GOST 9940-81
Group B62
INTERSTATE STANDARD
HOT-WORKED SEAMLESS PIPES FROM CORROSION-RESISTANT STEEL
Specifications
Seamless hot deformed tubes made of corrosion resistant steel. Specification
ISS 23.040.10
OKP 31 500
Introduction date 1983-01-01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of Ferrous Metallurgy of the USSR
DEVELOPERS
V.P. Sokurenko (theme leader), L.G. Kovaleva, V.N. Rovensky, G.A. Gorovenko
2. APPROVED AND INTRODUCED BY Decree of the State Committee of the USSR on Standards dated July 20, 1981 N 3445
Change N 4 adopted by the Interstate Council for Standardization, Metrology and Certification (minutes N 17 dated 06/22/2000)
Voted for the change:
State name | Name of the national standardization body | |||
The Republic of Azerbaijan | Azgosstandart | |||
Republic of Armenia | Armstate standard | |||
Republic of Belarus | State Standard of the Republic of Belarus | |||
The Republic of Kazakhstan | State Standard of the Republic of Kazakhstan | |||
Republic of Kyrgyzstan | Kyrgyzstandart | |||
The Republic of Moldova | Moldovastandard | |||
Russian Federation | Gosstandart of Russia | |||
The Republic of Tajikistan | Tajik State Standard | |||
Turkmenistan | Main State Inspectorate "Turkmenstandartlary" | |||
The Republic of Uzbekistan | Uzgosstandart | |||
Ukraine | State Standard of Ukraine | |||
3. REPLACE GOST 9940-72
4. REFERENCE REGULATIONS AND TECHNICAL DOCUMENTS
Item number |
|
5. The limitation of the validity period was removed according to protocol N 2-92 of the Interstate Council for Standardization, Metrology and Certification (IUS 2-93)
6. EDITION (February 2007) with Amendments No. 1, 2, 3, approved in June 1987, June 1988, August 1988, April 2001 (IUS 11-87, 9-88, 12-88, 7-2001)
This International Standard applies to seamless hot-worked stainless steel pipes for general use.
(Changed edition, Rev. N 3).
1. ASSORTMENT
1. ASSORTMENT
1.1. Pipes are made according to the outer diameter and wall thickness with the dimensions indicated in Table 1.
Table 1
Notes:
1. Pipes made of steel grades 08X17T, 15X28, 12X17, 10X17H13M2T are made with a diameter of no more than 219 mm; from steel grades 08X17H15M3T - with a diameter of not more than 140 mm, size 159x9 mm; from steel grade 10X23H18 - with a diameter of not more than 168 mm; from steel grades 08Kh18N12B, 08Kh22N6T, 08Kh20N14S2 - with a diameter of not more than 108 mm.
2. By agreement between the manufacturer and the consumer, it is allowed to manufacture pipes with dimensions not indicated in Table 1.
3. The mass of 1 m of pipes, kg, is calculated by the formula
where is the nominal outer diameter, mm;
- nominal wall thickness, mm;
- metal density, g/cm, depending on the steel grade in accordance with Table 3.
4. Pipes with a diameter of 76 to 95 mm with a wall thickness of 3.5-4.0 mm, a diameter of 133 to 152 mm with a wall thickness of 4.0-5.5 mm, a diameter of less than 76 mm will be produced after the development of the equipment.
1.2. The length of the pipe is made:
measured length - within the unmeasured, but not more than that indicated in Table 1 with a maximum deviation along the length of +15 mm; by agreement between the manufacturer and the consumer, it is allowed to manufacture measured pipes with a length exceeding that indicated in Table 1;
length, a multiple of the measured length, - within the measured length with an allowance for each cut of 5 mm and with a maximum deviation along the entire length of +15 mm. Minimum multiple length - 300 mm;
limited length - within the measured length with a maximum deviation along the length of ± 500 mm;
random length - from 1.5 to 10 m; by agreement between the manufacturer and the consumer, it is allowed to manufacture pipes with a length of more than 10 m.
