JPS61117286A - Steel parts having threaded part - Google Patents

Abstract

PURPOSE:To prevent the seizure of a threaded part when iron and steel parts having the threads are used at a high temp. by forming a coating layer consisting essentially of the powder of graphite and hydrous magnesium silicate- base clay ore on the threaded part. CONSTITUTION:The liquid prepd. by the powder of graphite such as colloidal graphite and 0.1-200mum powder of the hydrous magnesium silicate-base clay ore such as sepiolite, attapulgite, palygorskite, loughlinite, to a dispersion medium such a alcohol at 1/3-3pts.wt.: 1pt.wt. ratio and mixing the same is coated to the threaded part of the iron and steel products such as nuts and bolts formed with the thread on the inside surface or the outside peripheral part. Th coating layer of the above-mentioned compsn. is formed on the threaded part and the seizure owing to the formation of oxide, scale, etc., is obviated even if the above-mentioned pats are used at high temp.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a steel component having a threaded portion.

More specifically, the present invention relates to a steel component having a threaded portion that does not seize even if the W4 component is exposed to a high-temperature environment.

[Conventional technology and problems]

Generally, when a steel part with a threaded part is placed in a high-temperature environment, the threaded part of this steel part will seize up.
Even if an attempt is made to change or release the connection state of the threaded portion, a problem arises in that it cannot be easily removed.

The main causes of this problem are as follows. One of them is that oxidized scale is generated on the surface of the threaded portion of the steel component at high temperatures, and this scale acts as a stopper, causing problems. Another problem is that the core portion becomes crimped due to strong tightening caused by temperature differences or thermal expansion differences in the threaded portion at high temperatures. In the former case, one possible solution to these problems is to make the threaded portion of a material with excellent oxidation resistance, such as stainless steel. However, in this case, stainless steel is expensive. Even if these materials are used, they have the disadvantage that they cannot sufficiently prevent burn-in. In addition, in the latter case, it is better to lower the tightening force of the connecting part, but
The disadvantage is that thermal shock and vibration due to temperature fluctuations in the core cause loosening of the core, resulting in problems.

7. As a method for solving these conventional problems, it has been proposed to previously apply various surface treatments to the threaded portions of steel parts. One of them is a threaded part in which a threaded part made of stainless steel is coated with a coating material made of a silicone resin containing graphite (Japanese Patent Laid-Open No. 55-149412).

However, although this does provide a certain degree of anti-seizure effect in the case of a threaded part made of stainless steel, it cannot be said to be sufficient in the case of a threaded part made of carbon steel, which has poor oxidation resistance.

In view of the above-mentioned problems of the prior art, the inventors of the present invention made extensive studies to solve the problems and conducted various systematic experiments, resulting in the completion of the present invention.

1. Object of the Invention An object of the present invention is to provide a steel component having a threaded portion that does not seize even if placed in a high-temperature environment.

[Structure of the invention]

The steel component having a threaded portion according to the present invention is characterized in that a coating pipe whose main components are graphite and a hydrous magnesium silicate clay mineral is provided on the surface of the threaded portion.

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

The steel component in the present invention is a steel component having a threaded portion. The steel parts include a nut having an internal threaded part, a bolt having an external threaded part, and parts composed of both.

In addition, parts consisting of a female thread and a port provided on one part of a steel product, parts consisting of a male thread and a port provided on a part of a steel product, There are parts that are composed of a male threaded part provided on one part and a female threaded part provided on another part of the steel product.

The coating layer mainly contains graphite and a hydrous magnesium silicate clay mineral.

Here, the hydrated magnesium silicate clay mineral (hereinafter referred to as the clay mineral) is commonly known as mountain coltain 1e.
It is a clay mineral whose main component is hydrated magnesium silicate and has highly reactive hydroxyl groups on its surface. In addition, some of magnesium is aluminum, iron, and sodium.

1 for nickel etc. (It may have been replaced.

