Some standard content:
ICS 13.060.01
Preparation number: 3060-1999
Petroleum and natural gas industry standard of the People's Republic of China SY/T 0026—1999
Test method for corrosivity of water
Test method for corrosivity of water1999 — 05 - 17 Issued
State Administration of Petroleum and Chemical Industry
Implemented on 12-01-1999
SY/T 0026—1999
3 Test medium
Test device
Test method
Test results
Appendix A (Appendix to the standard)
Standard for corrosivity classification of media in pipelines and storage tanksSY/T 00261999
This standard is compiled by Jianghan Petroleum Pipeline Bureau Survey and Design Institute after revising SYJ26-87 (water erosion test method) according to the task assigned by the former China National Petroleum Corporation (98) Zhongyou Jijianzi No. 33 "Notice on the 1998 National Standard Industry Standard Revision Plan for the Oil and Gas Industry" and the revised standard has the following changes compared with the original SYJ26-87: the compilation instructions in the original standard have been deleted; the first chapter of the original standard has been deleted
General provisions; the preface has been added; the first chapter of the scope has been added; the fourth chapter of the test device has been added; the second chapter of the composition of the sample has been added; the second chapter of the field test has been added; the fourth chapter of the chemical reagent has been added; the fifth chapter of the composition of the sample has been added; the fifth chapter of the chemical reagent has been added.
This standard replaces SYI 2(—87 from the date of implementation. Appendix A of this standard is the appendix of the standard.
This standard was proposed by China National Petroleum Corporation. This standard is under the jurisdiction of the Planning and Design Institute of China National Petroleum Corporation. The drafting unit of this standard: Jianghan Shizhuang Administration Bureau Survey and Design Institute. Who are the main drafters of this standard? Gao Feng, Jia Hengyao, Feng Xiaobei, Sun Kui. This standard was first revised and issued in May 1987 and revised for the first time in May 1999. TV
1 ScopebzxZ.net
Petroleum and Natural Gas Industry Standard of the People's Republic of China Test method for corrosivity of water
Tesl method for corrosivity of waterSY/T 0026—1999
Replaces SYJ 26 87
This standard specifies the test method for determining the corrosion rate of steel by water media during the construction and production of oil and gas fields. This standard is applicable to the evaluation of the corrosion of steel by water media. 2 Test specimens
2.1 Composition of test specimens
2.1.1 The main components of the test specimens and the types and contents of impurity elements should be known. 2.1.2 The material of the test specimen should be consistent with the composition of the material actually used. When the material actually used cannot be determined, Q235A steel should be used. 2.2 Specifications of test specimens
2.2.1 The shape and size of the test specimen should be determined according to the original conditions of the test material and the test container used. The test specimen with the largest surface area per unit mass and the smallest ratio of the side area to the total area should be used as much as possible. In general, the area perpendicular to the rolling or forging direction shall not be less than half of the total area of the test specimen. The surface area of each test specimen shall not be less than 10cm22.2.2 The recommended test specimen specifications are as follows:
Dimensions; 1×6×h, mm: 50×25× (2 -5); Overall dimensions f: 1 ×6×h, mm: 76×13× (1.5--3). Depending on the test date, other shapes and sizes of specimens can also be selected. 2.2.3 The specifications of the specimens for batch tests should be the same. 2.3 Preparation of specimens
2.3.1 When sampling on plates or materials, they should be cut along the rolling direction. If the rolling direction is unclear or not cut along the rolling direction, it must be noted in the report. When cutting thin slice specimens on thick plates, the surface part close to the plate should be selected. Avoid the edge of the plate, and the distance from the edge is generally not less than 5mma
2.3.2 The specimens are processed by various mechanical methods, but the possible changes in the performance of the specimens must be avoided. 2.3.3 In order to improve the uniformity of the test results, the original metal surface layer can be removed by sandpaper grinding or other mechanical methods. The final surface of the sample is ground with 120-grit water sandpaper. Only the same material sample can be ground on each piece of sandpaper (cloth). 2.3.4 The polished sample should be inspected on the surface. Samples with obvious defects (slag inclusions, pores, cracks) should be removed. 2.3.5 Drill a hole about 5mm from the edge of the sample. The hole diameter should not be greater than 4mm. Mark a recognizable number on each side. The hole diameter of the sample for on-site testing can be appropriately increased.
