CN112085320B - Method for graded evaluation of corrosion resistance of grounding material - Google Patents

Abstract

The invention belongs to the technical field of electric power engineering material experiments, and relates to a method for grading and evaluating the corrosion resistance of grounding materials. Typical grounding materials stainless steel, copper, and carbon steel are used as scoring benchmark samples, and the scoring references of 100 points for stainless steel, 80 points for copper, and 60 points for carbon steel are used to determine the scores of 100 points, 80 points, 60 points, 40 points, and 20 points. Value range of relative corrosion rate α; S2, determination of relative corrosion rate α of target sample; S3, score of target sample: according to relative corrosion rate α of target sample, search for the corresponding score in the corrosion resistance classification evaluation table, and record it as target sample Score points. The invention makes up for the absence of a uniform evaluation method for the corrosion resistance of grounding materials in current regulations, and can carry out grading and evaluation of corrosion resistance for various grounding materials, thereby providing guidance for the selection and use of grounding materials.

Description

A method for graded evaluation of corrosion resistance performance of grounding materials

technical field

The invention belongs to the field of grounding materials for electric power engineering, and relates to a method for grading and evaluating the corrosion resistance of grounding materials.

Background technique

The increasing requirements for grid stability and economy also put forward new requirements for grounding materials. In addition to the traditional carbon steel and galvanized steel, a variety of new grounding materials have emerged on the market. Although these grounding materials have their own advantages, they also have some functional shortcomings.

In addition, the Chinese patent "non-metallic composite carbon fiber copper-plated grounding material" with the publication number CN203535973U, the Chinese patent "preparation method of a corrosion-resistant aluminum alloy grounding material" with the publication number CN101976768A, and the Chinese patent "a new type of non-metallic Metal Anti-corrosion Bonding Material", the Chinese patent "Low Skin Effect Graphite Composite Grounding Material" with publication number CN203521648U also discloses the production method of some new grounding materials.

However, for the corrosion resistance of many grounding materials, there is no clear evaluation index, and there is no relevant standard to be based on, and there are certain blindness and controversy in its use. It is necessary to propose a method for evaluating the corrosion resistance of grounding materials, so as to carry out experimental research on various evaluation indicators, provide guidance for the selection and use of grounding materials, and make the actual construction of the grounding system engineering of power substations more operable and standardized .

Contents of the invention

The present invention mainly solves the technical problems existing in the prior art, and provides a method for graded evaluation of the corrosion resistance of grounding materials; Grounding materials such as galvanized steel, pure copper, copper-clad steel, zinc-clad steel, stainless steel, stainless steel-clad steel, conductive anti-corrosion coated steel and other grounding materials carry out classification and evaluation of corrosion resistance, so as to provide guidance for the selection and use of grounding materials.

Above-mentioned technical problem of the present invention is mainly solved by following technical scheme:

A method for grading and evaluating the corrosion resistance of grounding materials, the steps are as follows:

S1. Construct the corrosion resistance classification evaluation table: select a sample of a certain material as a comparison sample, select typical grounding materials stainless steel, copper, and carbon steel in the market as the scoring benchmark sample, and place a large number of scoring benchmark samples and comparative samples in the The comparison experiment of soil accelerated corrosion in the corrosion box, the relative corrosion rate α of each scoring standard sample was counted experimentally, with the scoring reference basis of stainless steel 100 points, copper 80 points, and carbon steel 60 points, according to the experimental statistics of each scoring standard sample Determine the relative corrosion rate α value range of 100 points, 80 points, and 60 points, and the relative corrosion rate α value range of each adjacent classification differs by an order of magnitude, and determine 40 points, 20 points The numerical range of relative corrosion rate α;

S2. Determination of the relative corrosion rate α of the target sample: weigh and record the target sample and the comparison sample with a smooth surface, place them in a corrosion box in parallel for soil accelerated corrosion comparison experiments, and measure the relative corrosion rate α of the target sample after corrosion;

S3. Scoring of the target sample: According to the relative corrosion rate α of the target sample, find the corresponding score in the corrosion resistance classification evaluation table, and record it as the score of the target sample.

More specifically, the relative corrosion rate α was tested with the Q235 carbon steel sample as a comparison sample.

More specifically, the corrosion resistance rating evaluation table is as follows:

More specifically, the evaluable grounding materials include hot-dip galvanized steel, pure copper, copper-clad steel, zinc-clad steel, stainless steel, stainless steel-clad steel, and conductive anti-corrosion coated steel.

More particularly, the soil accelerated corrosion comparative experiment: place the target sample with a smooth surface and the Q235 carbon steel comparison sample in parallel after weighing and recording, and place the soil thickness in each direction greater than 50mm, and control the temperature of the experimental soil and The humidity is 45°C and 25%, and it is left to stand for more than 15 days. After the sample is taken out, the surface corrosion products are removed and recorded by weighing.