Specifically, Sepiolite, which is mainly composed of hydrated magnesium silicate, Attapulgite, which is mainly composed of hydrated magnesium aluminum silicate, and Palygorskite, Lough- sl 1nite) or meerschaum (Me ers =cha+nx), and one of these or a mixture of 2 or more pH is used.

The clay mineral may be used in the form of powder, granules, or plates, but it is preferable to crush it to the extent that the pores of the clay mineral remain, and the size thereof is 0.1 μm to 200 μm.
A value in the μm range is more preferred.

Furthermore, graphite is not particularly limited.

A finely powdered material such as colloidal graphite is preferred.

The steel part having a threaded part of the present invention is formed by providing a coating layer mainly composed of graphite and the clay mineral on the surface of the threaded part of the W44 part.

The amount of graphite contained in the coating MK is preferably 3 to 5 parts by weight per 1 part by weight of the clay mineral. This is because if the graphite content is less than 1 part and 3 parts by weight, there is a risk that effective lubricity of the threaded portion may not be obtained.

Moreover, if 3 parts by weight is added, the antioxidant effect of the clay mineral may be inhibited.

Further, the coating layer may be provided on either the surface of the male threaded portion or the female threaded portion of the threaded portion, but if it is provided on both of them, an excellent anti-seizure effect can be achieved. can.

Here, a typical manufacturing method of a steel part having a threaded portion according to the present invention is as follows. First, the clay mineral having a particle size of 1 degree is prepared.

A suspension of the clay mineral is obtained by adding it to a dispersion solvent such as water or Allure, and mixing and dispersing it. Next.

Graphite powder and appropriate additives are added to the suspension and mixed.
Disperse to obtain coating paint of uniform concentration.

Cocote # FIII is a household mixer, homomixer, Henschel mixer, ball mill, and vibration mill.

This is done using a disver mill or the like.

Next, the coating paint is applied to the surface of the threaded part of a steel component having a threaded part, and dried if necessary.

If the steel part is a part that has either a male thread or a female thread, such as a bolt or nut,
The paint can also be used as a steel part by drying it after application.
When the parts are ready for use, a core paint may be applied and the assembly may be allowed to dry. If the G4 part is composed of a steel product with a male thread and a steel product with a female thread, apply the paint to the surface of the thread of at least one of the steel products and dry it. Alternatively, the paint t-ff1 may be applied to the surface of the threaded portion of at least one W14i# product, assembled, and then dried. When drying is performed after assembly, it is preferable to use a paste-like paint with a reduced moisture content.

Here, the coating paint is applied by a brush coating method.

This can be done by methods such as the Nupre spray method or the dipping method.

Further, drying is conveniently carried out by leaving it at room temperature, but in order to shorten the drying time, it may be carried out by forced drying using a hot air blower or the like.

[Operations and Effects of the Invention] The steel component having a threaded portion of the present invention is a holding part component that is excellent in preventing the threaded portion from seizing at high temperatures. Therefore, even if the parts are placed in a high-temperature environment, the threaded portions will not seize, so that the connection state of the threaded portions can be easily changed or released.

In this way, there is provided a steel part having a threaded portion according to the present invention.

Although the mechanism by which such an effect is exerted is not yet completely clear, it is thought to be of the 9th order.

That is, 9. The coating layer provided on the surface of the threaded portion of the steel component of the present invention; 4. Graphite and the clay mineral solidify in a uniformly dispersed state, forming a dense coating layer on the surface of the thread.◎ When this coating layer is placed in a high temperature environment, the coating layer The clay mineral is uniformly dispersed and solidified.

At 550°C to 800°C, it loses its water of crystallization or hydroxyl groups and becomes semi-cephalic, but its morphology remains unchanged and becomes a dense inorganic film, which exhibits excellent antioxidant effects due to the presence of this film. . In addition, graphite promotes this anti-oxidation effect and its own lubricity prevents the coating layer from peeling off when the parts are assembled or the connection state is changed or released, so it has a synergistic effect. It is thought that the prevention of seizing of the threaded portion, which can occur at high temperatures, has been achieved.

