JPH11111124A - Gas breaker built-in part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance rust preventive capability and enable prevention of deterioration in the electrical performance in oxygen-free environment by performing film formation treatment on the surface of a steel part exposed to an insulation gas. SOLUTION: An iron phosphate film formation treatment is applied to a steel part to be incorporated in the breaker. In that case, three processes, i.e., pre-treatment process, iron phosphate film formation treatment process and post-treatment process are provided. In the pre-treatment process, first, an organic solvent or alkali solution or the like is used to perform fat removal for removing oily stains on the steel part surface, and thereafter, dirt rust, and scale or the like on the steel part surface are physically removed. Next, in the iron phosphate chemical conversion treatment process, by immersing the steel part in the iron phosphate treatment liquid for about 5 minutes, the steel part and the iron phosphate chemically bonded with each other, a stable inorganic coating is formed, and this coating restrains generation of rust on the metal surface. The generated coating is insoluble, a poor electric bod conductor, and inhibits corrosion due to a local battery action. In the post-treatment process, washing with water, drying and the like is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a component of a gas switch, and more particularly, to a surface treatment of a steel component incorporated in a gas switch.

[0002]

2. Description of the Related Art Conventionally, steel parts incorporated in a gas switch have been subjected to electrogalvanizing so as not to generate rust during the storage period before being incorporated in the gas switch. Although the steel part itself may be made of stainless steel, it is expensive, and is galvanized at a low part cost.

[0003]

However, when the conventional steel parts are galvanized, zinc metal grows in a needle-like manner in a high-temperature state in oxygen-free (sulfur hexafluoride) and whiskers are formed. Generated. Whiskers are single-crystal metal fiber growths that resemble the shape of a cat's beard. The whisker may shorten the electrical insulation distance in the switching section or the like inside the gas switch, or may be detached and adhere to the insulating section to cause a short circuit, which may lower the electrical performance. Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a built-in component for a gas switch which has a high rust prevention ability and can prevent a decrease in electrical performance in oxygen-free condition. Is to provide.

[0005]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a steel part exposed to an insulating gas, wherein the surface treatment is a chemical conversion treatment.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Iron and steel components incorporated inside the gas switch are subjected to an iron phosphate conversion coating treatment. The iron phosphate conversion coating treatment is roughly divided into three steps: a pretreatment step, an iron phosphate conversion treatment step, and a post-treatment step.

In the pretreatment step, first, degreasing is performed to remove oily stains on the surface of the steel component using an organic solvent or an alkaline solution. Thereafter, dirt, rust, scale, etc. on the surface of the steel part are physically removed. In the iron phosphate treatment step, the steel component is immersed in the iron phosphate treatment solution for about 5 minutes. Then
The steel component and iron phosphate are chemically bonded to form a stable inorganic film, which suppresses the generation of rust on the metal surface. The resulting film is insoluble and a poor conductor of electricity, and has a rust-preventing effect in order to prevent the propagation of corrosion of iron due to local battery action. That is, the surface of a steel part that is easily rusted is converted into a state that is hardly rusted by the iron phosphate conversion coating treatment. In the post-treatment process, water washing, hot water washing, drying,
Perform buffing and the like.

As shown in FIG. 1, a heat cycle test and a parts storage standing test were conducted to verify the rust prevention effect of the iron phosphate treatment. In addition, a load switching test (8) was conducted to verify the state change of steel parts in sulfur hexafluoride gas.
00 times). As shown in FIG. 2, five types of test pieces 1 to 5 shown below were prepared as test pieces for each test.
L-shaped steel 1 of SPHC material treated with MZnC5, L-shaped steel 2 of SPCC material treated with iron phosphate conversion coating, welded L-shaped steel 3 of SPCC material treated with iron phosphate conversion coating, degreasing only The L-shaped steel 4 of the SPCC material that was performed, the S that only performed degreasing
There are five types of welded L-shaped steel 5 made of PCC material.

The iron phosphate chemical conversion coating solution used was Coolfoss manufactured by Dacro Shamrock Co., Ltd., and the amount of the phosphate chemical conversion coating was 700 mg / m 2. The test pieces 3 and 5, which are test pieces having a welded portion, were used with the scale attached, and were not pickled. As for the test piece 3 and the test piece 5, the side opposite to the welded portion is the front side, and the welded side is the back side. Test piece 1, Test piece 2 and Test piece 4
As for, the opposite side of the L-shaped bend is the front side, and the L-shaped bend side is the back side.

Next, a heat cycle test will be described. The test conditions of the heat cycle test were set at 20 ° C., 12 hours and 40 ° C. for 12 hours in a constant temperature chamber to make one cycle per day.
Repeated for days. During the test, water was filled in the constant temperature chamber to keep the humidity at 50 to 80%.

As shown in FIG. 3, as a result of the measurement of the corrosion weight loss in the heat cycle test, the test piece 2 subjected to the iron phosphate conversion coating treatment is at least five times as large as the untreated test piece 4. Has rust prevention effect. Also, as shown in FIG.
Describing the appearance 130 days after the start of the test,
For the test piece 1, no corrosion could be confirmed. Specimen 2 had mild corrosion on the entire front side and mild mild corrosion on the back side. The test piece 3 has a welded part 10 on the front side.
Was intensively corroded, and the back side had slight corrosion at the end of the welded portion 10. Further, little progress of rust was observed on the scale portion of the test piece 3. The front side of the test piece 4 had corrosion on the entire surface, and the back side had milder corrosion on the entire surface than the surface. As for the test piece 5, corrosion was found on the entire front surface and the entire rear surface including the scale portion.

