JPS59144512A - Method of suppressing generation of scale on steel material and method of improving stripping property - Google Patents

Abstract

PURPOSE:To suppress the generation of a scale when heating and improve stripping property of the scale by coating the mixture of specified proportion of specified metallic powder, its oxide, silicic acid anhydride, kaolin and a water glass on the surface of a carbon powder layer formed on the surface of a steel material. CONSTITUTION:The carbon powder (graphite etc.) and a binder (the water glass etc.) are mixed uniformly, and the surface of a steel material is coated with the mixture to thickness of above 2mg/cm<2>. The surface of this coated layer is covered with the mixture composed of 10-50 weight parts metallic powder selected from Al, Cr, Ti, Mn, Cu, Ni, Co, Mg, Fe, 50-30 weight parts of the oxide powder of the above described metals 10-100 weight parts silicic acid anhydride, powder of refractory of kaolin, montmorillonite, dolomite group, 20-80 weight parts of the water glass, proper quantity of water to the thickness of above 5mg/cm<2>. The generation of the scales is suppressed when heating the steel material, and the stripping property of the scales can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for suppressing the formation of scale when heating steel materials and improving the removability of the generated scale.

(Technical background) During hot working, wood is usually heated in a heating furnace for 100 to 1
After being heated to 300°C2, it is transferred to a processing machine. At this time, the surface of the steel material is oxidized and so-called scale is generated due to contact with the atmosphere surrounding the n-anium in the heating furnace and the atmosphere during transportation. The generation of school leads to the loss of steel materials,
Also, if this gets caught between the steel material and the tool during machining,
This can damage the tools, and the scale can move in and out of the steel, causing surface scratches and degrading the quality of the product.

(Prior Art) Various methods have been used to suppress the school's production schedule. The most common method is to apply so-called scale inhibitors before heating the preparation. For example, Japanese Patent Publication No. 53-43124 discloses applying a composition consisting of chromium oxide and other materials to steel materials for the purpose of inhibiting scale formation. Various metal- or non-metallic mixtures are known as scale inhibitors. However, with conventional methods, not only is scale suppression insufficient, but even after applying a scale inhibitor, the generated scale and scale inhibitor adhere strongly to the steel material, resulting in a scale breaker being removed before processing. Even if you try to remove it, it will not be removed completely and the above problem will occur.

Given the current situation above, scale generation should be sufficiently suppressed.
There is a strong need for a method for treating steel materials that allows for easy removal of scale even if a small amount of scale occurs.

(Objectives of the Invention) An object of the present invention is to provide an improved steel processing method that suppresses the formation of scale 7 and improves the removability of the generated scale 6 .

(Structure of the Invention) The present invention covers the surface of steel with two coatings M each having a different composition.
It is characterized by being coated with.

That is, in the present invention, the surface of a steel material is coated with a composition containing a binder and carbon powder, and then the composition layer surface is coated with (a) aluminum, chromium, titanium, manganese, copper, nickel, cobalt, magnesium, and iron. 10 to 50 parts by volume of metal powder selected from (r:i)
5 to 60 parts by weight of the metal oxide powder described in (a) above, (c) 10 to 1 liters of silicic anhydride, I LJ
Og Okibe, (4 Kaolin, montmorillonite, dolomite refractory powder 10 to 100.*=
parts, (force) water glass 20 to 80 parts by weight, (g) water drops
This is a method for improving the formation of scale during heating of steel materials and the removability of the generated scale, which is characterized by using a composition containing oxidation.

The components of the present invention will be explained in detail below.

(Bottom) Composition) In the present invention, as the carbon powder, one or more of graphite, carpump thick, charcoal powder, etc. can be used, and as the binder for the carbon powder, water glass or highly water-soluble Molecular substances can be used. As water bathing polymeric substances, derivatives of natural polymeric substances such as carboxymethylcellulose and synthetic molecular substances such as polyacrylic acid can be widely used.

After uniformly mixing the carbon powder and the caking agent, if necessary, add 51N of water to adjust the consistency to make it easier to apply the composition.At this time, the ratio of the carbon powder to the caking agent is It is desirable that the carbon powder is greater than the binder in terms of weight ratio.

The carbon powder-containing composition prepared in this manner will be referred to as a lower layer composition in the following description.

(Metal Powder and Metal Oxide Powder) In the present invention, aluminum, chromium, and titanium are particularly desirable among the components (a), and particularly desirable among the components (b) are aluminum Ii! 4
arsenic, chromium oxide and titanium oxide. This is because the use of these wire meshes and metal oxides has a particularly strong effect of suppressing scale formation.