More particularly, the relative corrosion rate calculation method: subtract the weight after the soil accelerated corrosion comparison experiment from the respective initial weights of the target sample and the Q235 carbon steel comparison sample to obtain the target sample weight loss W and the Q235 carbon steel comparison sample Weight loss W ₀ , calculate the exposed area S of the target sample and the exposed area S ₀ of the comparison sample of Q235 carbon steel according to the size of the sample, and calculate the relative corrosion rate α of the target sample according to the following formula:

The present invention has the following advantages: According to the corrosion resistance test results of typical grounding materials on the market, stainless steel has the best corrosion resistance, followed by copper, and carbon steel is the worst. Carbon steel has 60 points, copper has 80 points, and stainless steel has 100 points. Value distribution, the corrosion resistance rating evaluation table constructed in this way ensures the differentiation of the scores. It makes up for the fact that there is no uniform evaluation method for the corrosion resistance of grounding materials in the current regulations, and can be used for grounding materials such as hot-dip galvanized steel, pure copper, copper-clad steel, zinc-clad steel, stainless steel, stainless steel-clad steel, conductive anti-corrosion coated steel, etc. Carry out the classification and evaluation of corrosion resistance performance, so as to provide guidance for the selection and use of grounding materials.

Description of drawings

Figure 1 is a schematic diagram of a soil accelerated corrosion comparison experiment.

Fig. 2 is a flowchart of the present invention.

In the figure: 1-experimental soil, 2-sample.

detailed description

The technical solutions of the present invention will be further specifically described below through the embodiments and in conjunction with the accompanying drawings.

Referring to Figure 1 and Figure 2, a method for grading and evaluating the corrosion resistance of grounding materials, the steps are as follows:

S1. Construct the corrosion resistance classification evaluation table: select the Q235 carbon steel sample as the comparison sample, select the typical grounding materials stainless steel, copper, and carbon steel in the market as the scoring reference sample, and place a large number of scoring reference samples and comparison samples in the The soil accelerated corrosion comparison experiment in the corrosion box, the scoring reference sample with a smooth surface and the Q235 carbon steel comparison sample were weighed and recorded, and then placed in parallel in the corrosion box. The thickness of the soil in each direction is greater than 50mm. Control the temperature and humidity of the experimental soil 1 at 45°C and 25%, let it stand for more than 15 days, take out sample 2, remove the surface corrosion products, weigh and record.

The relative corrosion rate calculation method: subtract the weight after the soil accelerated corrosion comparison experiment from the respective initial weights of the scoring reference sample and the Q235 carbon steel comparison sample to obtain the weight loss W of the scoring reference sample and the weight loss W of the _Q235 carbon steel comparison sample. , calculate the exposure area S of the target sample and the exposure area S ₀ of the comparison sample of Q235 carbon steel according to the size of the sample, and calculate the relative corrosion rate α of the target sample according to the following formula:

Experimental statistics of the relative corrosion rate α of each scoring benchmark sample, with the scoring reference basis of 100 points for stainless steel, 80 points for copper, and 60 points for carbon steel, according to the relative corrosion rate α of each scoring benchmark sample in experimental statistics, determine the score 100 points , 80 points, and 60 points relative corrosion rate α value range, the relative corrosion rate α value range of each adjacent classification differs by an order of magnitude, and based on this, determine the relative corrosion rate α value range of 40 points and 20 points by analogy; construct The corrosion resistance rating evaluation table is as follows:

S2. Determination of the relative corrosion rate α of the target sample: the target sample with a smooth surface and the comparison sample were weighed and recorded, and then placed in parallel in the corrosion box for soil accelerated corrosion comparison experiments, and the target sample with a smooth surface was compared with Q235 carbon steel After weighing and recording the samples, place them in parallel in the corrosion box. The thickness of the soil in each direction is greater than 50mm. Re-record. After corrosion, measure the relative corrosion rate α of the target sample, and the calculation method of the relative corrosion rate is: subtract the weight after the soil accelerated corrosion comparison experiment from the respective initial weights of the target sample and the Q235 carbon steel comparison sample to obtain the target sample weight loss W and The weight loss W ₀ of the Q235 carbon steel comparison sample is calculated according to the size of the sample, and the exposure area S of the target sample and the exposure area S ₀ of the Q235 carbon steel comparison sample are calculated, and the relative corrosion rate α of the target sample is calculated according to the following formula:

S3. Scoring of the target sample: According to the relative corrosion rate α of the target sample, find the corresponding score in the corrosion resistance classification evaluation table, and record it as the score of the target sample.

Example: Graded evaluation of the corrosion resistance of pure copper grounding materials.

