GOST 11068-81

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  ГОСТ 11068-81

GOST 11068−81 electrically tubes made of corrosion-resistant steel. Specifications (with Amendments No. 1, 2, adjusted)

GOST 11068−81

Group В62

INTERSTATE STANDARD

ELECTRICALLY TUBES MADE OF CORROSION-RESISTANT STEEL

Specifications

Electrically welded pipes made of corrosion resistant steel. Specifications

ISS 23.040.10
OKP 13 7100

Date of introduction 1983−01−01

Resolution of the USSR State Committee for standards from October 20, 1981 N 4629 date of introduction is established 01.01.83

Limitation of actions taken by Protocol No. 2−92 of the Interstate Council for standardization, Metrology and certification (ICS 2−93)

REPLACE GOST 11068−64

Change No. 2 adopted by the Interstate Council for standardization, Metrology and certification (Protocol No. 10 dated 03.10.96)

The adoption of the changes voted:

EDITION (August 2004) with Changes No. 1, 2 approved in June 1987-April 1999 (IUS 11−87, 7−99)

AMENDED, published in IMS No. 5, 2005

An amendment made by the manufacturer of the database

This standard applies to electrically welded pipes of corrosion-resistant (stainless) steels intended for the manufacture of pipes and various designs.

(Changed edition, Rev. N 1, 2).

1. ASSORTMENT

1.1. The pipe dimensions shall be as specified in table.1.

Table 1

Notes:

1. The pipe sizes in brackets in the design of new objects is not recommended.

2. Theoretical weight of 1 m pipe (kg) is calculated according to the formula

,

where is the nominal outside diameter of pipe, mm;

 — the nominal wall thickness of pipe, mm;

 — density of metal, g/cm, depending on the steel grade:

08KH18N10T, 10KH18N10T, 12X18H10T, 03KH18N10T, 08X18H10 — 7,9;

08KH21N6M2T — 7,85;

10X17H13M2T, 10H17N13M3T, 03Х17Н13М2Т, 03KH17N14M3 — 8,0;

08KH22N6T — 7,6;

06HN28MDT — of 7.95.

04KH17T, 08KH18T1 — OF 7.72.

3. The pipes from steel grades 08KH18T1 and 04KH17T manufactured with wall thickness up to 2.0 mm.

4. By agreement with the consumer pipe can be manufactured: intermediate dimensions with tolerances on diameter and wall thickness of the surrounding larger sizes; corrosion-resistant steels other brands; with an offset or unilateral tolerance for the external diameter. The magnitude of the field offset or unilateral tolerance must not exceed the amount of bilateral deviations.

(Changed edition, Rev. N 1, 2).

1.2. The length of the pipe should produce:

lengths — from 5 to 9 m:

gauge length with the residue not more than 10% (by weight) pipes of random length;

multiple lengths up to 9 m and with an allowance for each cut to 5 mm (if the other stock is not specified in the order), which is included in every multiple of the length;

multiple lengths with the remainder not more than 10% (by weight) pipes of random length;

random length from 1,5 to 9 m.

1.3. Maximum deviations along the length of the pipe dimensional and multiple lengths shall not exceed +15 mm.

1.2, 1.3. (Changed edition, Rev. N 1).

1.4. Limit deviations for outer diameter and wall thickness are shown in table.2.

Table 2

At the request of the consumer pipe sizes 38х1,5 and 43х1,5 mm produce extreme deviations in outside diameter mm.

1.4. (Changed edition, Rev. N 1, 2).

1.5. Ovality and raznoshennoy pipes should not display the pipe sizes for maximum deviations accordingly, the diameter and wall thickness.

1.6. The tolerance on the straightness of the tubes shall not exceed 1.5 mm per 1 m length.

Examples of symbols

Pipe outer diameter 25 mm and wall thickness 2 mm, random length, of steel grade 08CR18NI10TI:

Pipe 25x2−08KH18N10T GOST 11068−81

Same with length a multiple of 2000 mm:

Pipe 25х2х2000 cu-08KH18N10T GOST 11068−81

The same lengths of 6000 mm:

Pipe 25х2х6000−08KH18N10T GOST 11068−81

The same manufacturing high precision:

Pipe 25Пх2Пх6000−08KH18N10T GOST 11068−81

For heat treated pipe, after the pipe is stamped with the letter T.

2. TECHNICAL REQUIREMENTS

2.1. Pipe manufactured in accordance with the requirements of this standard for technological regulations approved in the prescribed manner, of steel grades 10KH18N10T and 04KH17T with the chemical composition given in table.3, and steel grades 08KH18N10T, 08KH18T1, 08X18H10, 12X18H10T, 10X17H13M2T, 10H17N13M3T, 08KH22N6T, 08KH21N6M2T, 06HN28MDT, 08KH17N13M2T, 03KH17N14M3, 03KH18N10T with the chemical composition according to GOST 5632−72.