1.3. In a batch of pipes of random length, no more than 15% of pipes with a length of 0.75 to 1.5 m are allowed.
1.4. Limit deviations for the outer diameter and wall thickness are shown in Table 2.
table 2
Pipe dimensions | Limit deviations for manufacturing accuracy, % |
|
high |
||
By outside diameter | ||
By wall thickness, mm: | ||
12,5 |
||
more than 8 to 20 | ||
12,5 | ||
1.5. The ovality should not lead the diameter of the pipes beyond the limit deviations.
1.6. The curvature of pipes in any section 1 m long should not exceed:
1.5 mm - with a wall thickness of up to 10 mm inclusive;
2 mm - with a wall thickness over 10 to 20 mm inclusive;
4 mm - with a wall thickness over 20 mm.
1.7. The ends of the pipes must be cut at a right angle and cleaned of burrs, chamfering is allowed when they are removed. At the request of the consumer, at the ends of pipes with a wall thickness of more than 5 mm, there must be a chamfer for welding.
Legend Examples
Pipe with an outer diameter of 76 mm, a wall thickness of 5 mm, the usual manufacturing accuracy, random length, made of steel grade 08X18H10T:
Trumpet 765 - 08X18H10T GOST 9940-81
The same, high-precision manufacturing (c), length multiple (cr) 1500 mm:
Pipe 76 in 5 in 1500 kr - 08X18H10T GOST 9940-81
The same, the usual manufacturing accuracy, measured length (m) 3000 mm:
Pipe 76 5 3000 m - 08X18H10T GOST 9940-81
The same, the usual manufacturing accuracy, measured length 3000 mm with the remainder:
Pipe 76 5 3000 - 08X18H10T GOST 9940-81
The same, high-precision manufacturing (c), limited length (og) 3000 mm:
Pipe 76 in 5 in 3000 og - 08X18H10T GOST 9940-81
2. TECHNICAL REQUIREMENTS
2.1. Pipes are manufactured in accordance with the requirements of this standard and according to the technical regulations approved in in due course, from steel of the grades indicated in Table 3, with a chemical composition according to GOST 5632, with micro-additives of rare earth metals.
The sulfur content in steel intended for the manufacture of pipes to be welded, which is indicated in the order, should 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. The mechanical properties of the pipes must correspond to those indicated in Table 3.
Table 3
steel grade | Tensile strength, N/mm (kgf/mm) | Relative extension | Density, g/cm |
at least | |||
08Х17Н15М3Т | |||
08X18H10T | |||
08X18N12B | |||
08Х18Н12Т | |||
08Х20Н14С2 | |||
10X17H13M2T | |||
12X18H10T | |||
12X18H12T | |||
Notes:
1. Для труб с соотношением равным или менее 8, из стали марок 04Х18Н10, 08Х20Н14С2, 10Х17Н13М2Т, 08Х18Н12Т, 10Х23Н18, 08Х18Н10, 08Х18Н10Т, 08Х17Н15М3Т, 12Х18Н10Т, 12Х18Н12Т, 12Х18Н9, 17Х18Н9, 08Х22Н6Т допускается снижение временного сопротивления разрыву на 19,6 Н/ mm(2 kgf/mm).
2. At the request of the consumer, for pipes made of steel grades 12X18H10T, 12X18H12T, 08X18H10T, the yield strength is determined.
3. The yield strength for steel grade 12X18H10T must be at least 216.0 N/mm (22 kgf/mm).
4. The yield strength standards for steel grades 12X18H12T and 08X18H10T are set by agreement between the manufacturer and the consumer.
(Changed edition, Rev. N 1, 2, 3, 4).
2.3. At the request of the consumer, the pipes must withstand a tensile test at a temperature of 623 K (350 ° C).
The norms of temporary tensile strength and yield strength are set by agreement between the manufacturer and the consumer.
(Changed edition, Rev. N 1, 3).