1. Contrast experiment of soil accelerated corrosion: Weigh and record the pure copper sample with smooth surface and the Q235 carbon steel comparison sample and place them in parallel in the corrosion box. The soil thickness in each direction is greater than 50mm. and 25%, let it stand for 30 days, after taking out the sample, remove the surface corrosion products and weigh and record.

2. Calculate the relative corrosion rate: Subtract the weight after the soil accelerated corrosion comparison experiment from the respective initial weights of the pure copper sample and the Q235 carbon steel comparison sample to obtain the target sample weight loss W=0.0279g and the Q235 carbon steel comparison sample weight loss W ₀ ＝0.4062g, calculate the target sample exposure area S=15.7cm ² and Q235 carbon steel comparison sample exposure area S ₀ ＝15.6cm ² according to the sample size, calculate the relative corrosion rate of the target sample according to the following formula α= 0.06825:

3. Graded evaluation of corrosion resistance: the relative corrosion rate of pure copper grounding material is 0.06825, and the corrosion resistance score of pure copper grounding material is 80 points according to the table below.

The present invention only provides evaluation cases of pure copper grounding materials, and the evaluation grounding materials include hot-dip galvanized steel, pure copper, copper-clad steel, zinc-clad steel, stainless steel, stainless steel-clad steel, conductive anti-corrosion coated steel, etc. Relative corrosion rate α can also be selected from other materials for comparison, and the range of α value in the corresponding corrosion resistance classification evaluation table should be adjusted appropriately.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention belongs can make various modifications or supplements to the described specific embodiments or adopt similar methods to replace them, but they will not deviate from the spirit of the present invention or go beyond the definition of the appended claims range.

Claims (5)

1. A method for graded evaluation of grounding material corrosion resistance, characterized in that the steps are as follows: S1. Construct the corrosion resistance classification evaluation table: select a sample of a certain material as a comparison sample, select typical grounding materials stainless steel, copper, and carbon steel in the market as the scoring benchmark sample, and place a large number of scoring benchmark samples and comparative samples in the The soil accelerated corrosion comparative experiment was carried out in the corrosion box; the target sample with a smooth surface and the comparison sample were weighed and recorded and placed in parallel in the corrosion box, the temperature and humidity of the experimental soil were controlled, and the soil was left to stand for several days. After taking out the sample, remove The surface corrosion products are weighed and recorded; subtract the weight after the soil accelerated corrosion comparison experiment from the respective initial weights of the target sample and the comparison sample to obtain the weight loss W of the target sample and the weight loss W 0 of the comparison sample, and calculate the target weight loss W ₀ based on the sample size. The exposed area S of the sample and the exposed area S ₀ of the comparison sample are used to calculate the relative corrosion rate α of the target sample according to the following formula:

Experimental statistics of the relative corrosion rate α of each scoring benchmark sample, with the scoring reference basis of 100 points for stainless steel, 80 points for copper, and 60 points for carbon steel, according to the relative corrosion rate α of each scoring benchmark sample in experimental statistics, determine the score 100 points , 80 points, and 60 points relative corrosion rate α value range, the relative corrosion rate α value range of each adjacent classification differs by an order of magnitude, and based on this, the relative corrosion rate α value range of 40 points and 20 points is determined by analogy; S2. Determination of the relative corrosion rate α of the target sample: weigh and record the target sample and the comparison sample with a smooth surface and place them in parallel in the corrosion box to conduct a soil accelerated corrosion comparison experiment, and measure the relative corrosion rate α of the target sample after corrosion; S3. Scoring of the target sample: According to the relative corrosion rate α of the target sample, find the corresponding score in the corrosion resistance classification evaluation table, and record it as the score of the target sample. 2. A method for graded evaluation of corrosion resistance of grounding materials according to claim 1, characterized in that the relative corrosion rate α is tested with a Q235 carbon steel sample as a comparison sample. 3. a kind of method for graded evaluation of corrosion resistance of grounding material according to claim 1, is characterized in that, the graded evaluation table of corrosion resistance is as follows:

. 4. A method for graded evaluation of corrosion resistance of grounding materials according to claim 1, wherein the grounding materials used for graded evaluation of corrosion resistance include hot-dip galvanized steel, pure copper, copper-clad steel, zinc Any one of clad steel, stainless steel, stainless steel clad steel, conductive anti-corrosion coated steel. 5. The method for grading and evaluating the corrosion resistance of grounding materials according to claim 1, wherein the soil accelerated corrosion contrast experiment process is as follows: the target sample with smooth surface and the Q235 carbon steel contrast sample weighed After re-recording, put them in parallel in the corrosion box, the soil thickness in each direction is greater than 50mm, control the temperature and humidity of the experimental soil at 45°C and 25%, and let it stand for more than 15 days. After taking out the samples, remove the surface corrosion products and weigh them for recording.

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