Table 3

________________
* The concentration of carbon in steel, %.

Notes:

1. The deviation in the mass fraction of Nickel to minus 0.5%.

2. By agreement of the parties allowed the clarification of chemical composition of steel.

2.2. Tubes of steel grades 08CR18NI10TI, 08KH18T1, 10KH18N10T, 12X18H10T, 04KH17T produce thermally processed with the mechanical properties specified in table.4. Mechanical properties of pipes made of steel 08KH18T1 and 04KH17T for wall thickness more than 1.5 mm is established by agreement of the parties.

Table 4

2.1, 2.2. (Changed edition, Rev. N 2).

2.2.1. Tubes from other steel grades listed in clause 2.1, produce thermally processed, and at the request of the consumer without heat treatment; mechanical properties established by agreement between manufacturer and consumer.

2.2.2. By agreement with the consumer pipe can be cold and warm deformation in the line of the mill.

2.2.2. (Added, Rev. N 2).

2.3. On the surface of the pipes is not permitted lack of fusion, pores, cracks, slivers, flaws, scales, traces of Pererva.

Allowed scratches, traces of changes, risks, signs of Stripping defects, if you do not derive the thickness of the tube wall for limiting deflection and color tint resulting from heat treatment or welding.

By agreement with consumer it is permitted to supply pipes made of steel 08KH18T1 and 04KH17T with an oxide film on the surface formed by the heat treatment.

Pipes can be produced with a polished outer surface. The roughness is set by agreement with the consumer.

On the outer surface of tubes in contact with the gasket permitted areas narotra due to the technology of etching.

(Changed edition, Rev. N 2).

2.4. The height of the internal weld shall not exceed:

0.7 mm — for pipes of General purpose;

0.1 mm — for pipes, reaching for the manufacture of tubular heating elements.

At the customer’s request pipes of General purpose with nominal diameter of over 20 mm are made with the height of the Burr is not more than 0.3 mm. the transition from the weld to the pipe walls should be smooth.

2.5. The pipe ends should be square-cut and cleaned of burrs. Allowed the formation of chamfer when deburring. At the request of the customer can be manufactured pipe with a deburring and inner chamfer from one end provided the orientation of the stripped ends in the same direction.

At the customer’s request pipes are made cut in the line of the mill.

(Changed edition, Rev. N 2).

2.6. For chemical engineering, chemical industry, and at the request of the consumer for other industries heat treated tubes of steel grades 08CR18NI10TI, 10KH18N10T, 10X17H13M2T, 10H17N13M3T, 08KH22N6T, 08KH21N6M2T, 06HN28MDT must withstand the test of intercrystalline corrosion.

(Changed edition, Rev. N 1).

2.7. Tubes of steel grades 08CR18NI10TI, 10KH18N10T must withstand the test of flattening to the distance () between splosives planes in millimeters from the following formula

,

where is the nominal wall thickness of pipe, mm;

 — nominal outside diameter of pipe, mm.

At the request of the consumer for pipes with a ratio of 0.04 or more, the distance should not be more than 1/3.

Thermally treated tubes from other steel grades to withstand the test of flattening to a distance equal to ½ of the outer diameter.

Tube without heat treatment must withstand the test of flattening to a distance equal to 2/3 of the outer diameter.

2.8. At customer’s request, heat-treated pipe shall withstand the following tests:

test distribution to increase the outer diameter:

12% — for tubes from steel grades 08KH18N10T, 08KH18T1, 08X18H10, 12X18H10T, 10KH18N10T, 04KH17T, 03KH18N10T, 08KH17N13M2T, 03KH17N14M3;

6% for tubes from other steel grades.

By agreement of the parties tubes of steel grades 08KH18T1, 10KH18N10T, 12X18H10T must pass the test for the distribution of 15%;

test turn-up cuffs to obtain a width of the bent side, measured from the inner surface of the pipe, equal to 1.5 of wall thickness (test turn-up cuffs is carried out on pipes with a diameter of not less than 25 mm; angle flanging 90°);

test bend (amount of bend radius is set by agreement between manufacturer and consumer).

2.7, 2.8. (Changed edition, Rev. N 2).

2.9. At the request of the consumer, the grain size of metal of the finished pipes of steel grades and 12X18H10T 10KH18N10T should be 3−7 points.

