ALL-UNION SCIENTIFIC RESEARCH AND DESIGN AND TECHNOLOGY INSTITUTE
EQUIPMENT FOR OIL REFINING AND PETROCHEMICAL INDUSTRY

INSTRUCTIONS
to determine the corrosion rate of the metal of the walls of the hulls
vessels and pipelines at the enterprises of M inneftekhimprom
the USSR

Volgograd - 1983

PURPOSE AND GENERAL PROVISIONS

1.1. This instruction is intended to determine the actual rate of corrosion of the metal of the walls of vessels and pipelines, operated at the enterprises of the USSR Minneftekhimprom, in order to establish the frequency of their technical examination in accordance with the requirements of the current rules and regulations.

1.3. If it is impossible or difficult to apply the methods set forth in paragraph 1, the corrosion rate is determined approximately by witness samples or by an assessment of the corrosivity of the medium in relation to a given metal using corrosion probes.

1.4. Determination of the corrosion rate is carried out for each vessel and pipeline of the process unit, line, workshop. For a group of vessels or pipelines operating at a given process plant, line, shop in the same environment under the same operating conditions and material design, the corrosion rate is determined by the selected representative object.

1.5. The rate of corrosion of the metal of the walls of the body of vessels and pipelines is subject to clarification in each case of a significant change in the conditions of their operation (working medium, temperature, pressure) affecting the corrosive activity of the working medium, or in the case of a change in material design.

1.6. At each enterprise, the owner of the vessels, a list of vessels is compiled and approved by the chief engineer, indicating the corrosion rate of the body metal. Information on the corrosion rate of pipelines is entered in the pipeline passport.

If special types of corrosion damage are identified, such as corrosion cracking, intergranular corrosion or delamination along the wall thickness, information about this is also entered in the passport of the vessel or pipeline, and issues of further operation or repair of vessels and pipelines with such damage should be agreed with a specialized organization.

1.7. Control of the rate of corrosion of the metal of the walls of the vessels is carried out during each major overhaul, but not less than the established frequency of technical examinations of the vessels. In pipelines, the corrosion rate is monitored in each revision.

2. DETERMINATION OF THE CORROSION RATE FROM ACTUAL WALL THICKNESS MEASUREMENTS

2.1. The results of periodic measurements of the wall thickness of a vessel or pipeline serve as the basis for determining the metal corrosion rate under operating conditions.

2.2. Wall thickness measurements are made by non-destructive testing methods or by drilling and measuring the wall thickness with a measuring tool. Preference should be given to ultrasonic thickness measurement.

2.3. If the results of measuring the wall thickness by non-destructive testing methods are in doubt, then the measurement should be made by through drilling.

2.4. On vessels and pipelines operating in media that cause intergranular corrosion or stress corrosion cracking, through drillings, followed by their sealing by arc welding, are not allowed.

2.5. The place and method of measuring the wall thickness of a vessel or pipeline is determined by the results of their technical examination by technical supervision services, taking into account the characteristics of corrosion damage in various parts of vessels and pipelines.

2.6. The locations of the measurement points, the method of measurement and the results of measurements must be drawn up in the corrosion chart for the vessel or pipeline and kept in the passport (see maps and).

2.7. The calculation of the corrosion rate of the walls of vessels and pipelines is based on at least two measurements of the wall thickness according to the formula

Pe - corrosion rate in the controlled part of the vessel or pipeline under operating conditions, mm/year;

Δ S- difference in wall thicknesses at points for the period of control measurements, mm, indices 1, 2, ...,ndenote numbers of control points;

Te - operating time between control measurements, days;

n- the number of measurement control points (at least three) for each part of the vessel or for pipeline elements (pipes, bends, transitions).

Control points are selected in parts of vessels or pipeline elements that are most susceptible to corrosive wear.

2.8. The corrosion rate of a vessel or pipeline is taken to be the highest of the obtained values ​​of the corrosion rate for each part of the vessel or pipeline element.

