CN106802274A - Assay method of the corrosion inhibiter to Oil/Gas Pipe weld corrosion control effect - Google Patents
Assay method of the corrosion inhibiter to Oil/Gas Pipe weld corrosion control effect Download PDFInfo
- Publication number
- CN106802274A CN106802274A CN201611254104.0A CN201611254104A CN106802274A CN 106802274 A CN106802274 A CN 106802274A CN 201611254104 A CN201611254104 A CN 201611254104A CN 106802274 A CN106802274 A CN 106802274A
- Authority
- CN
- China
- Prior art keywords
- corrosion
- corrosion inhibiter
- oil
- electrode
- control effect
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N17/00—Investigating resistance of materials to the weather, to corrosion, or to light
- G01N17/02—Electrochemical measuring systems for weathering, corrosion or corrosion-protection measurement
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Biodiversity & Conservation Biology (AREA)
- Ecology (AREA)
- Environmental & Geological Engineering (AREA)
- Environmental Sciences (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)
Abstract
The invention discloses a kind of corrosion inhibiter to the assay method of Oil/Gas Pipe weld corrosion control effect, the working electrode of electrochemical test system is made by oneself with the welding point material of oil-gas pipeline：Welding point material is divided and is cut into mother metal area, the near-thermal zone of influence, four regions in remote heat affected area and weld seam；Using the inner-walls of duct face drawn materials as working electrode working face, other faces are non-working surface, a piece electric lead for tape insulation skin is connected using soldering at the back side of working face, then non-working surface and tin welding spot is encapsulated using epoxy resin, only exposes the working face of electrode；The use of electric current induction precision is ± 100nA~± 1A, minimum current resolution ratio is tested for the electrochemical test system of 1nA；The inhibition efficiency of corrosion inhibiter is calculated using the corrosion potential of measurement.Compared with prior art, the positive effect of the present invention is：Using assay method of the invention, the corrosion control effect of corrosion inhibiter Welded Joints can be more accurately evaluated.
Description
Technical field
The present invention relates to corrosion inhibiter to the assay method of Oil/Gas Pipe weld corrosion control effect.
Background technology
There is certain difference in corrosion inhibiter, be that this need to assess weldering to the preservative efficiency of pipeline mother metal, thermal deformation area and weld seam
The corrosion risk in area is stitched, the validity of corrosion inhibiter is verified, corrosion protection design safety is ensured.The research of country's this respect is little at present,
Weak foundation, causes anticorrosion process to there is blank, and urgent need is filled up.Weld decay belongs to the very serious part of harm
Galvanic corrosion, often results in the failure of welding position, and its economic loss is considerable.For the defeated pipeline corrosion of domination set,
Conventional method is included carbon steel piping filling corrosion inhibiter, is used using corrosion resistant alloy tubing (including multiple tube), inner surface of pipeline
Corrosion-inhibiting coating and nonmetallic bushing pipe etc..Wherein most universal, most effective, the most economical method of application is still filling anti-corrosion.
Corrosion inhibiter has obtained extensive utilization as an economy, anti-corrosion means effective, simple to operate in oil and natural gas industry,
It is to consider corrosion inhibiter to whole gathering line material when but in general, selection corrosion inhibiter is as Corrosion prevention scheme
Corrosion.It is often ignored to the corrosion behavior of weld seam for corrosion inhibiter.From existing Research Literature, document money both domestic and external
Research in material on corrosion inhibiter to weld seam corrosion impact is rarely reported.
For the evaluation method of oil gas corrosion inhibiter, can mainly be referred to by following standard, SY/T 5273-2014《Oil field
Recovered water corrosion inhibiter method of evaluating performance》, SY/T 7025-2014《Acid-soluble oil gas field corrosion inhibiter performance test room evaluation side
Method》And standard ASTM G170-06 (2012)《Evaluate and calibrating oil field, the standard directive guide of refinery's corrosion inhibiter》, in these standards
Corrosion inhibiter dissolubility, emulsibility, foaming characteristic, corrosion inhibition rate method of testing are specified.In terms of the evaluation of corrosion inhibition, together
When with reference to JB/T 7901-1999《Uniform Corrosion Method of Laboratory Immersion Test method》, test piece immersion evaluation corrosion inhibiter work
With.In these standards, the method explanation all do not evaluated weld seam corrosiveness effect corrosion inhibiter.