(Top layer composition) In order to produce a composition containing the substances (a) or (g) above (hereinafter referred to as the top layer composition), the substances (a) or (g) must be uniformly mixed. Water is then added to adjust the consistency as necessary to facilitate application to the copper phase.

(Coating amount) In the present invention, the coating amount of the lower layer and upper layer compositions to be applied to the steel surface is expressed as dry weight, and one layer is 2 rq.
/ crot or more, upper j @ is preferably 5 tny / 6M or more [7. The reason is shown in Figures 2 and 6.
As shown in the figure, if the coating amount of the lower layer is less than 2 ml/cd, the scale releasability will be poor, and if the coating amount of the upper layer is less than 5 ml/cr/1, the scale generation suppression effect will be poor. It is from.

The coating amount is preferably 5η/C or more, and the upper layer is 5η/C- or more.
MIF/cr1 or more, preferably 20η/crA
That's all.

(Actions and Effects of the Invention) The effects of the present invention are such that a composition containing the substances of the lower layer composition and the upper layer composition [(a) to g) above is referred to as an upper layer composition. , ] is expressed by two coating layers formed from.

A composition is prepared by completely mixing the carbon powder and the upper layer composition,
When this is applied to the surface of a steel material to form a single coating layer, the scale inhibiting effect is poor, and furthermore, it is difficult to remove the generated scale and the fixed scale inhibitor.

When applying the upper layer composition i in the present invention is omitted,
If the order of applying the lower layer composition and the upper layer composition is reversed, no effect will be produced because the carbon powder will easily oxidize and disappear during heating.

Even if the application of the lower layer composition of the present invention is omitted and the steel material is coated with only the lower layer composition, the effect of blocking the atmosphere and suppressing scale can be obtained to some extent, but it is not sufficient, and it is difficult to remove the generated scale. is difficult. Moreover, this upper layer composition itself is sintered in the heating furnace to form a strong bonding layer on the surface of the steel material.

This fixed layer is difficult to remove and remains even when a scale breaker is used, causing damage to tools and steel materials. l! By doing so, it is possible to suppress the generation of scale to an extremely small amount, thereby increasing the yield of steel materials and conserving resources. Moreover, if steel materials are treated by the method of the present invention...
The scale, including the treatment agent, has good removability and can be easily removed using a scale breaker, for example, so there is no damage to tools or surface scratches on the steel material during hot working.

In the method of the present invention, the effects of the two layers that wrinkle the steel surface are estimated as follows.

First, the composition of the upper layer temporarily prevents oxygen from reaching the surface of the steel material from the atmosphere through its reducing action and desired shielding effect. Next, ``the layered paraboloid is a relatively low amount J'' that could not be prevented by the upper layer composition, and finally reaches the steel surface by the reducing action of carbon and the physical shielding effect of the layer. prevent the occurrence of scale. In addition, the presence of the lower layer suppresses the adhesion of the upper layer composition to the steel material,
Facilitates peeling off of scale enriched with the underlying composition.

(Example) Next, the present invention will be specifically explained with reference to Example 4b.

However, the present invention is not limited to these in any way.

(Processing method) In each of the following examples, pre-weighed steel tji
'i (8PCC, 80 x 60 x 1.2 mm)
was used as a test piece, and the lower layer composition was kneaded well on both sides and applied uniformly with a brush, dried at 110 ° C. for 60 minutes, then weighed, and the applied amount of the lower layer composition was determined as a dry coating of 45M. Ta. Next, on the coating layer of the lower layer composition, the upper layer composition was thoroughly kneaded and applied with a brush, and the coating amount of the upper layer composition was determined in the same manner as for the lower layer composition. In this way, the steel plate specimen coated with the two layers of scale inhibitor was heated to 1200°C.
After heating in an electric furnace in an air atmosphere for 1 hour, the samples were drained and evaluated for scale suppression effect and scale removability improvement effect using the following method.

(Evaluation method 9 of scale suppression effect and scale removability)
Figure 1 is a perspective view of the main parts of the test equipment.
The mark indicates the direction of movement of the specimen.

The steel plate specimen (1) is moved horizontally in the longitudinal direction and passed through a total of four nozzles (2), two nozzles (2) on the top and two on the top, arranged as shown in Figure 1. was sprayed to remove scale and scale inhibitor, dried at 110°C for 60 seconds, and weighed l~. The amount of M at that time was defined as Wl.

The operating conditions of the test equipment are as follows: ○Discharge pressure (
each nozzle) 106 Kg/cnl nozzle diameter
1.7IMlω discharge amount
Question 171-7 Distance between nozzle and test piece 50
Ran Distance between nozzles arranged in parallel 60 Moving speed of barrel test piece 2 Scale and scale inhibitor remaining after the above treatment are completely removed by applying mechanical impact,
Weighed. M Tsukuda at that time was designated as W2. The weight of the steel plate specimen before applying the scale inhibitor is W. After binding, the oxidation weight loss and scale removal rate were determined using the following equations.