3. DETERMINATION OF THE ID AND RATE OF CORROSION OF METAL FROM WITNESS SAMPLES

3.1. In the absence of operating experience (during the development of a new technological process) and the absence of the necessary data on thickness measurement (short service life of the vessels, inaccessibility of the object for inspection and measurements), the rate and type of corrosion is determined on the basis of testing witness samples from metal identical to the metal of the object.

3.2. The number of witness samples (at least three) at each installation point, their dimensions, installation location, as well as the program and methodology for testing are determined by the technical supervision service, the corrosion group (laboratory), depending on the design of the object, the composition of the working environment and operating conditions in individual elements of the object.

3.3. When developing a methodology for testing specimens-witnesses, it is necessary to be guided by paragraph., , , of this manual.

3.4. If it is necessary to determine the tendency of the metal of an object to intergranular corrosion or corrosion cracking, when developing a methodology and evaluating the test results of witness samples, the following technical documentation should be followed:

As electrodes in sensors of the resistometric type, a wire of 1–2 mm is used from materials for which it is necessary to check the corrosion resistance.

Rice. 1. Sluice chamber with probe for gravimetric corrosion testing.

Rice. 2. Sensors for determining the corrosive aggressiveness of the medium (A - polarizing, B - resistometric)

Cylindrical samples are used as electrodes in polarization type sensors.Æ 3 - 5 mm and up to 50 mm long, as well as plate samples collected in a package so that the electrode poles in the plates alternate in pairs, and the total area of ​​the positive electrodes is equal to the area of ​​the negative electrodes.

To obtain comparable results of the metal corrosion rate on the operating equipment and on the samples, their surface must have the same roughness. The roughness characteristic of rolled steel can be approximately achieved by reverse shot blasting or short-term etching of specimens in aqua regia (I part HNO 3 + 3 parts HCl). Sharp edges on specimens should be slightly blunted.

Before carrying out corrosion tests, it is necessary to have the following information about the material of the samples:

Grade of material according to standards or specifications;

Billet assortment (sheet, pipe, bar, etc.);

Chemical composition;

Material condition (degree of deformation and heat treatment modes);

microstructure;

The results of standard test methods (for mechanical properties, for corrosion resistance - for example, at the IWC according toGOST 6032-75) *.

_____________

* These indicators are determined if necessary.

When testing welded samples, you must additionally know:

Welding method;

Mark of welding materials;

Characteristics of technological operations;

The chemical composition of the weld metal.

For the manufacture of samples, a cutting chart should be drawn up, which indicates the locatione and the orientation of the sample relative to the workpiece and the texture of the rolled product, the direction and sequence of the welds, the numbers of the samples.

Specimens for gravimetric corrosion testing are marked by branding or inscription with an electric pencil of symbols:

From one edge of the sample, a symbol of the material grade is applied;

On the other side - the serial number of the sample.

Make sure that the valve is securely closed;

Carefully unscrew the probe cover and remove it together with the stem;

Install the sensor or sample cassette on the stem, screwing it in tightly with an interference fit (because the cassette can unscrew from the stem under vibration conditions). Remove the insulating cover from the cassette with a control card, which indicates the installation location, cassette number, immersion depth, and note the time the probe was installed. Install a mark on the rod indicating the location of the sample plane in the cassette.

Insert the cassette into the lock chamber, and close the chamber with a lid;

Carefully open the valve and slowly fill the lock chamber with the working medium. Make sure that there are no leaks in the seals of the cover and stuffing box;

Insert the probe into the working space of the apparatus or the pipeline, orienting the plane of the samples in the cassette along the flow (along the mark) and fix the rod in the required position (with a wire if there is no locking device in the probe);

During the holding of the samples, the probes are periodically checked for the absence of leaks in the seal of the cover and stuffing box, the preservation of the orientation of the samples relative to the working flow;

At the end of the specified exposure time of the samples, the cassette with samples is transferred to the lock chamber. Transfer the stem to its original position smoothly, counteracting the pressure of the medium, release the stem only after making sure that it stands on the stop. In this case, the operator should be somewhat away from the direction of movement of the rod;

Close the latch. Products, the working temperature of which poses a risk of burns for the operator, must be cooled in the lock chamber to 30 - 40 ° C;

Carefully unscrew the lock chamber cover by 0.5 - 1.5 turns and relieve pressure;

Drain the product from the lock chamber into a special canister, remove the sample cassette and pack.