Next, the parts storage standing test will be described. The test conditions of the parts warehouse leaving test were as follows: test pieces 2 to 5 were placed in a customs box at the bottom of the shelf of the parts warehouse and left for 130 days. As shown in FIG. 6, the appearance of the steel part 130 days after the start of the part storage standing test is described. Small corrosion points are scattered all over the front side of the test piece 2 and the back side is hardly corroded. Was. Small corrosion points were scattered all over the front side of the test piece 3 and the back side was hardly corroded. The test piece 4 had corrosion on the entire surface on the front side, and corrosion was concentrated on the end of the welded portion 10 on the rear side. The test piece 5 had corrosion on both front and back surfaces.

In the corrosion weight loss shown in FIG. 3, the test pieces 3 and 5 which are welded products have different weight loss levels from the test pieces 2 and 4 which are not welded products. Is included. When the initial values of the test pieces 3 and 5 which are the welded products are estimated from the results of the corrosion weight loss of the steel part subjected to the iron phosphate chemical conversion coating treatment, the graph shown in FIG. 4 is obtained. From the slope of the graph of FIG. 4, the corrosion speed was clearly different between the case where the iron phosphate conversion coating was applied and the case where the iron phosphate conversion coating was not applied. it can.

Further, there is no significant difference in the slope of the graph in FIG. 4 between the welded product and the non-welded product, that is, the test piece 2 and the test piece 3 and the test piece 4 and the test piece 5. However, the test pieces 3 and 5 which are welded products have portions that are easily rusted by heat, and portions that are covered with scale and are less likely to rust, and are offset as a whole. Therefore, it can be recognized that the test pieces 3 and 5 which are welded products are easily rusted.

The steel parts subjected to the heat cycle test and the steel parts subjected to the parts storage standing test both have different rusting methods on the front side and the back side. This is because the front side of the steel part is more exposed to outside air circulation than the back side.

Next, a description will be given of a load switching test for verifying a state change in sulfur hexafluoride gas. The test conditions for the load switching test were as follows: test piece 1 and test piece 2 were fixed in a gas switch, and load switching was performed 800 times. Regarding the test results of the load switching test, no change was observed in the appearance of any of the test pieces 1 and 2.

The hatched portions in FIGS. 5 and 6 indicate rusted portions of the steel part. Therefore, according to the embodiment, the following effects can be obtained. The corrosion of the test pieces 3 and 5 which are welded products is such that the front side starts to rust first and is in the most activated state. The scale-adhered portion on the back side (weld side) of the steel part was covered with rust as in the other parts without the iron phosphate chemical conversion coating treatment. However, the iron phosphate chemical conversion coating treatment hardly rusts. Therefore, a certain degree of rust-preventing effect can be expected even on a scale on which iron phosphate rides poorly. Corrosion can be suppressed by performing iron phosphate conversion coating treatment.

No formation of whiskers could be confirmed on the steel parts subjected to the iron phosphate chemical conversion coating treatment. Therefore, the whisker does not shorten the electrical insulation distance of the switch unit, and the whisker does not short-circuit due to detachment and attachment to the insulating unit. Therefore, the electrical performance of the gas switch can be maintained.

Since the production cost is lower than that of the conventional galvanization, the production cost of steel parts can be reduced. The embodiment according to the present invention may be modified and implemented as follows.

In the present embodiment, the iron phosphate conversion coating treatment is performed by immersing the steel parts in the iron phosphate treatment liquid. However, the iron phosphate conversion coating treatment may be performed by a spray method in which the iron parts are sprayed with the iron phosphate treatment liquid. Good. Also in this case, an iron phosphate conversion coating can be formed on the surface of a steel part.

In the present embodiment, the steel part is subjected to the surface chemical treatment with iron phosphate, but may be subjected to the surface chemical treatment with another phosphate such as zinc phosphate or zinc calcium phosphate. Further, a rust preventive film may be formed by performing a chromate treatment or the like. Even in this case, the built-in parts of the gas switch can have a rust-preventive effect.

In the present embodiment, the degreasing is performed by a chemical method using an organic solvent, an alkaline solution, or the like. However, a physical method such as a baking degreasing method may be used. Even in this case, it is possible to remove oily stains on the surface of the steel part.

In the present embodiment, the stain on the surface of the steel part
Although rust, scale, and the like are physically removed, they may be removed chemically such as pickling with sulfuric acid or hydrochloric acid. Even in this way, dirt, rust, scale, and the like on the surface of the steel part can be removed.

Although the embodiments have been described above, the technical ideas other than the claims that can be grasped from the embodiments will be described below.
The effects are described below together with those effects. -The built-in component of the gas switch according to claim 1, wherein the phosphate is iron phosphate, zinc phosphate or zinc calcium phosphate. In this case, since the cost is low and the productivity is excellent, the manufacturing cost of the parts can be reduced.

[0025]

According to the first aspect of the present invention, the rust prevention ability is high, and it is possible to prevent a decrease in electric performance in an oxygen-free state.

[Brief description of the drawings]

FIG. 1 is a list of tests performed in the present embodiment.

FIG. 2 is a list of test pieces used in tests performed in the present embodiment.

FIG. 3 (a) is a list of corrosion weight loss by a heat cycle test. (B) is a graph showing corrosion weight loss by a heat cycle test.

FIG. 4 is a graph showing the corrosion loss between a non-welded steel part and a welded steel part.

FIG. 5A is a front view of a test piece at the end of a heat cycle test. (B) is a rear view of the test piece at the end of the heat cycle test.

FIG. 6A is a front view of a test piece at the end of a parts storage standing test. (B) is a rear view of the test piece at the end of the parts storage standing test.

[Description of Signs] 1 to 5: test specimen, 10: welded part.

Claims (1)

[Claims] 1. A built-in component of a gas switch made of iron and steel and having a surface treatment of a chemical conversion coating.