2.3.6 Measure the size of the qualified sample to calculate the area, remove the grease with an organic solvent (acetone), scrub it in anhydrous ethanol, and finally soak it in clean anhydrous ethanol for dehydration. 2.3.7 The dehydrated sample should be immediately dried with filter paper, placed in a desiccator and dried for 10 to 24 hours before weighing. 2.3.8 The sample area should be calculated accurately to [%. 2.3.9 The sample weight should be accurate to 0.1 mg
2.3.10 The sample should be prevented from being contaminated during weighing and mixing operations. State Administration of Petroleum and Chemical Industry approved 1099-12-01 on May 17, 1999 for implementation
2.3.11 At least three parallel samples should be taken for each test. 3 Test medium
SY/T 0026—1999
3.1 The test medium should be taken from the production site under normal circumstances, and the storage time should not be too long. The sampling device should be vented to remove air (using nitrogen or on-site water, etc.)
3.2 The main components of the test medium should be determined in time. 3.3 When the test medium is prone to property changes when in contact with air, a closed test process should be adopted. 3.4 The amount of test medium used is not less than 20mL per 1cm2 sample surface area. 3.5 The test temperature is generally room temperature. When the on-site medium temperature is higher than 40C, a constant temperature test should be carried out according to the on-site temperature, and the test temperature difference should be changed to ±2.
4 Test equipment
4,1 The container material should be inert to the test medium, commonly used are glass, plastic, ceramics, etc. 4.2 According to the test temperature requirements, select a constant temperature device that can keep the test medium within the specified temperature range. 4.3 The material of the sample holder should be inert to the test medium and the sample, and its contact area with the sample should be as small as possible. 4.4 When the test is dynamic, the corresponding device should be added according to the different rotating objects. 5 Test method
5.1 Indoor test
5.1.1, Indoor test is divided into two methods: static exposure and dynamic exposure. 5.1.2 Static water uses static exposure method, dynamic water uses dynamic exposure method. 5.1.2.1 Static exposure method: The sample should be installed in the middle of the test medium, the distance between the upper end of the sample and the wave surface should be greater than 5cm, and the sample spacing should be more than 2cn.
5.1.2.2 Dynamic exposure method: The dynamic exposure method uses rotating samples or stirring media to achieve movement. The requirements for sample installation position are the same as 5.1.2.1.
5.2 On-site test
5.2,1 On-site test can better reflect the actual corrosion situation. If conditions permit, on-site test should be carried out. 5.2.2 On-site test can be carried out by directly hanging the sample in the large tank and installing the hanging device in the general road. 5.3 Test time
5.3.1 The test time refers to the whole time from when the sample is immersed in the medium and reaches a certain temperature until the sample is taken out. 5.3.2 The calculation of the test time should be accurate to 0.1% of the whole test time. 5.3,3 The most commonly used test cycle is 48 to 168 hours. For the test cycle of highly corrosive media, the lower limit is taken, and for the test cycle of weakly corrosive media, the upper limit is taken. The on-site coupon test cycle can be appropriately extended. 5.4 Chemical reagents
5.4.1 The chemical reagents involved in the test (unless otherwise specified) shall all meet the chemical purity standards specified by the state. 5.4.2 Nethanone.