Make a note on the control card about the time the cassette was removed from the workspace. Install the cover on the gateway body;

Samples in cassettes should be immediately transferred to the laboratory for processing, and the data of the control card should be entered in the “4H” card.

Corrosion measurements with sensors of the resistometric or polarization type are carried out using special electrical measuring instruments - corrosion meters according to the methods attached to these instruments.

Immediately upon completion of corrosion testing, it is necessary to disassemble the cassette and pre-wash the elements of the cassette and samples from resinous and moistened loose corrosion deposits.

Method for removing corrosion productsfrom the surface of the samples depends on their composition and properties:

Loose corrosion products with poor adhesion are removed with a hair brush, wooden spatula or soft rubber band;

Dense deposits with poor adhesion are removed with a released blade (the hardness of the blade should be lower than the hardness of the sample) by smoothing “towards itself” at a slight angle to the sample surface, followed by surface treatment with a soft rubber band;

Brittle films of corrosion products are removed by chipping by lightly tapping the sample on a hard object, followed by processing with a soft rubber band;

Brittle films of corrosion products with good adhesion (for example, sulfide scale) are removed using chemical or electrochemical etching methods (see RTM 26-01-21-68 "Guiding technical material. Methods for corrosion testing of metallic materials", section 6).

If resinous deposits are present in corrosion products, it is advisable to alternate between mechanical cleaning or chemical etching of samples with washing them in a solvent.

Data on the nature of deposits should be noted in the "4H" map.

If necessary, corrosion products are collected for analysis in glass tubes with a stopper.

Upon completion of removal from the surface of the samples of corrosion products, the samples are degreased and dried as in p.

Weighing samples after drying is carried out on the same analytical balance as in p. with an accuracy of 2 × 10 -4 g. Weighing results (m 2 ) are entered in the "4H" card.

d) Closing the gateway and removing the cassette

Rice. 3. The sequence of operations when working with a corrosion probe:

1 - working pipeline; 2 - mortise pipe; 3 - valve; 4 - lock chamber; 5 - camera cover; 6 - stock; 7 - cassette with samples.

Corrosion ratematerial determined by the resistometric method is calculated by the formula:

(4.4)

where Pr is the corrosion rate of the material, mm/year;

a- calibration factor of the measuring range in the corrosion gauge;

d- initial diameter of the wire sample, mm;

(N 2 - N 1 ) - number of divisions of the scale, instrument scale between two measurements;

(t 2 - t 1 ) is the time between two measurements, days.

The corrosion rate of the material, determined by the method of polarization resistance, is calculated by the formula:

(4.5)

where Pp is the corrosion rate of the material, mm/year;

To- constant of the sensor of the polarization type, taking into account the electromotive force of the electrochemical corrosion process, the area and geometry of the sensor electrodes and the coefficients of dimension;

Rn - polarization resistance of the sensor in an aggressive environment, measured by a corrosion meter, Ohm.

ALL-UNION SCIENTIFIC RESEARCH AND DESIGN AND TECHNOLOGY INSTITUTE
EQUIPMENT FOR OIL REFINING AND PETROCHEMICAL INDUSTRY

INSTRUCTIONS
to determine the corrosion rate of the metal of the walls of the hulls
vessels and pipelines at the enterprises of M inneftekhimprom
the USSR

Volgograd - 1983

PURPOSE AND GENERAL PROVISIONS

1.1. This instruction is intended to determine the actual rate of corrosion of the metal of the walls of vessels and pipelines, operated at the enterprises of the USSR Minneftekhimprom, in order to establish the frequency of their technical examination in accordance with the requirements of the current rules and regulations.

1.3. If it is impossible or difficult to apply the methods set forth in paragraph 1, the corrosion rate is determined approximately by witness samples or by an assessment of the corrosivity of the medium in relation to a given metal using corrosion probes.