Oxidation area! Rate-((WOW7)/WO)X I 00
% scale removal rate -C(WO-W+)/(WO-W2
．． ) ) 'worth it.'

Example 1 As a lower layer composition, 161 g of graphite, 6 parts of water glass, and 60 parts by weight of water were mixed and kneaded well, and the mixture was uniformly applied to both sides of a steel plate test piece. After finding the M fabric amount using the above method,
60 parts by weight of aluminum powder, 22 parts by weight of aluminum oxide powder, 55 parts by weight of anhydrous silicic acid, 55 parts by weight of kaolin, 50 parts by weight of water glass, and 15 parts by weight of water were mixed on the coated layer. The upper layer composition prepared by thoroughly kneading was applied [-1] The amount of application was determined by the method described above. The coating amount is 20ml/e for the lower layer.
L'ns, the upper layer was 80 Li/Ca. Next, the oxidation loss rate and scale removal rate were determined according to the above-mentioned order.

The results are not shown in Table 1 below.2, Example 2 The coating amount of the lower layer composition in Example 1 was changed to 10〃mi/
crl, and otherwise treated in exactly the same manner as in Example 1, and the test was conducted. The results are shown in Table-2.

Example 6 Both the lower layer composition and upper layer composition of Example 1 were mixed at 20%
Comparative Example 1 The upper layer composition of Example 1 was applied directly without applying the lower layer composition of Example 1. was applied to the test piece. Its σ/cloth amount is 100■/C
It was the shoulder. The rest was treated and tested in the same manner as in Example 1.

The results are shown in Table-1.

Comparative Example 2 Only the lower layer composition of Example 1 was applied, but no lower layer composition was applied. The coating amount was 80 l/Ca. The rest was treated and tested in the same manner as in Example 1. The results are shown in Table-1.

Comparative Example 6 16 parts by weight of graphite, 60 parts by weight of aluminum powder, 22 parts by weight of aluminum oxide powder, 55 parts by weight of silicic anhydride, 56 parts by weight of water glass, and 45 parts by weight of water were mixed and coated. The coating amount was 100 μ/cd.

The rest was treated and tested in the same manner as in Example 1. Display the results -
1.

Table 1 As shown in the above examples, when steel materials are treated by the method of the present invention, the oxidation loss rate is small and the scale removal rate is large. This shows that when steel is treated by the method of the present invention, it is possible to suppress the occurrence of scale on the steel and improve the peelability of the generated scale and the scale remover.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a test apparatus used for evaluation tests of scale suppression effect and scale removability. FIG. 2 is a graph showing the oxidation reduction rate according to Example 1. FIG. 5 is a graph showing the scale removal rate according to Example 1. 1...Test piece 2...Nozzle procedure amendment document Showa l] March 15, 1959 Mr. Kazuo Wakasugi, Commissioner of the Japan Patent Office 1. Indication of the case 1982 Patent Application No. 018047 2. Name of the invention Steel scale Method for suppressing the formation of and improving peelability 3, and its relationship to the case of the person making the amendment Patent applicant name: Yushiro Chemical Industry Co., Ltd. 4th Director Address: Ono Building, 1-21-11 Yotsuchobashi, Minato-ku, Tokyo 5 Date of amendment order Voluntary amendment 6 Number of inventions increased by amendment 0 7. Column 8 for detailed explanation of the invention in the specification subject to amendment, Contents of amendment (1) Page 5, line 10 of the specification "Caking" is "caking agent"
and correct it. (2) Correct the "coating amount" in the third line from the bottom of page 6 of the circular to "lower layer coating amount." (3) "30 seconds" on page 10, line 8 of the same book is replaced with "
30 minutes”.

Claims (1)

[Claims] A composition containing a binder and urea powder is applied to the surface of Takuri, and then the surface of the composition layer is coated with (a) aluminum, chromium, titanium, manganese, *L2:"' le,
Powder of metal selected from cobalt, magnesium and iron 10 to 50 diodes, population) above (a) Vcj
J[: Powder of metal oxide 5 or 3DfJ
j sieboiling, (/1 anhydrous silicon m 1o and 10, Og
(Okibe, ni) Kaolin, montmorillonite, dolomite type powder 1 fire powder 10 or to o
z, z part, ni) water glass 20 l so
x,! M, (g) water
With m paraboloid containing Jψ, p
A method for completely improving the generation of scale during heating of steel material and the peeling property of scale.