2.4. Captivity, flaws, sunsets, cracks are not allowed on the outer and inner surfaces of the pipes. It is allowed to remove defects by local cleaning, continuous or local grinding, boring and turning, provided that the value of boring, turning or continuous grinding does not take the diameter and wall thickness beyond the minus deviations, and local cleaning or grinding - the wall thickness beyond the minus deviations indicated in table 2.
Without stripping, single films, ripples, risks, traces of indentation of scale are allowed, provided that they do not take the wall thickness beyond minus limit deviations.
At the request of the consumer, individual captives must be cleaned.
(Changed edition, Rev. N 2).
2.5. At the request of the consumer, the pipes are made cleaned of scale.
2.6. At the request of the consumer, the pipes must withstand hydraulic pressure in accordance with the requirements of GOST 3845 at an allowable stress equal to 40% of the tensile strength for a given steel grade.
The ability of pipes to withstand hydraulic pressure is ensured by the production technology.
2.7. По требованию потребителя трубы из стали марок 04Х18Н10, 08Х20Н14С2, 10Х17Н13М2Т, 08Х18Н12Б, 10Х23Н18, 08Х18Н10, 08Х18Н10Т, 08Х18Н12Т, 08Х17Н15М3Т, 12Х18Н10Т, 12Х18Н12Т, 12Х18Н9, 17Х18Н9, 08Х22Н6Т должны выдерживать сплющивание до получения между поверхностями расстояния (), мм, вычисленного по формуле
where is the nominal wall thickness, mm;
- nominal outer diameter, mm,
or expansion to increase the outer diameter by 10% with a mandrel with a taper angle of 30°; it is allowed to use mandrels with a taper angle of 6° and 12°.
2.8. At the request of the consumer, which is indicated in the order, pipes made of steel grades 10X17H13M2T, 08X17H15M3T, 08X22H6T, 04X18H10, 08X18H10, 08X18H10T, 12X18H10T, 12X18H9, 08X18H12T, 12X18H12N
2.9. At the request of the consumer, the pipes must undergo ultrasonic testing. The dimensions of an artificial defect are set by agreement between the manufacturer and the consumer.
3. ACCEPTANCE RULES
3.1. Pipes are accepted in batches. The batch must consist of pipes of the same size in diameter and wall thickness, one steel grade and one type of heat treatment, and at the request of the consumer - one heat, and is issued with one quality document in accordance with GOST 10692, with the addition: chemical composition - in accordance with the document about the quality of the tubular billet.
The number of pipes in a batch should be no more than 200 pcs.
3.2. Each pipe is subjected to surface control, dimensions, hydraulic pressure, ultrasonic control.
3.3. For quality control, the following items are selected from the batch:
two pipes - for tension;
one pipe - for flattening or distribution;
two pipes - for intergranular corrosion.
If unsatisfactory test results are obtained for at least one of the indicators, repeated tests are carried out on it on a double number of pipes selected from the same batch.
The retest results apply to the entire lot.
(Changed edition, Rev. N 4).
3.4. (Deleted, Rev. N 4).
4. TEST METHODS
4.1. For quality control, one sample is cut from each selected pipe for each type of test.
4.2. Inspection of the surface of the pipes is carried out visually.
4.3. The length of the pipes is checked with a tape measure according to GOST 7502 ..
4.6. The tensile test is carried out according to GOST 10006, GOST 19040 (at a temperature of 623 K).
The speed of movement of the movable grip is no more than 10 mm per 1 min. It is allowed to exceed the test speed up to 40 mm in 1 min after reaching the yield strength.
Allowed control mechanical properties carry out by the hardness method according to the normative and technical documentation.
In case of disagreement in evaluating the results, the tests are carried out according to GOST 10006.
(Changed edition, Rev. N 1).
4.7. The expansion test is carried out on pipes with a diameter of up to 146 mm inclusive with a wall thickness of not more than 10 mm in accordance with GOST 8694.
(Changed edition, Rev. N 1).
4.8. The flattening test is carried out on pipes with a wall thickness of not more than 10 mm in accordance with GOST 8695.