The content of the invention
In order to overcome the shortcoming of prior art, the invention provides a kind of corrosion inhibiter to Oil/Gas Pipe weld corrosion control effect
Assay method.
The technical solution adopted in the present invention is：A kind of measure side of corrosion inhibiter to Oil/Gas Pipe weld corrosion control effect
Method, comprises the following steps：
Step one, the working electrode for making electrochemical test system by oneself with welding point material：
Welding point material is divided and is cut into mother metal area, the near-thermal zone of influence, four regions in remote heat affected area and weld seam；Will
The inner-walls of duct face drawn materials as working electrode working face, other faces be non-working surface, working face the back side use
Soldering connects an electric lead for tape insulation skin, is then encapsulated non-working surface and tin welding spot using epoxy resin, only reveals
Go out the working face of electrode；
Step 2, using electric current induction precision be ± 100nA~± 1A, minimum current resolution ratio for 1nA electrochemistry survey
Test system is tested：
OCP is first determined one by one to determine the circuit stable connection of test system, is determined after test system stabilization
Polarization curve；After thermostat water bath equilibrium temperature, the method scanned using potentiodynamic polarization, first test is not added with being welded during corrosion inhibiter
The mother metal of joint and the corrosion potential of heat affected area；Then the mother metal of welding point and heat affected area when re-test adds corrosion inhibiter
Corrosion potential situation of change；
Step 3, the corrosion potential measured using step 2 calculate the inhibition efficiency of corrosion inhibiter.
Compared with prior art, the positive effect of the present invention is：The present invention is successfully connect welding using the method for electrochemistry
The corrosion and corrosion inhibiter action effect of head are connected, and using assay method of the invention, can more accurately evaluate corrosion inhibiter pair
The corrosion control effect of welding point, specific advantage performance is as follows：
1st, the materials of weld seam：This method of testing is mainly for bigbore oil-gas gathering and transportation carbon steel piping welding point, bore
Small pipeline, weld seam different parts materials are difficult, and welding point different zones current potential difference is small, it is not easy to test out potential difference.
2nd, the influence of processing：Welding point cutting uses Cold-forming process, material was notheated in process
Amount.
3rd, electrochemical workstation test susceptibility：The minimum current that equipment can be tested is equal to or less than 10-9A, it is minimum
Voltage 10-4V, reference electrode stabilization.
Specific embodiment
A kind of corrosion inhibiter comprises the following steps to the assay method of Oil/Gas Pipe weld corrosion control effect：
1st, the preparation of working electrode：
In electro-chemical test, electrochemical test system is made up of three-electrode system, respectively working electrode, reference electrode
And auxiliary electrode.Wherein reference electrode is saturated calomel electrode or silver chloride electrode, and auxiliary electrode is graphite electrode or platinum
Electrode, reference electrode and auxiliary electrode commercially can arbitrarily buy, and working electrode needs self-control, is to use welding point
The homemade electrode of material.Welding point is divided into mother metal area, the near-thermal zone of influence, four regions in remote heat affected area and weld seam, according to
The actual conditions of welding point, four regions are numbered and are fabricated to working electrode.
After the material in the region of weld seam is divided to be cut out, in the inner-walls of duct face drawn materials, (corrosive medium connects
Contacting surface) make marks, finally as the working face of working electrode, other faces are non-working surface, and one is connected in the behind of working face
The electric lead of tape insulation skin, is connected using soldering, and non-working surface and tin welding spot are encapsulated using epoxy resin then, is only revealed
Go out the working face of electrode.
