GOST 9940-81

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  ГОСТ 9940-81

GOST 9940−81 seamless hot deformed Tubes made of corrosion-resistant steel. Technical specifications (Changes No. 1−4)

GOST 9940−81

Group В62

INTERSTATE STANDARD

SEAMLESS HOT DEFORMED TUBES MADE OF CORROSION-RESISTANT STEEL

Specifications

Seamless hot deformed tubes made of corrosion resistant steel. Specification

ISS 23.040.10
OKP 31 500

Date of introduction 1983−01−01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of ferrous metallurgy of the USSR

DEVELOPERS

V. P. Sokurenko (supervisor), L. G. Kovalev, V. N. Rivne, G. A. Gorovenko

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from 20.07.81 G. N 3445

Change No. 4 adopted by the Interstate Council for standardization, Metrology and certification (Protocol No. 17 dated 22.06.2000)

The adoption of the changes voted:

3. REPLACE GOST 9940−72

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

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

6. EDITION (February 2007) with Amendments No. 1, 2, 3, 4, approved in June 1987, June 1988, August 1988, April 2001 (IUS 11−87, 9−88, 12−88, 7−2001)


This standard applies to seamless hot tubes of corrosion-resistant steel for General purposes.

(Changed edition, Rev. N 3).

1. ASSORTMENT

1.1. Pipe manufactured by outside diameter and wall thickness dimensions that are listed in the table.1.

Table 1

Notes:

1. Pipes from steel 08KH17T, 15KH28, 12X17, 10X17H13M2T produce a diameter of 219 mm; steel grades 08KH17N15M3T — diameter 140 mm, the size 159х9 mm; steel grade 10Х23Н18 — diameter 168 mm, of steel grades 08KH18N12B, 08KH22N6T, 08KH20N14S2 — of a diameter not exceeding 108 mm.

2. By agreement with the consumer allowed to manufacture pipes with dimensions not listed in table.1.

3. Weight of 1 m pipe, kg, is calculated by the formula

,

where is the nominal outside diameter, mm;

 — nominal wall thickness, mm;

 — density of metal, g/cm, depending on the steel grade in accordance with table.3.

4. Pipes with diameter from 76 to 95 mm with a wall thickness of 3.5−4.0 mm, diameter from 133 to 152 mm with a wall thickness of 4.0 mm to 5.5 mm, with a diameter of less than 76 mm will be manufactured after the development of the equipment.

1.2. The length of the pipe manufacture:

measuring length within off-gage, but not less than indicated in the table.1 with maximum deviation in length +15 mm; upon agreement between the manufacturer and the consumer, it is possible to manufacture the measuring pipe lengths less than indicated in the table.1;

dimensional length, measuring length with an allowance for each cut to 5 mm and with maximum deviation over the entire length +15 mm the Minimum multiple length — 300 mm;

limited length within dimensional with maximum deviation in length ±500 mm;

random length from 1,5 to 10 m; in agreement with the consumer it is allowed manufacture of pipes longer than 10 m.

(Changed edition, Rev. N 1).

1.3. The party of pipes of random length may be no more than 15% of the pipes length from 0.75 to 1.5 m.

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

Table 2

1.5. Ovality shall not withdraw the pipe diameter for maximum deviations.

1.6. The pipe curvature of any segment with a length of 1 m must not exceed:

1.5 mm — wall thickness up to 10 mm, inclusive;

2 mm with a wall thickness of from 10 to 20 mm, inclusive;

4 mm — wall thickness more than 20 mm.

1.7. The pipe ends should be square-cut and cleaned of burrs, allowed the formation of a chamfer at their removal. At the request of the consumer at the ends of the pipes with wall thickness more than 5 mm should be beveled for welding.

Examples of symbols

Pipe outer diameter 76 mm, wall thickness of 5 mm, regular accuracy of manufacturing, off-gage length of steel grade 08CR18NI10TI:

Tube 76 5 — 08KH18N10T GOST 9940−81

The same, high precision manufacturing (in), lengths of multiples of (cu) 1500 mm:

Pipe 76 in 5 to 1500 cu — 08KH18N10T GOST 9940−81

The same, regular accuracy of manufacturing, measuring length (m) 3000 mm:

Tube 76 5 3000 m — 08KH18N10T GOST 9940−81

The same, regular accuracy of manufacturing, measuring length 3000 mm with the remainder:

Tube 76 5 3000 — 08KH18N10T GOST 9940−81

The same high-precision (b) limited length (exhaust) 3000 mm:

Pipe 76 in 5 in 3000 og — 08KH18N10T GOST 9940−81

2. TECHNICAL REQUIREMENTS

2.1. Pipe manufactured in accordance with the requirements of this standard and technical regulations approved in the prescribed manner, of the steel grades listed in table.3, with the chemical composition according to GOST 5632, micro rare earth metals.

The sulfur content in steel, intended for the manufacture of pipes to be welded that is specified in the order, shall not exceed 0.020%.

Pipes are produced heat-treated or without heat treatment in accordance with the order.

(Changed edition, Rev. N 1, 4).

2.2. Mechanical properties of pipes shall be as specified in table.3.

Table 3

Notes:

1. For pipes with a ratio equal to or less than 8, of steel grades 04KH18N10, 08KH20N14S2, 10X17H13M2T, 08KH18N12T, 10Х23Н18, 08H18N10, 08CR18NI10TI, 08KH17N15M3T, 12X18H10T, 12Х18Н12Т, 12H18N9, 17H18N9, 08KH22N6T allowed the temporary reduction of tear resistance of 19.6 N/mm(kgf 2/mm).

2. At the request of the consumer for tubes of steel grades 12X18H10T, 12Х18Н12Т, 08KH18N10T carried out to determine the yield stress.