If small defects are found on the flattened samples, which are the result of external defects that are allowed without stripping, the sample is retested from the same pipe with preliminary cleaning of the surface to a depth of half the maximum deviations in wall thickness, but not more than 0.2 mm from the side on which defects are found.
4.9. The hydraulic pressure test is carried out in accordance with GOST 3845 with holding pipes under pressure for at least 10 s.
4.9.1. Instead of testing with hydraulic pressure, it is allowed to inspect each pipe by non-destructive methods in accordance with GOST 17410 and regulatory and technical documentation from 01.01.90.
(Introduced additionally, Rev. N 1).
4.10. Ultrasonic testing is carried out in accordance with GOST 17410 and normative and technical documentation.
4.11. Resistance to intergranular corrosion is tested using the AM or AMU methods according to GOST 6032. In case of disagreement in the evaluation of the results, the verification is carried out by the AM method.
By agreement between the manufacturer and the consumer, it is allowed to test the resistance to intergranular corrosion of steel grades 12X18H10T and 08X18H10T by the PT method in accordance with GOST 9.914. In case of disagreement in the evaluation of the results, the verification is carried out by the AM method according to GOST 6032.
(Changed edition, Rev. N 4).
5. MARKING, PACKAGING, TRANSPORT AND STORAGE
5.1. Marking, packaging, transportation and storage - according to GOST 10692.
Electronic text of the document
prepared by Kodeks JSC and verified against:
official publication
M.: Standartinform, 2007
The stainless pipe, all the requirements for the parameters of which are stipulated by GOST, is the best choice for the installation of pipelines transporting liquid and gaseous media with high chemical aggressiveness. There is a great need for such pipelines in many industries - chemical and petrochemical, general and nuclear engineering, thermal power engineering, equipping water vessels, etc.
Requirements of GOST 9941-81
You can get acquainted with the GOST requirements for cold- and heat-formed stainless steel pipes by downloading the document in pdf format from the link below.
GOST 9941-81 Seamless cold- and heat-deformed pipes made of corrosion-resistant steel. Specifications
GOST 9941-81 specifies requirements for pipes round section which are made from general purpose. Under action this document seamless pipes produced by cold and warm deformation technology are included. GOST 9941-81 indicates that stainless pipes of this type can be produced in the range of outer diameters of 5–273 mm and with a wall thickness in the range of 0.2–22 mm.
They determine the requirements of GOST and the length of pipes made of stainless steel of this category, which can be measured, located in the range of 5–7 meters, as well as random and multiple dimensional. At the request of customers and in agreement with the manufacturer, it is allowed to manufacture such products in a wider range of lengths - 0.5–16 meters.
GOST allows the presence in the total batch of pipes of random length products, the length of which is in the following ranges:
It should be borne in mind that the number of pipes with the specified parameters cannot exceed 6% of the volume of the entire batch in which they are present.
Depending on the degree of compliance of the geometric parameters of corrosion-resistant pipes with the values specified in GOST, such products can be classified into one of three categories: ordinary, high and increased accuracy. For each of these categories, the standard specifies the maximum deviations of the wall thickness. So, for different categories of pipe rolling, GOST stipulates the following tolerances:
According to the outer diameter of round pipes made of stainless steels, the following deviations are also stipulated in GOST:
For pipes with a diameter greater than 30 mm, made of stainless steel grade 06KhN28MDT, the maximum deviation of the outer diameter is 1.2%.
Parameters of cold and heat deformed pipes
Ends stainless steel pipes, made by cold or hot deformation technology, are cut at an angle of 90 °, while burrs must be removed from the cut ends. GOST allows that chamfers can be formed on the cut ends of pipes when deburring. Moreover, on steel pipes with a wall thickness exceeding 5 mm, chamfers are often specially made at the request of the customer, allowing for more efficient and high-quality installation by welding.