1.4. Determination of the corrosion rate is carried out for each vessel and pipeline of the process unit, line, workshop. For a group of vessels or pipelines operating at a given process plant, line, shop in the same environment under the same operating conditions and material design, the corrosion rate is determined by the selected representative object.

1.5. The rate of corrosion of the metal of the walls of the body of vessels and pipelines is subject to clarification in each case of a significant change in the conditions of their operation (working medium, temperature, pressure) affecting the corrosive activity of the working medium, or in the case of a change in material design.

1.6. At each enterprise, the owner of the vessels, a list of vessels is compiled and approved by the chief engineer, indicating the corrosion rate of the body metal. Information on the corrosion rate of pipelines is entered in the pipeline passport.

If special types of corrosion damage are identified, such as corrosion cracking, intergranular corrosion or delamination along the wall thickness, information about this is also entered in the passport of the vessel or pipeline, and issues of further operation or repair of vessels and pipelines with such damage should be agreed with a specialized organization.

1.7. Control of the rate of corrosion of the metal of the walls of the vessels is carried out during each major overhaul, but not less than the established frequency of technical examinations of the vessels. In pipelines, the corrosion rate is monitored in each revision.

2. DETERMINATION OF THE CORROSION RATE FROM ACTUAL WALL THICKNESS MEASUREMENTS

2.1. The results of periodic measurements of the wall thickness of a vessel or pipeline serve as the basis for determining the metal corrosion rate under operating conditions.

2.2. Wall thickness measurements are made by non-destructive testing methods or by drilling and measuring the wall thickness with a measuring tool. Preference should be given to ultrasonic thickness measurement.

2.3. If the results of measuring the wall thickness by non-destructive testing methods are in doubt, then the measurement should be made by through drilling.

2.4. On vessels and pipelines operating in media that cause intergranular corrosion or stress corrosion cracking, through drillings, followed by their sealing by arc welding, are not allowed.

2.5. The place and method of measuring the wall thickness of a vessel or pipeline is determined by the results of their technical examination by technical supervision services, taking into account the characteristics of corrosion damage in various parts of vessels and pipelines.

2.6. The locations of the measurement points, the method of measurement and the results of measurements must be drawn up in the corrosion chart for the vessel or pipeline and kept in the passport (see maps and).

2.7. The calculation of the corrosion rate of the walls of vessels and pipelines is based on at least two measurements of the wall thickness according to the formula

Pe - corrosion rate in the controlled part of the vessel or pipeline under operating conditions, mm/year;

Δ S- difference in wall thicknesses at points for the period of control measurements, mm, indices 1, 2, ...,ndenote numbers of control points;

Te - operating time between control measurements, days;

n- the number of measurement control points (at least three) for each part of the vessel or for pipeline elements (pipes, bends, transitions).

Control points are selected in parts of vessels or pipeline elements that are most susceptible to corrosive wear.

2.8. The corrosion rate of a vessel or pipeline is taken to be the highest of the obtained values ​​of the corrosion rate for each part of the vessel or pipeline element.

3. DETERMINATION OF THE ID AND RATE OF CORROSION OF METAL FROM WITNESS SAMPLES

3.1. In the absence of operating experience (during the development of a new technological process) and the absence of the necessary data on thickness measurement (short service life of the vessels, inaccessibility of the object for inspection and measurements), the rate and type of corrosion is determined on the basis of testing witness samples from metal identical to the metal of the object.

3.2. The number of witness samples (at least three) at each installation point, their dimensions, installation location, as well as the program and methodology for testing are determined by the technical supervision service, the corrosion group (laboratory), depending on the design of the object, the composition of the working environment and operating conditions in individual elements of the object.

3.3. When developing a methodology for testing specimens-witnesses, it is necessary to be guided by paragraph., , , of this manual.

3.4. If it is necessary to determine the tendency of the metal of an object to intergranular corrosion or corrosion cracking, when developing a methodology and evaluating the test results of witness samples, the following technical documentation should be followed:

As electrodes in sensors of the resistometric type, a wire of 1–2 mm is used from materials for which it is necessary to check the corrosion resistance.