3. The yield strength for steel of grade 12KH18N10T must be at least 216,0 N/mm(22 kgf/mm).

4. The norm of yield strength for steel grades 08KH18N10T 12Х18Н12Т and it is determined by agreement between manufacturer and consumer.


(Changed edition, Rev. N 1, 2, 3, 4).

2.3. At the request of the consumer pipe shall withstand a tensile test at a temperature of 623 K (350 °C).

Rules of temporary rupture strength and the yield strength determined by agreement between manufacturer and consumer.

(Changed edition, Rev. N 1, 3).

2.4. On the outer and inner surfaces of pipes are not allowed slivers, flaws, sunsets, cracked. Remove defects by local sweep, continuous or local sanding, boring and turning, provided that the amount of boring, turning, or grinding the solid not display the diameter and wall thickness outside negative deviations, and the local Stripping or grinding the wall thickness outside negative deviations listed in table.2.

Without Stripping the unit allowed prisoners of war, rabiza, risk, signs of indentation scale provided that they do not take wall thickness for the negative maximum deviations.

At the request of the consumer individual slivers must be stripped.

(Changed edition, Rev. N 2).

2.5. At the customer’s request pipes are made cleaned from scale.

2.6. At customer’s request, tubes shall withstand hydraulic pressure in accordance with the requirements of GOST 3845 with allowable stress equal to 40% of the temporary tear resistance for this grade of steel.

The ability of pipe to withstand hydraulic pressure is provided by the production technology.

2.7. At the customer’s request pipes of steel grades 04KH18N10, 08KH20N14S2, 10X17H13M2T, 08KH18N12B, 10Х23Н18, 08H18N10, 08CR18NI10TI, 08KH18N12T, 08KH17N15M3T, 12X18H10T, 12Х18Н12Т, 12H18N9, 17H18N9, 08KH22N6T must withstand flattening to obtain between surfaces distance (), mm, computed by the formula

,

where is the nominal wall thickness, mm;

 — nominal external diameter, mm,

or distribution to increase the outer diameter by 10% a mandrel with the taper angle 30°; it is possible to use a mandrel with a taper angle of 6° and 12°.

2.8. At the request of the consumer that is specified in the order, pipe from steel grades 10X17H13M2T, 08KH17N15M3T, 08KH22N6T, 04KH18N10, 08H18N10, 08CR18NI10TI, 12X18H10T, 12H18N9, 08KH18N12T, 12Х18Н12Т, 08KH18N12B should be resistant against intergranular corrosion.

(Changed edition, Rev. N 4).

2.9. At the request of the consumer pipe should be monitored by ultrasound. The size of artificial defect is determined by agreement between manufacturer and consumer.

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, the same grade of steel and one form of heat treatment, as customer’s request — one of melting, and decorated by one document on quality according to GOST 10692, with the addition of: chemical composition in accordance with the document, the quality of billets.

The number of pipes in the lot shall be not more than 200 PCs.

3.2. Control surfaces, dimensions, hydraulic pressure, ultrasound is subjected to control each pipe.

3.3. For quality control from the party taken:

two tubes — tensile;

one tube — flattening or distribution;

two pipe — to intergranular corrosion.

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.

(Changed edition, Rev. N 4).

3.4. (Deleted, Rev. N 4).

4. TEST METHODS

4.1. For quality control of each selected pipe cut one sample for each test.

4.2. Inspection of the pipe surface is carried out visually.

4.3. The length of the tubes test tape according to GOST 7502.

4.4. The curvature of the pipes checked straightedge according to GOST 8026 probe in the normative documentation.

(Changed edition, Rev. N 4).

4.5. The outer diameter and ovality is controlled with a micrometer smooth MK-type according to GOST 6507, sheet clamps according to GOST 18360, 18365 GOST.

The wall thickness of the pipe is controlled by micrometer type MT according to GOST 6507.

4.6. The tensile test is carried out according to GOST 10006, GOST 19040 (at a temperature of 623 K).

The speed of the movable grip — not more than 10 mm in 1 m. allowed to exceed the test speed to 40 mm in 1 min after reaching the yield stress.

Allowed control of mechanical properties to carry out the method of hardness according to normative-technical documentation.

The differences in the evaluation of test results carried out according to GOST 10006.

(Changed edition, Rev. N 1).

4.7. Test distribution is carried out on pipes with a diameter of 146 mm inclusive wall thickness of not more than 10 mm according to GOST 8694.

(Changed edition, Rev. N 1).

4.8. Test flattening is carried out on pipes with a wall thickness of not more than 10 mm in the churchyard 8695.

When detected at clusively samples of small defects resulting from external defects permitted without Stripping, a second test sample from the same tube with pre-cleaning the surface to a depth of half of the limit deviation for wall thickness, but not more than 0,2 mm from the side on which the detected defects.

4.9. The hydraulic pressure test is carried out according to GOST 3845 with aging pipes under pressure of not less than 10 s.

4.9.1. Instead of the hydraulic pressure test is allowed to carry out inspection of each pipe by nondestructive methods according to GOST 17410 and normative-technical documentation 01.01.90.

(Added, Rev. N 1).

4.10. Ultrasonic testing is carried out according to GOST 17410 and normative-technical documentation.

4.11. Test the resistance against intergranular corrosion is carried out by methods AM or AMU according to GOST 6032. In case of disagreement in evaluation of the results of the test carried out by AM.

By agreement between manufacturer and user test the resistance against intergranular corrosion of steels 08KH18N10T and 12KH18N10T grades may be performed by the method of PT according to GOST 9.914. In case of disagreement in evaluation of the results of the test carried out by AM according to GOST 6032.

(Changed edition, Rev. N 4).

5. MARKING, PACKAGING, TRANSPORTATION AND STORAGE

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