The provisions of GOST for pipe-roll made of stainless steel also stipulate such a parameter as surface curvature, measured over a length segment not exceeding 100 cm. Depending on the thickness of the pipe wall and its outer diameter, this parameter should not exceed the following values:
It should be borne in mind that GOST does not specify the limit value for the curvature of the surface of stainless steel pipes if the outer diameter of such products is less than one and a half centimeters, and the wall thickness does not exceed half a millimeter. At the same time, it is important that the surface of such pipes does not have sharp bends, and their ovality, if present, does not lead to the outer diameter of the product exceeding the deviations allowed by GOST.
The most common steel grades from which pipes of this category are produced are:
- 08HN28MDT;
- 12X18H10;
- 12X18H10T;
- 12X18H12T;
- 08X19H10T;
- 10X23H18;
- 10X17H13M2T;
- 04X18H10;
- 12X17;
- 08X13;
- 08X22H6T;
- 15X25T;
- 12X13;
- and other steel grades belonging to the high-alloy category.
GOST also stipulates the following parameters of the material for the manufacture of pipe products:
- density - 7.7–7.96 g / cm 3;
- the relative elongation is 17–45%;
- temporary resistance - 38–588 kgf / mm 2.
If we talk about the chemical composition of steels used for the production of pipes of this category, then it may contain a small amount of materials belonging to the rare earth group, and the presence in it of such a harmful impurity as sulfur should not exceed two hundredths of a percent.
Table 5. Content of alloying elements and compliance with stainless steel standards (click to enlarge)
In the standard version, stainless pipes of this category are subjected to heat treatment, but GOST admits that, in agreement with the customer, such treatment can be omitted. In cases where heat treatment of pipes of this category is not performed, the degree of their allowable curvature and mechanical characteristics are also negotiated separately.
GOST also regulates the condition of the outer and inner surfaces of pipes made from. According to these requirements, there should be no defects on such surfaces - captivity, cracks and plains. If these defects are present, then their correction is allowed, which should not lead to a decrease in the allowable dimensions of the pipes, such as wall thickness and outer diameter. In this case, the detected defects can be corrected using the following processing methods:
- grinding, which can be subjected to individual sections, as well as the entire surface of the pipe;
- turning;
- boring;
- mechanical cleaning of problem areas.
Although GOST states that the surface of pipes made of stainless steels should be distinguished by a light metallic sheen, it is allowed to have matte areas characterized by gray color on it. The defects of stainless pipes, which are stipulated by the provisions of the regulatory document, also do not include the coloring of individual sections in tint colors. This assumption is acceptable if the finish was not etched in a vacuum or in a protective environment.
Provisions of GOST 9940-81
You can get acquainted with the GOST requirements for hot-formed stainless steel pipes by downloading the document in pdf format from the link below.
GOST 9940-81 Seamless hot-worked pipes made of corrosion-resistant steel. Specifications
GOST 9940-81 contains requirements for seamless stainless steel pipes, which are made using hot deformation technology. GOST 9940-81 also regulates not only the characteristics of tubular products, but also their assortment, according to which they can be produced in the range of outer diameters of 57–325 mm and with a wall thickness in the range of 3.5–32 mm. Pipes that fall under the requirements of the mentioned standard are made from the same steel grades as the above-described pipe products.
The two above GOSTs are almost identical in most of the requirements for stainless steel tubular products, so it is not advisable to consider GOST 9940 separately.
It is also worth mentioning the acceptance of finished pipes made of stainless steel. In this case, not a single pipe is subjected to verification, but a batch of such products that differ in identical characteristics (grade of steel used, geometric parameters, type of heat treatment applied, etc.). An inspected batch may contain no more than 200 units of the same type. Individual products from the tested batch of stainless pipes are subjected to tests for.
One way to produce stainless steel pipes is the seamless method. The final product is obtained from a pipe billet as a result of chemical and thermal processing, a sequence of mechanical deformations. By content production process seamless pipe is manufactured using cold or hot rolling technology.
Cold- and heat-formed stainless steel seamless pipes
The cold process technology has significant advantages:
- Minimum loss of metal.