Rice. 1. Sluice chamber with probe for gravimetric corrosion testing.

Rice. 2. Sensors for determining the corrosive aggressiveness of the medium (A - polarizing, B - resistometric)

Cylindrical samples are used as electrodes in polarization type sensors.Æ 3 - 5 mm and up to 50 mm long, as well as plate samples collected in a package so that the electrode poles in the plates alternate in pairs, and the total area of ​​the positive electrodes is equal to the area of ​​the negative electrodes.

To obtain comparable results of the metal corrosion rate on the operating equipment and on the samples, their surface must have the same roughness. The roughness characteristic of rolled steel can be approximately achieved by reverse shot blasting or short-term etching of specimens in aqua regia (I part HNO 3 + 3 parts HCl). Sharp edges on specimens should be slightly blunted.

Before carrying out corrosion tests, it is necessary to have the following information about the material of the samples:

Grade of material according to standards or specifications;

Billet assortment (sheet, pipe, bar, etc.);

Chemical composition;

Material condition (degree of deformation and heat treatment modes);

microstructure;

The results of standard test methods (for mechanical properties, for corrosion resistance - for example, at the IWC according toGOST 6032-75) *.

_____________

* These indicators are determined if necessary.

When testing welded samples, you must additionally know:

Welding method;

Mark of welding materials;

Characteristics of technological operations;

The chemical composition of the weld metal.

For the manufacture of samples, a cutting chart should be drawn up, which indicates the locatione and the orientation of the sample relative to the workpiece and the texture of the rolled product, the direction and sequence of the welds, the numbers of the samples.

Specimens for gravimetric corrosion testing are marked by branding or inscription with an electric pencil of symbols:

From one edge of the sample, a symbol of the material grade is applied;

On the other side - the serial number of the sample.

Make sure that the valve is securely closed;

Carefully unscrew the probe cover and remove it together with the stem;

Install the sensor or sample cassette on the stem, screwing it in tightly with an interference fit (because the cassette can unscrew from the stem under vibration conditions). Remove the insulating cover from the cassette with a control card, which indicates the installation location, cassette number, immersion depth, and note the time the probe was installed. Install a mark on the rod indicating the location of the sample plane in the cassette.

Insert the cassette into the lock chamber, and close the chamber with a lid;

Carefully open the valve and slowly fill the lock chamber with the working medium. Make sure that there are no leaks in the seals of the cover and stuffing box;

Insert the probe into the working space of the apparatus or the pipeline, orienting the plane of the samples in the cassette along the flow (along the mark) and fix the rod in the required position (with a wire if there is no locking device in the probe);

During the holding of the samples, the probes are periodically checked for the absence of leaks in the seal of the cover and stuffing box, the preservation of the orientation of the samples relative to the working flow;

At the end of the specified exposure time of the samples, the cassette with samples is transferred to the lock chamber. Transfer the stem to its original position smoothly, counteracting the pressure of the medium, release the stem only after making sure that it stands on the stop. In this case, the operator should be somewhat away from the direction of movement of the rod;

Close the latch. Products, the working temperature of which poses a risk of burns for the operator, must be cooled in the lock chamber to 30 - 40 ° C;

Carefully unscrew the lock chamber cover by 0.5 - 1.5 turns and relieve pressure;

Drain the product from the lock chamber into a special canister, remove the sample cassette and pack.

Make a note on the control card about the time the cassette was removed from the workspace. Install the cover on the gateway body;

Samples in cassettes should be immediately transferred to the laboratory for processing, and the data of the control card should be entered in the “4H” card.

Corrosion measurements with sensors of the resistometric or polarization type are carried out using special electrical measuring instruments - corrosion meters according to the methods attached to these instruments.

Immediately upon completion of corrosion testing, it is necessary to disassemble the cassette and pre-wash the elements of the cassette and samples from resinous and moistened loose corrosion deposits.

