form.
). Most preferred, however, are bentonites in dry form with a low magnesium content, for example less than 5 (F6). It can also be used for marking iron, such as hot iron molds (coquille) and cast plates, without the need for, and with equally good results.A preferred embodiment of the method of use of the composition of the invention is illustrated by way of example in the accompanying drawings. do.

This drawing is a diagram of a conventional spray gun modified to carry out this method. Explaining the drawings:
A hot steel ingot 1 to be marked is shown diagrammatically, moving under the injection nozzle 2 of a dry spray gun 3, and a carrier gas dinit 4 carrying dry marking powder onto the hot ingot 1 is injected. Nozzle 2
get out of

This hand-operated spray gun 3 is of a common type, an example of which is manufactured by The DeVillbis Company of Toledo, Ohio, USA.
Company's CB-type flock gun and Atlas Copco Tools (AtlasCOpcOTOOls)
) ABOEccO4O type gun.

The cancer itself requires no protection. This gun was modified by providing a long discharge tube 5. This discharge pipe 5
extends from the mixing vessel 6 to the nozzle 2. A suitable nozzle is 3m71L. Compressed air, which is prepared in a dust-free and dry state, is supplied from the hose 7 to the hole 9 in the handle 10 of the gun 3. This hose 7 is connected to a nipple 8. The trigger lever 11 is connected to the main operating valve 1 in the hole 9.
Operate 2. Needle valve 13 regulates the air pressure. Typically, the pressure in the hose may be 6 atmospheres and is reduced by valve 13 to 0.2 to 1 atmosphere. The handle 10 is fixed to the cap 14 of the container 6 and the hole 9 is extended into the container 6 by a tube 15 with an eccentric end.

The air exiting the tube 15 thus creates a swirl, which swirls around the marking powder 16 contained within the container. The powder is thus entrained in the air stream passing through the cap 14 and through the discharge tube 5. A highly constant concentration of powder in the air dinitrate can be achieved in this way. The length of the extended discharge conduit 5 is approximately 2.5 m in this embodiment, so that the operator's hand can be at that distance from the hot metal surface.

The nozzle is preferably about 5Cr1L from the hot surface. EXAMPLES Some preferred marking compositions embodying the invention are described in the following examples.

Each of the powders was applied to a steel surface at a temperature of 1200° C. by a normal hand-held powder sprayer with a length of discharge tube as shown so that the operator's hand was at least 250 CfL from the metal surface. .

Compressed air was supplied at 6 atmospheres and was reduced to 0.2-1 atmospheres before entering the container containing the powder. The gun nozzle was moved approximately 5 CTIL from the hot surface. In each case satisfactory marking was achieved. The marks bonded immediately and showed high resistance to subsequent processing of the steel.

[Brief explanation of the drawing]

The accompanying drawing is a diagram of a conventional spray gun modified to be suitable for use with the composition of the invention. 1... Heat ingot, 2... Injection nozzle, 3... Dry spray gun, 4...
Carrier gas dinit, 5...Discharge pipe, 6
...Mixing container, 7...Hose, 8...
...Nipple, 9...Hole, 10...
・Handle, 11...Trigger lever, 12.
...Main operating valve, 13...Needle valve, 1
4... Cap, 15... Tube, 16.
...Marking powder.

Claims (1)

Claims: 1. A dry powder suitable for application in powder form to hot metal surfaces, comprising 3 of TiO_2 as pigment, aluminum and SiO_2 or bentonite as binder.
Aluminum is effective in acting as a reducing agent to reduce oxides on hot metal surfaces, and a binder forms bonds on hot metal surfaces at temperatures above 200°C. 1. A marking composition for a thermal metal article, the composition being effective for marking a thermal metal article. 2. A composition according to claim 1, wherein aluminum constitutes more than 50% by weight of the composition. 3. The composition according to claim 1, wherein the maximum particle size of aluminum is 600 microns or less. 4. The composition according to any one of claims 1 to 3, wherein the binder has a maximum particle size of 75 microns or less. 5 The weight ratio of TiO_2, Al and SiO_2 is approximately 4
:16:5. 6 The particle size of TiO_2 is 3-5 microns, the maximum particle size of Al is 600 microns or less, and the SiO_2
6. The composition of claim 5, wherein the maximum particle size of the particles is 40 microns or less. 7 The weight ratio of TiO_2, Al and bentonite is 2
:8:5. 8. The composition of claim 7, wherein the particle size of TiO_2 is 3 to 5 microns, the maximum particle size of Al is 600 microns or less, and the maximum particle size of bentonite is 75 microns or less.