5.4.3 Anhydrous ethanol.
5.4.4 Hydrochloric acid cleaning solution - Use 10% or 15% hydrochloric acid to pickle the corrosion inhibitor; take 1L of hydrochloric acid (relative density 1.19), weigh 20g of antimony trioxide and 50g of stannous fluoride and dissolve them in hydrochloric acid. 5.4.5 Sodium hydroxide neutralization solution - weigh 65g of sodium hydroxide and dissolve it in 1L of water. 5.5 Method for removing corrosion products
5.5.1 After the sample is taken out of the test medium, it should be rinsed with water immediately, and loose products on the surface should be removed with a hard brush. 5.5.2 The washed sample should be dried with filter paper and placed in hydrochloric acid cleaning solution to further remove corrosion products: if 5.4.4 The first formula of the acid cleaning solution of salt 2
SY/T 0026--1999
, the longest cleaning time for one time is 25rri1e5.5.3, the sample after acid washing should be immediately rinsed in tap water after being taken out, and then soaked in sodium hydroxide neutralizing solution for no less than 1min after being blotted with filter paper. The neutralized sample should be rinsed with tap water again. 5.5.4 The above process can be repeated for the sample that is not cleaned once. 5.5.5 The sample that has passed the cleaning should be soaked in water with filter paper and then soaked in anhydrous ethanol for dehydration for 5minm5.5.6 The sample that has been soaked and dehydrated should be dried with filter paper and then placed in a desiccator for 10-24h and weighed. 5.5.7 For the sample that can be cleaned by acid washing once, a blank test with the same acid washing time as the sample should be conducted (the number of blank samples should not be less than two), and 12 of the average weight loss of the blank sample should be deducted from the weight loss of the sample as the weight loss of the sample. 5.5.8 For the samples that can only remove the corrosion products after multiple pickling, the cumulative weight loss after each cleaning is plotted with the number of cleanings, as shown in Figure 1. The BC segment straight line in the figure is extended to the weight loss, and the intersection point is the weight loss of the sample. Number of cleanings (time)
Figure 1 Sample weight loss curve
6 Test results
6.1 Inspection of samples
6.1.1 First, check the appearance of the sample. When serious corrosion is found at the numbered area, the sample is invalid. When there are less than three valid samples, the test should be repeated.
6.1.2 Describe and record the corrosion condition of the sample surface. 6.1.3 If the pitting on the sample surface is obvious, use a depth gauge to measure the depth in a representative area, describe the number, size, shape and distribution of the pits, and record them. 6.2 Result Expression
Calculate the difference between the weight loss per unit area and the average value of each group of parallel samples after weighing. When the following formula is satisfied, the result shall be used. Am s0.2mu
In the formula; A
The difference between the weight loss per unit area of each parallel sample and the average value, g/cm2: ...The arithmetic mean of the weight loss per unit area of each parallel sample, g/cm2;
The coefficient related to the number of samples can be obtained according to Table 1, the table value table
SY/T 00261999
6.2.2 When the test results cannot meet the requirements of 6.2.1, the test should be repeated. The number of samples during the re-test can be selected according to the value of the following formula.
u = 0.2mm
where △m takes the largest absolute value. When 1.3>μ20.72, the number of samples is 4; when .72>≥0.51, the number of samples is 5.
6,2.3 The formula for calculating the corrosion rate is as follows: u 8.76 x 104× ms-to)
Wu Zhong: 2-
-corrosion rate, mm/α;
—sample weight loss, g;
S—-sample exposure area, cr?,
t——test time, h;
p—sample relative density, g/cm2.
6.3 Test report
The test report should mainly include the following contents;-Water sampling location (test location);
-Water sampling date (latter period of hanging);
Specimen material;
Exposure method;
Test time, h;
-Test temperature,;
Corrosion rate, mm/year;
-Maximum pitting depth, mm;
-Appearance description;
-Corrosion resistance classification standard [see Appendix A (Appendix to the standard)];-Remarks if necessary:
Signature of the test, verification and approval personnel. Item
Average corrosion rate
mm/year
Pitting corrosion rate
mm/year
SY/T 0026—1999
Appendix A
(Appendix to the standard)
Standard table for classification of media corrosion in pipelines and reservoirs A1
1Standard for classification of media corrosion in pipelines and reservoirs Low
0.025 - 0.125
0.305~0.610
0.126-0.254
0.611-2.438
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