Method for removing corrosion productsfrom the surface of the samples depends on their composition and properties:

Loose corrosion products with poor adhesion are removed with a hair brush, wooden spatula or soft rubber band;

Dense deposits with poor adhesion are removed with a released blade (the hardness of the blade should be lower than the hardness of the sample) by smoothing “towards itself” at a slight angle to the sample surface, followed by surface treatment with a soft rubber band;

Brittle films of corrosion products are removed by chipping by lightly tapping the sample on a hard object, followed by processing with a soft rubber band;

Brittle films of corrosion products with good adhesion (for example, sulfide scale) are removed using chemical or electrochemical etching methods (see RTM 26-01-21-68 "Guiding technical material. Methods for corrosion testing of metallic materials", section 6).

If resinous deposits are present in corrosion products, it is advisable to alternate between mechanical cleaning or chemical etching of samples with washing them in a solvent.

Data on the nature of deposits should be noted in the "4H" map.

If necessary, corrosion products are collected for analysis in glass tubes with a stopper.

Upon completion of removal from the surface of the samples of corrosion products, the samples are degreased and dried as in p.

Weighing samples after drying is carried out on the same analytical balance as in p. with an accuracy of 2 × 10 -4 g. Weighing results (m 2 ) are entered in the "4H" card.

d) Closing the gateway and removing the cassette

Rice. 3. The sequence of operations when working with a corrosion probe:

1 - working pipeline; 2 - mortise pipe; 3 - valve; 4 - lock chamber; 5 - camera cover; 6 - stock; 7 - cassette with samples.

Corrosion ratematerial determined by the resistometric method is calculated by the formula:

(4.4)

where Pr is the corrosion rate of the material, mm/year;

a- calibration factor of the measuring range in the corrosion gauge;

d- initial diameter of the wire sample, mm;

(N 2 - N 1 ) - number of divisions of the scale, instrument scale between two measurements;

(t 2 - t 1 ) is the time between two measurements, days.

The corrosion rate of the material, determined by the method of polarization resistance, is calculated by the formula:

(4.5)

where Pp is the corrosion rate of the material, mm/year;

To- constant of the sensor of the polarization type, taking into account the electromotive force of the electrochemical corrosion process, the area and geometry of the sensor electrodes and the coefficients of dimension;

Rn - polarization resistance of the sensor in an aggressive environment, measured by a corrosion meter, Ohm.

INDUSTRY STANDARD

By order of the Ministry of November 30, 1984 No. 298-65, the deadline for introduction was set from January 1, 1986.

This standard establishes the procedure for collecting, recording and analyzing information on corrosion damage to aircraft and helicopters (hereinafter referred to as products) in order to create and implement measures that increase the corrosion resistance and reliability of products.

Repair.

1.2. Sources of information are:

Aircraft fault record cards;

Reports (acts) on the generalization of experience in the operation of products by research organizations of the customer;

Generalized reports on the study of the technical condition of products in operation, including abroad;

Degree of corrosion (depth, area);

Suspected cause of corrosion;

Corrosion elimination methods;

The effectiveness of measures to eliminate corrosion;

Operating time of the product in flight hours, cycles of operation and calendar service life from the beginning of operation and operating time after the previous control of the corrosion state.

1.4. Work on the detection of corrosion damage and their elimination during operation at the maintenance stage should be carried out in accordance with the "Manual for technical operation" and "Maintenance schedule", if necessary, supplemented by "Cards for monitoring corrosion damage", which are illustrative material for technological maps.

An example of the design of the "Cards for the control of corrosion damage" is given in the recommended Appendix 1.

The number of the "Card of control of corrosion damage" consists of the number of the system and subsystem according to GOST 18675-79 and the serial number. The designation of the zone, subzone and section is made in accordance with OST 1 00264-78.

1.5. The “Corrosion damage control charts” list structural elements whose corrosion damages are classified as significant defects that affect the safety of operation and service life, and critical defects, in the presence of which operation is unacceptable, and requiring increased attention during inspections.