Here, the reason why the coating layer is a dense coating layer in which graphite and the clay mineral are uniformly dispersed is as follows. In a coating composition composed of graphite, the clay mineral, and a dispersion solvent, the graphite and the clay mineral are maintained in a uniformly dispersed state due to the dispersibility and anti-sedimentation properties of the clay mineral. When this paint is applied to a threaded portion, it easily adheres like a general paint due to the adsorption ability of the clay mineral. After that, even when the moisture is removed by drying, the evenly dispersed graphite and the clay mineral solidify while maintaining their uniformity.

This seems to be because a coating layer is formed as a dense film on the surface of the threaded part.

〔Example〕

The present invention will be explained in detail below.

Example 1 First, 120 f of sepiophyte powder having a particle size of 200 mesh or less was added to water 11 and uniformly dispersed and mixed in a household mixer to obtain a suspension of the clay mineral.

Next, graphite powder in the amount shown in Table 1 was added to the liquid.

By mixing and dispersing, a coating material with a uniform concentration was obtained.

Next, the paint was applied to a low carbon steel rolling pot prepared in advance.
) and (M6X1) were coated on the threaded surface and left to dry at room temperature, and the bolt and nut were used as assembly test samples.

Next, this test sample was placed in an electric furnace and heated to 700℃ for 2 hours.
After heating and holding for 5 hours and 50 hours.

It was taken out, cooled, and removed to examine the degree of burn-in. The results are shown in the test result column of the table as "I" and "
Shown in ``Cao''. After heating and holding at 700°C for 50 hours, it was taken out, cooled, and removed using a penetrating liquid lubricant, and the degree of burn-in was examined and compared. The obtained results are shown in "l" in the test results column of the table.・For comparison, paint with only graphite as an fA additive (sample number 0)
1) and a paint containing only Seviolite (Sample No. 02), the same PoA/Nuts as above were subjected to the same treatment and a burn-in test was conducted.

Furthermore, a comparative test was also conducted on untreated bolts and nuts.

The obtained results are also shown in the table.

In the table, “○” in the test result column indicates “no burn-in” and “△
” is “slightly burned,” rXJ is “slightly burned,”
Unrecyclable J and rXXJ respectively represent "significant damage".

As is clear from the table, it can be seen that the steel parts according to the present invention have an excellent effect in preventing galling.

Example 2゜Example 1. A coating material prepared using the same method was applied to the threaded surface of a low carbon steel rolled bolt (M8Xt25), dried at room temperature, and assembled to form a test sample.

Next, this sample was placed in an electric furnace, heated and held at 700° C. for 70 hours, and then taken out and cooled.

I removed it and checked the degree of burnout.

Also, for comparison, the 9m additive is a paint with only graphite.

Comparative test samples were prepared in the same manner for one coated only with Sebiotite and one untreated K without any coating, and the burn-off test was conducted in the same manner.

As a result, none of the products according to the present invention suffered from burning and was easy to remove, but the products using the comparative paint suffered from burning and were in a state where they could not be reused. It was dairy. Furthermore, the untreated ones.

Significant damage had occurred.

Example 6 The amount of graphite added in Example 1 was 120 f on the threaded surface of a low carbon steel rolled bolt and oak (M8X1.25).
After applying the auxiliary paint 1 and assembling it, it was dried at room temperature and used as a test sample.

Next, this sample was placed in an electric furnace and heated to 120°C at 700°C.
After heating and holding for an hour, it was taken out, cooled, and removed to examine the degree of burn-in. As a result, no burn-in occurred and removal was easy.

For comparison, an untreated product was subjected to the same heat treatment and a burn-off test was conducted, but it was completely burned and could only be removed.

Claims (2)

[Claims] (1) A steel part having a threaded part, characterized in that the surface of the threaded part is provided with a coating layer mainly composed of graphite and a hydrous magnesium silicate clay mineral. (2) A steel component having a threaded portion according to claim (1), wherein the hydrated magnesium silicate clay mineral is sepiolite, attapulgite, palygorskite, or loglinite.