2nd, specific test
Use electrochemical workstation, electric current induction precision (current range：± 100nA~± 1A, minimum current resolution ratio
When 1nA) testing, OCP is first determined one by one and determines circuit connection effect, determine polarization curve at once after stable system, respectively
Time of the individual electrode in detected solution is immersed in before determining polarization curve is consistent.It is advanced in thermostat water bath equilibrium temperature
Row OCP is scanned, then carries out potentiodynamic polarization test.Test parameters is set：OCP testing time 600s；Polarization model
Enclose (with respect to OCP)：Anode+200mV, negative electrode -150mV, sweep speed：0.6mV/s.
Using potentiodynamic polarization scan method, in the case of not added with corrosion inhibiter, test welding point mother metal and
The corrosion potential of heat affected area.Corrosion inhibiter is subsequently adding, the potential change situation after adding corrosion inhibiter is retested.Computing formula
For：
In formula：--- add the average value of mother metal current potential before corrosion inhibiter；
--- add the average value of the preceding heat affected area current potential of corrosion inhibiter；
--- add the average value of mother metal current potential after corrosion inhibiter；
--- add the average value of heat affected area current potential after corrosion inhibiter.
X is the inhibition efficiency of corrosion inhibiter, and according to the principle of weld corrosion, the corrosion power resources of weld seam are in corrosion potential
Difference, corrosion potential difference and corrosion current are directly proportional, and corrosion current and corrosion rate are directly proportional, inhibition efficiency computing formula：
Not add corrosion inhibiter corrosion rate,To add the corrosion rate after corrosion inhibiter.Therefore can calculate
Go out to be calculated using potential difference meter the computing formula of corrosion inhibiter efficiency.
The test effect of the inventive method is as follows：
Mother metal and the heat affected area of same section welding point are taken, 10 replica tests are carried out, and test is added respectively
Corrosion potential before and after corrosion inhibiter, test result is shown in Table 1.
The corrosion potential of table 1
First, the evaluation of A classes uncertainty
Without specific functional relation between concrete operations and personnel's influence factor in experimentation, so during evaluation
Can be carried out using A classes method.
1st, the optimum evaluation of a
Similarly：
2nd, standard deviation S presses Bessel Formula
Similarly：
3rd, average stdev
4th, component uncertainty
Similarly：
2nd, the evaluation of type B standard uncertainty
1st, the partial uncertainty that the electrochemical workstation apparatus measures error of indication is introduced
The error of indication of work station is no more than 0.01%.
/ 2, the partial uncertainty that electrochemical workstation instrument current potential resolution ratio is introduced
U2=0.29 δx=2.9 × 10-6The current potential resolution ratio of work station is 0.0001V.
3rd, the evaluation of combined standard uncertainty
4th, the evaluation of expanded uncertainty U
U=KUx=2 × 0.059=0.118
Wherein, K is Coverage factor, typically takes 2.Therefore using this method of testing, uncertainty of measurement is：X=0.75 ±
0.118。
Claims (7)
1. assay method of a kind of corrosion inhibiter to Oil/Gas Pipe weld corrosion control effect, it is characterised in that：Comprise the following steps：
Step one, the working electrode for making electrochemical test system by oneself with the welding point material of oil-gas pipeline：
Welding point material is divided and is cut into mother metal area, the near-thermal zone of influence, four regions in remote heat affected area and weld seam；To be taken
The inner-walls of duct face of material as working electrode working face, other faces be non-working surface, use soldering at the back side of working face
, be encapsulated for non-working surface and tin welding spot using epoxy resin then by a piece electric lead for tape insulation skin of connection, only exposes electricity
The working face of pole；
Step 2, using electric current induction precision be ± 100nA~± 1A, minimum current resolution ratio for 1nA electro-chemical test system
System is tested：
OCP is first determined one by one to determine the circuit stable connection of test system, and polarization is determined after test system stabilization
Curve；After thermostat water bath equilibrium temperature, the method scanned using potentiodynamic polarization, first test is not added with being connect during corrosion inhibiter
The mother metal of head and the corrosion potential of heat affected area；Then the corruption of the mother metal and heat affected area of welding point when re-test adds corrosion inhibiter
Erosion potential change situation；
Step 3, the corrosion potential measured using step 2 calculate the inhibition efficiency of corrosion inhibiter.