The need to develop "Cards for the control of corrosion damage" and include them in the operational documentation is determined by the joint decision of the developer and the customer.

1.6. The detected corrosion damage is documented by the “Aircraft Fault Accounting Card”.

In the column "External manifestation", if there is a "Card for the control of corrosion damage", its number is indicated.

1.7. Work on the study of the technical condition of products, including their corrosion state, is carried out in accordance with the "Directive plan for increasing the resource" and the "Design supervision plan" according to the relevant schedule and program, mainly on products operated in various climatic conditions with advanced operating time (calendar service life).

1.8. The study of the corrosion state of products is carried out by a group of specialists from the enterprise-developer of the product, representatives of research institutes (RI) of customers, representatives of the parent enterprise for materials and anti-corrosion protection, representatives of the aircraft repair enterprise and representatives of the manufacturer.

1.9. Based on the results of the work, an “Act of the study of the corrosion state of the product” is drawn up, which is a section of the “Act of the study of the technical condition of the product”.

The execution of the "Act of the study of the corrosion state of the product" is given in Appendix 2.

The execution of the "Action Plan for the Elimination and Prevention of Corrosion Damage to the Product" is given in Appendix 3.

It is allowed to draw it up in the section "Action plan for the product as a whole."

1.10. Based on the available information on corrosion damage classified as significant and critical defects, the developer enterprise, in agreement with the customer, develops "Corrosion damage records" given in Appendix 4, which are illustrated material for the "Repair Manual" and sends them to the repair enterprise to fill.

The company-developer receives copies of the completed "Cards of accounting for corrosion damage" from the repair company along with a statistical report.

1.11. The repair company for a newly discovered corrosion damage, which can be classified as significant or critical defects, draws up a technical solution request sheet, in which a description of the corrosion damage must be carried out in accordance with paragraph 1.3.

1.12. The developer, together with the customer, makes a decision on the request and determines the need to enter a defect in the "Corrosion Injury Control Card" for operation and the "Corrosion Injury Record Card" for the repair company, by introducing the appropriate additions to the "Technical Operation Manual" and "Repair Manual".

2. ANALYSIS OF INFORMATION ON CORROSION DEFECTS OF PRODUCTS

2.1. When analyzing information on corrosion damage to products by the reliability service of the repair enterprise of the customer, developer, serial plant, the following are revealed:

The number of corrosion-affected assembly units (parts) of a given name in the fleet of products with a given operating time by systems, assembly units (parts), the corrosion damage of which is of a massive nature with a given operating time (service life) of products;

Operating time or service life before corrosion;

Influence of climatic conditions on corrosion resistance;

Design, technological, production, repair, operational deficiencies, which are the main causes of corrosion damage;

Structural elements on which types of corrosion are found (corrosion cracking, intergranular corrosion, exfoliating corrosion, etc.), which can lead to significant and critical defects;

Zones in which corrosion damage to structural elements most often occurs;

Structural elements, the dimensions of corrosion damage of which exceed the allowable repair dimensions of parts;

The complexity of eliminating corrosion.

2.2. Based on the analysis of the information received on corrosion damage to products, the developer, together with the customer's representative at the developer and the manufacturer, develop a report on the corrosion state of products, followed by its approval with the parent organization for materials and corrosion protection and sends it to the customer's research institute and other interested organizations.

The report should reflect:

Evaluation of the effectiveness of the anti-corrosion protection of the product;

Determining the effectiveness of the improvements carried out;

Determination of the effectiveness of routine and repair work in terms of volume and frequency;

Development of measures to eliminate and prevent corrosion of assembly units (parts) that determine flight safety, the size of corrosion damage of which exceeds the allowable repair dimensions of parts;

Development of measures to further improve the design in the field of anti-corrosion protection and increase its level;

Development of measures to eliminate operational and repair deficiencies to prevent corrosion during operation;

Clarification of resources and service life of products, the frequency of their maintenance.