- The possibility of obtaining a wide range of pipe sizes from the same type of blanks.
- Allows to produce products with a wall of 0.2 mm.
- Minimize wall thickness deviations.
- Excellent surface quality of finished products.
- Durability.
Requirements for pipes according to GOST 9941-81
The surface of products should not have cracks, captivity, sunsets. The external damages received as a result of deadweight deformation are subject to cleaning (polishing) without going beyond the normative limits. These indicators are reflected in tables 1 and 2.
For product dimensions (diameter x wall thickness, mm):
- 100-102 x 1.5-2.9;
- 108-120 x 1.5-3.2;
- 130-150 x 2-3.2;
- 160-200 x 2.5-3.5;
- 220 x 3-3.5;
- 250 x 3-4 -
limit deviations are specified specifically and are given in table 3.
The standard imposes requirements on the curvature parameter of products produced by the seamless cold-rolled method. This value is indicated per 1 m of pipe and is for the diameter:
- less than 15 mm: 1 mm.
- over 15 mm: 2 mm.
For products with a diameter of up to 15 mm and a wall of up to 0.5 mm, the limiting curvature is not normatively established: it can be any, without kinks.
The surface of the pipes is light. Features of the manufacturing process and grade of metal can give a dull color.
Tubular products produced by the cold-formed method must withstand a number of tests:
- tension at a temperature of 350 degrees C;
- flattening / distribution to calculated parameters;
- hydraulic pressure at a stress of 40% tensile strength type steel;
- for intergranular corrosion;
- ultrasonic control.
Cold Rolled Steel Pipe Technology
Directly deformation of workpieces is preceded by chemical preparation- etching. Steel with an alloying content of chromium is pickled by alkaline melts and acid solutions. The result is the conversion and removal of iron oxides and scale.
Next, the pipes are washed with hot and cold water, dried at a temperature of 170 degrees C, and special coatings are applied to prevent the occurrence of defects during further deformations. When rolling through the mill, the workpieces do not come into direct contact with the milling tools.
Billets pass through rolling mills several times. At intermediate stages, they are subjected to additional chemical influences. A significant role is played by heat treatment up to 700-800 degrees C, as a result of which the hardness of the metal decreases (annealing). After the deformations, thermal hardening is carried out, as a result of which the mechanical properties of the products increase.
Dimensions of seamless pipes according to GOST 9941-81 - table
Hot rolled seamless steel pipes
The hot process provides finished products with the following advantages:
- Ideal anti-corrosion properties.
- Durability and impact resistance.
- Allows to produce products with a wall up to 32 mm.
- Competitive price.
Standards for pipes according to GOST 9940-81
Hot-formed pipes are descaled, do not have external defects on both surfaces. If the products are subject to further welding, then it is normatively limited mass fraction sulfur in the material - 0.02%.
The curvature of finished hot-worked products is established by regulations. This value is indicated relative to the wall thickness per 1 m of pipe and is:
- with a wall less than or equal to 10 mm: 1.5 mm;
- with a wall of 10-20 mm: 2 mm;
- with a wall of more than 20 mm: 4 mm.
The requirements of the standard for passing a hydraulic test, a tensile test, and others are similar to the tests established for products manufactured by a cold-formed method.
Hot Rolled Steel Technology
Unlike the cold rolling method, which involves heat treatment of blanks and products at some stages, the hot rolling method is completely carried out on heated metal. For this purpose, special furnaces with the so-called walking hearth are used, in which an overpressure of up to 29.4 Pa is formed.
- swaging mill;
- piercing mill, in which the workpiece becomes a pipe with walls;
- rolling on a continuous mill;
- induction heating and reduction mill.
After reduction, the finished pipes are cooled and cut into the required lengths.
Dimensions of seamless pipes GOST 9940-81 - table
GOST introduced additional restrictions on the diameter of products for some steel grades:
- 108 mm - 08X20H14S2, 08X22H6T, 08X18H12B.