2. assay method of the corrosion inhibiter according to claim 1 to Oil/Gas Pipe weld corrosion control effect, it is characterised in that：
Determine polarization curve before ensure each electrode be immersed in detected solution in time consistency.
3. assay method of the corrosion inhibiter according to claim 1 to Oil/Gas Pipe weld corrosion control effect, it is characterised in that：
The method of the potentiodynamic polarization scanning is first to carry out OCP scanning, then carries out potentiodynamic polarization test.
4. assay method of the corrosion inhibiter according to claim 3 to Oil/Gas Pipe weld corrosion control effect, it is characterised in that：
The test parameters of potentiodynamic polarization scanning is：OCP testing time 600s；Polarization scope with respect to OCP is：
Anode+200mV, negative electrode -150mV, sweep speed：0.6mV/s.
5. assay method of the corrosion inhibiter according to claim 1 to Oil/Gas Pipe weld corrosion control effect, it is characterised in that：
It is calculated as follows the inhibition efficiency X of corrosion inhibiter：
In formula：It is the average value of mother metal current potential before addition corrosion inhibiter；
To add the average value of the preceding heat affected area current potential of corrosion inhibiter；
It is the average value of mother metal current potential after addition corrosion inhibiter；
It is the average value of heat affected area current potential after addition corrosion inhibiter.
6. assay method of the corrosion inhibiter according to claim 1 to Oil/Gas Pipe weld corrosion control effect, it is characterised in that：
The reference electrode of the electrochemical test system is saturated calomel electrode or silver chloride electrode.
7. assay method of the corrosion inhibiter according to claim 1 to Oil/Gas Pipe weld corrosion control effect, it is characterised in that：
The auxiliary electrode of the electrochemical test system is graphite electrode or platinum electrode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611254104.0A CN106802274A (en) | 2016-12-30 | 2016-12-30 | Assay method of the corrosion inhibiter to Oil/Gas Pipe weld corrosion control effect |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611254104.0A CN106802274A (en) | 2016-12-30 | 2016-12-30 | Assay method of the corrosion inhibiter to Oil/Gas Pipe weld corrosion control effect |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106802274A true CN106802274A (en) | 2017-06-06 |
Family
ID=58984277
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201611254104.0A Pending CN106802274A (en) | 2016-12-30 | 2016-12-30 | Assay method of the corrosion inhibiter to Oil/Gas Pipe weld corrosion control effect |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106802274A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108387506A (en) * | 2018-02-12 | 2018-08-10 | 青岛钢研纳克检测防护技术有限公司 | Probe and method for monitoring titanium alloy pipeline crevice corrosion in flowing seawater |
| CN111707606A (en) * | 2020-05-08 | 2020-09-25 | 中国船舶重工集团公司第七二五研究所 | Copper-nickel alloy pipeline internal welding heat affected zone corrosion electrochemical testing device |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002025249A2 (en) * | 2000-09-22 | 2002-03-28 | Buechler Markus | Electrochemical cell, use of the electrochemical cell, and method for electrolytically contacting and electrochemically influencing surfaces |
| CN104833630A (en) * | 2015-05-15 | 2015-08-12 | 中国石油大学(华东) | Electrochemical testing device of welding connector in thin liquid membrane and operation method of electrochemical testing device |
-
2016
- 2016-12-30 CN CN201611254104.0A patent/CN106802274A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002025249A2 (en) * | 2000-09-22 | 2002-03-28 | Buechler Markus | Electrochemical cell, use of the electrochemical cell, and method for electrolytically contacting and electrochemically influencing surfaces |
| CN104833630A (en) * | 2015-05-15 | 2015-08-12 | 中国石油大学(华东) | Electrochemical testing device of welding connector in thin liquid membrane and operation method of electrochemical testing device |