2.10. Tubes shall withstand hydraulic test pressure 6 MPa (60 kgf/cm) or testing the weld using non-destructive methods.

At customer’s request, tubes shall withstand hydraulic pressure (a) in accordance with the requirements of GOST 3845−75, but not more than 20 MPa (200 kgf/cm). Thus the allowable stress in the pipe wall shall be equal to 40% of the temporary tear resistance.

3. ACCEPTANCE RULES

3.1. Pipes take by the parties. The party should consist of pipes of the same size in diameter and wall thickness, same steel, same heat treatment and accompanied by one document on quality in accordance with GOST 10692−80.

The number of pipes in the lot shall be not more than:

500 pieces — with the diameter up to 30 mm;

300 pieces — with a diameter of over 30 mm.

3.2. The chemical composition of the steel take on the document about the quality of the source coils.

The differences in the evaluation of the chemical composition to verify selected one pipe from the party.

3.3. Checking the surface quality and dimensions, as well as the testing of tubes by hydraulic pressure or non-destructive methods are subjected to each pipe of the party.

At the request of the consumer under the inspection of welded seams of pipes non-destructive methods to carry out additional testing of hydraulic pressure from 10 to 100% tube party.

(Changed edition, Rev. N 1).

3.4. To check the height of the inner bead selected 2% of the pipes from the party.

3.5. For tensile tests, intergranular corrosion, distribution, turn-up cuffs, bend, flattening the two tubes taken from the party. To determine the grain size selected one pipe from the party.

Determination of the yield strength of the metal is carried out at the request of the consumer.

3.6. If unsatisfactory test results of at least one of the indicators it is carried out re-tests on twice the number of pipes selected from the same batch.

The results of repeated tests apply to the entire party.

4. TEST METHODS

4.1. From each selected pipe cut one sample for each test.

4.2. Chemical analysis carried out according to GOST 12344−2003, 12346−78 GOST, GOST 12347−77,12348−78 GOST, GOST 12349−83, 12350−78 GOST, GOST 12351−2003, 12352−81 GOST, GOST 12353−78, 12354−81 GOST, GOST 12355−78, 12356−81 GOST, GOST 12365−84 or 28473−90 GOST, GOST 22536.0−87 GOST 22536.14−88.

Sampling is carried out according to GOST 7565−81.

4.3. Inspection of the pipe surface is carried out visually. The depth of the defects check adproval or other means.

4.4. The pipe sizes check:

the length — measuring GOST 7502−98;

the outer diameter and ovality — adjustable measuring caliper according to GOST 2216−84или caliper according to GOST 166−89, or micrometer according to GOST 6507−90;

deviation from straightness — straightedge according to GOST 8026−92 probe according to the normative document;

the thickness of the wall, raznoshennoy and height of the inner bead — micrometer according to GOST 6507−90 or santomera according to GOST 11358−89. Measurement of height of the inner bead is carried out at distance of 25 mm from the ends of the pipes, and the outer diameter at least 15 mm from the ends of the pipes.

It is allowed to control the length, outer diameter and wall thickness of tubes, automatic means in the normative documentation. In case of disagreement in the evaluation of the measurement results, the control is performed using the measuring instruments described above.

(Changed edition, Rev. N 1).

4.5. The grain size is determined by the base metal according to GOST 5639−82. The pipe does not experience intergranular corrosion.

4.6. Sampling and testing for intergranular corrosion is carried out according to GOST 6032−2003. In case of disagreement in the evaluation of test results carried out by the method of GOST 6032−2003 AM, except for pipes of steel grade 06HN28MDT.

(Changed edition, Rev. N 1).

4.7. The tensile test is carried out according to GOST 10006−80 on the longitudinal short sample (in the form of a strip with a seam or cut the pipe). Test speed up to yield strength should be not more than 10 mm/min, yield point is not more than 40 mm/min.

4.8. Hydraulic testing is carried out according to GOST 3845−75 with time under pressure of not less than 5 s.

4.9. Test distribution is carried out according to GOST 8694−75 on the mandrel with a taper of 30°.

4.10. Test turn-up cuffs is carried out according to GOST 8693−80.

4.11. Test flattening is carried out according to GOST 8695−75 at the position of the weld horizontal. On customer requirement the test shall be performed at two positions of the weld: horizontal and vertical.

(Changed edition, Rev. N 2).

4.12. The bend test is carried out according to GOST 3728−78.

4.13. Non-destructive quality control of the weld carried out according to regulatory documents.

4.14. Right angle trim the ends of the pipes is not controlled and is determined by the design of the equipment for cutting pipes.

(Added, Rev. N 1).

5. MARKING, PACKAGING, TRANSPORTATION AND STORAGE

5.1. Marking, packaging, transportation and storage — by GOST 10692−80.

(Changed edition, Rev. N 1).

5.2. (Deleted, Rev. N 2).