APPENDIX 1

EXAMPLE OF DESIGNING A CORROSION DAMAGE CONTROL CHART

APPENDIX 2

Mandatory

REGISTRATION OF THE "ACT OF RESEARCH OF THE CORROSIVE STATE OF THE PRODUCT"

APPENDIX 3

Mandatory

FORMULATION OF A PLAN OF ACTION TO REMOVE AND PREVENT CORROSION DEFECTS OF PRODUCTS

APPROVE

Chief designer of the enterprise-developer __________________

________________ / ___________ /

"____" ________________ 19 ___

ACTION PLAN TO REMOVE AND PREVENT CORROSION DEFECTS OF THE PRODUCT __________

APPENDIX 4

Mandatory

REGISTRATION OF THE CORROSION DAMAGE CARD

Navigation maps must strictly correspond to the situation on the ground. Changes on the terrain occur all the time: new facilities are being built and installed on the coast, old facilities are being destroyed, new underwater obstacles are appearing, fairways are being cleared and cleared of dangers, etc.

To keep the map up to date, i.e., to bring it into line with the locality, it is necessary to correct the map by applying to it the changes that have taken place in the locality. Card corrections can be done in various ways: compose a new original card and print a new edition from it, or correct the original card and print a edition from it, or correct each copy of existing cards by hand.

Therefore, all corrections, depending on the volume and method, are divided into a new edition, major proofreading and minor proofreading.

New editions are issued in the event that the volume of changes in the terrain requires the correction of 50% or more of the cartographic load of this map.

With the release of a new edition of the card, all previously issued editions of this card are considered obsolete and unsuitable for use.

A new edition of a chart is usually officially notified in a Notice to Mariners.

Big map correction is performed when the volume of changes that have occurred on the ground, although it requires corrections of less than 50% of the cartographic load of the map, but it is not advisable to make them manually: the corrections are significant, and if they are made by hand, the map will be difficult to read and unsuitable for use.

Major corrections include corrections corresponding to the following changes in the terrain: moving noticeable coastal objects and setting new ones, changing the characteristics of lighthouses and illuminated signs, new data on depths (based on the results of later soundings), changing the coastline (building a pier, erosion of the coast, etc.). d.).

Major proofreading is performed on one of the maps, which, after its correction, is the original. The publisher's original is photographed, a printing plate is made and a circulation is printed. The new edition and major proofreading are carried out by cartographers.

Minor map corrections- correction of individual elements of the map, made by hand without compromising the clarity of the map.

Small corrections are made by the navigators directly on the ships.

Materials for minor proofreading are:

notices to seafarers;

Radio navigation warnings (NAVIP);

Additions to sailing directions and other sailing manuals;

Consolidated corrections to the sailing manuals.

On ships, it is recommended to keep a special journal for correcting charts and manuals. All charts and manuals must be corrected immediately upon receipt of the Notice and, in any case, before sailing. If for some reason this was not done in a timely manner, then when using the chart during the voyage, it is necessary to check whether there are Notices for this chart in the correction log or in the catalog of charts, and if there are any, make corrections.

Corrections of a permanent nature are made in red ink or red ink in small print in compliance with the conventions; corrections of a temporary or presumptive nature are made in pencil. With a large amount of text proofreading, it is more convenient to retype the text of the Notice to Mariners on a typewriter and paste it in. appropriate place in the book.

Sometimes it is possible to cut out the proof text from the Notice to Mariners and paste it into the book. Correction of maps must be started from the last Notice, since subsequent ones may annul the information contained in the previous ones. If the Notice contains references to several maps, then the correction should be started with maps of the largest scale, as this will facilitate subsequent corrections on small-scale maps; sometimes on the latter it is impossible to make corrections with sufficient clarity at all.

A note about the correction, indicating the number and date of the Notice, is made at the bottom under the frame of the map, on the left side, in red ink or ink and signed by the person who made the corrections on the map.

On those vessels of lake and coastal navigation, on which systematic correction of charts and manuals is not always possible due to specific navigation conditions, charts and manuals should be handed over for correction to the navigation chambers.

• Claim for the replacement of goods of inadequate quality or a refund of money paid for the goods (sample form). Corrosion map of the vessel (ITNE-93). Document's name