Non-Patent Citations (2)
| Title |
|---|
| 张金钟等: "几种油气管道缓蚀剂的筛选评价", 《腐蚀与防护》 * |
| 张金钟等: "动电位极化法研究缓蚀剂对焊缝的作用分析", 《全面腐蚀控制》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108387506A (en) * | 2018-02-12 | 2018-08-10 | 青岛钢研纳克检测防护技术有限公司 | Probe and method for monitoring titanium alloy pipeline crevice corrosion in flowing seawater |
| CN111707606A (en) * | 2020-05-08 | 2020-09-25 | 中国船舶重工集团公司第七二五研究所 | Copper-nickel alloy pipeline internal welding heat affected zone corrosion electrochemical testing device |
| CN111707606B (en) * | 2020-05-08 | 2024-03-29 | 中国船舶重工集团公司第七二五研究所 | Electrochemical testing device for corrosion of welding heat affected zone inside copper-nickel alloy pipeline |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101762454B (en) | Dual-ring electrochemical dynamic potential reactivating evaluating method for diphase stainless steel intercrystalline corrosion sensitivity | |
| Faritov et al. | Improvement of the linear polarization resistance method for testing steel corrosion inhibitors | |
| CN108680492B (en) | Method for measuring corrosion depth in galvanic corrosion of metal welding joint part | |
| CN102042951A (en) | Method for measuring corrosion of welded pipe groove by means of constant-potential electrolytic method | |
| CN106802274A (en) | Assay method of the corrosion inhibiter to Oil/Gas Pipe weld corrosion control effect | |
| CN102788745B (en) | Welding seam corrosion resistance test evaluation method | |
| Bardal et al. | Prediction of galvanic corrosion rates and distribution by means of calculation and experimental models | |
| Lu et al. | A finite element model of carbon steel welded joint corrosion under plastic strain | |
| US6960288B2 (en) | Method and device for detecting microbiologically induced corrosion | |
| CN205593902U (en) | Metal welded joint position galvanic corrosion's survey device | |
| Luo et al. | Identification of the selective corrosion existing at the seam weld of electric resistance-welded pipes | |
| CN106442682A (en) | Method of measuring critical current density in hydrogen evolution through reinforced steel bar in reinforced concrete structure | |
| CN108007853B (en) | Corrosion test device and method for grounding material in soil simulation solution | |
| Kong et al. | An experimental study of galvanic corrosion on an underwater weld joint | |
| CN105445178B (en) | One kind is for evaluating the active test fluid of surface of steel plate and method for fast measuring | |
| CN105784803A (en) | Clamp used for measuring stainless steel pipe outer surface critical point corrosion temperature | |
| Luo et al. | Effects of electromagnetic interference and crevice on corrosion of natural gas pipelines | |
| Xu et al. | The study of water-line corrosion in static and dynamically flowing electrolytes using multi-electrode sensor in combination with electrical resistance method | |
| Yang et al. | Internal current effects on localized corrosion rate measurements using coupled multielectrode array sensors | |
| CN103528943A (en) | Evaluation method of cathodic protection potential range in soil environment | |
| Werenskiold et al. | New Tool for CP inspection | |
| JPS61230042A (en) | Diagnosing method for corrosion of steel structure | |
| CN115613038B (en) | Sacrificial anode performance detection method and device | |
| Wiggle et al. | A Rapid Method to Predict the Effectiveness of Inhibited Engine Coolants in Aluminum Heat Exchangers | |
| Rocchini et al. | Electrochemical characterization of some commercial inhibitor used for acid cleaning of steam generators |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| TA01 | Transfer of patent application right | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20180110 Address after: 610041 Chengdu high tech Zone, Sichuan province sublimation Road No. 6 Applicant after: China Petroleum Engineering Construction Co Ltd Address before: 610041 Chengdu high tech Zone, Sichuan province sublimation Road No. 6 Applicant before: Engineering Design Co., Ltd., China Petroleum Group |
|
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20170606 |