- 140 mm - 08X17H15M3T.
- 168 mm - 10X23H18.
- 219 mm - 10X17H13M2T, 15X28, 08X17T, 12X17.
The main grades of stainless steel for seamless pipes
GOSTs 9940 and 9941 contain 20 grades of alloys that can be used for the manufacture of stainless steel seamless pipes. Of these, the most used are listed below.
Steel 12x18n10t
Steel has excellent anti-corrosion properties, is resistant to oxidation at temperatures up to 900 degrees C, and has high heat resistance.
Properties of pipes made from steel 12x18n10t by cold / hot rolling:
- resistance, kgf/sq.mm: 56/54;
- elongation, %: 35 / 40;
- density, g / cc: 7.95 / 7.9.
Tubular products made of this steel are used for transportation of oxidizing media, organic solvents and some types of organic acids, in cryogenic technologies at a temperature close to absolute zero.
Steel grade 08x18n10t
The stainless steel of this brand is characterized by even better properties for transporting aggressive environments than the previous type. Finds its application in chemical industry as exhibiting high parameters of resistance to intergranular corrosion.
Mechanical properties of tubular products made from steel 08x18n10t by cold / hot rolling:
- resistance, kgf/sq.mm: 54/52;
- elongation, %: 37/40;
- density, g / cc: 7.9.
Pipes made of this type of steel can be operated at any pressure and temperature up to 600 degrees C.
Steel 10x17N13M2T
The type of steel contains 3% molybdenum, which gives it additional properties that steel 12x18 and 08x18 are deprived of. Pipes made of 10x17H13M2T are resistant to chlorine. In acid environments, depending on the type of acid, its concentration and temperature, the annual corrosion rate does not exceed 0.1 mm. The mechanical properties of products made from 10x17N13M2T by the method of cold and hot rolling are the same and are:
- resistance, kgf/sq.mm: 54;
- elongation, %: 35;
- density, g/cc: 8
Steel grade 06xN28MDT
Stainless steel contains molybdenum (up to 3%), an increased amount of nickel (up to 29%) and chromium (up to 25%). It is used in industrial installations requiring transportation of acids and other aggressive media. In accordance with the standard, this steel grade is used in the production of pipes by cold rolling. The mechanical properties of the products are as follows:
- resistance, kgf/sq.mm: 50;
- elongation, %: 30;
- density, g / cc: 7.96
For cold-rolled pipes from 06xN28MDT, special allowable deviations in diameter and wall are established (table 8).
Steel 10x23H18
Belongs to the group of heat-resistant alloys. It can be used to work with aggressive media with temperatures up to 1000 degrees C. At higher temperatures in the air, it is subject to intense oxidation.
Properties of pipes made from 08x18n10t by cold / hot rolling:
- resistance, kgf/sq.mm: 54/50;
- elongation, %: 35/37;
- density, g/cc: 7.95.
Media transported under high pressure at temperatures up to 1000 degrees C lead to a reduction in the service life of products up to 1-10 thousand hours.
Scope of application of steel seamless pipes
Seamless technology is one of the main ways to manufacture thin-walled and thick-walled stainless steel pipes with a precise inner channel. They apply:
- in high pressure installations;
- in power plants;
- in mechanical engineering and aviation industry;
- in the chemical and food industries;
- in gas and oil pipelines.
The scope of their application is wide and covers highly specialized types of production and industry.
Electrowelded stainless steel pipes
The second method for the production of stainless steel tubular products is a simpler and more economical electrofusion method.
Welded Pipe Manufacturing Methods
The main difference between the welded method and the seamless one is that it provides for the manufacture of a pipe not from a finished billet through numerous deformations, thermal and chemical treatments, but for welding a steel sheet bent into a pipe. Next, water cooling, calibration, cutting, and control measures are carried out. If necessary, carry out dead deformation.
A significant reduction in the cost of the production of stainless products by welding made it possible to use them in everyday life: for pipelines, for decorative and construction purposes.
Yulia Petrichenko, expert
Regulations for Welded Stainless Steel Pipe
Specifications for electric-welded products made of anti-corrosion steel are set out in GOST 11068-81. The specification for square and rectangular profile pipes is contained in GOST 8639-82 and GOST 8645-68, respectively.
Dimensions of electrowelded stainless steel pipes
| Outer diameter, mm | Wall thickness, mm | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0,8 | 1,0 | 1,2 | 1,4 | 1,5 | 1,8 | 2,0 | 2,2 | 2,5 | (2,8) | 3,0 | (3,2) | 3,5 | 4,0 | |
| 8 | X | X | X | - | - | - | - | - | - | - | - | - | - | - |
| 9 | X | X | X | - | - | - | - | - | - | - | - | - | - | - |
| 10 | X | X | X | - | - | - | - | - | - | - | - | - | - | - |
| 11 | - | X | X | X | X | X | - | - | - | - | - | - | - | - |
| 12 | X | X | X | X | X | X | X | - | - | - | - | - | - | - |
| 14 | X | X | X | X | X | X | - | - | - | - | - | - | - | - |
| 15 | - | X | X | X | X | X | - | - | - | - | - | - | - | - |
| 16 | X | X | X | X | X | X | X | X | - | - | - | - | - | - |
| (17) | - | X | X | X | X | X | X | X | - | - | - | - | - | - |
| 18 | - | X | X | X | X | X | X | X | - | - | - | - | - | - |
| (19) | - | X | X | X | X | X | X | X | - | - | - | - | - | - |
| 20 | - | X | X | X | X | X | X | X | - | - | - | - | - | - |
| 22 | - | X | X | X | X | X | X | X | - | - | - | - | - | - |
| 25 | - | X | X | X | X | X | X | X | X | - | - | - | - | - |
| 28 | - | - | X | X | X | X | X | X | X | - | - | - | - | - |
| 30 | - | - | X | X | X | X | X | X | X | - | - | - | - | - |
| 32 | - | - | X | X | X | X | X | X | X | X | X | X | - | - |
| 33 | - | - | X | X | X | X | X | X | X | X | X | X | - | - |
| 34 | - | - | X | X | X | X | X | X | X | X | X | X | - | - |
| 35 | - | - | X | X | X | X | X | X | X | X | X | X | - | - |
| 36 | - | - | X | X | X | X | X | X | X | X | X | X | - | - |
| 38 | - | - | X | X | X | X | X | X | X | X | X | X | - | - |
| 40 | - | - | X | X | X | X | X | X | X | X | X | X | - | - |
| 42 | - | - | X | X | X | X | X | X | X | X | X | X | - | - |
| 43 | - | - | X | X | X | X | X | X | X | X | X | X | - | - |
| 45 | - | - | X | X | X | X | X | X | X | X | X | X | - | - |
| 48 | - | - | - | X | X | X | X | X | X | X | X | X | - | - |
| 50 | - | - | - | X | X | X | X | X | X | X | X | X | - | - |
| 51 | - | - | - | X | X | X | X | X | X | X | X | X | - | - |
| 53 | - | - | - | X | X | X | X | X | X | X | X | X | - | - |
| 55 | - | - | - | X | X | X | X | X | X | X | X | X | - | - |
| 56 | - | - | - | X | X | X | X | X | X | X | X | X | - | - |
| 57 | - | - | - | X | X | X | X | X | X | X | X | X | - | - |
| 60 | - | - | - | X | X | X | X | X | X | X | X | X | - | - |
| 63 | - | - | - | X | X | X | X | X | X | X | X | X | - | - |
| 65 | - | - | - | X | X | X | X | X | X | X | X | X | X | X |
| 70 | - | - | - | X | X | X | X | X | X | X | X | X | X | X |
| 76 | - | - | - | X | X | X | X | X | X | X | X | X | X | X |
| 83 | - | - | - | - | - | X | X | X | X | X | X | X | X | X |
| 89 | - | - | - | - | - | X | X | X | X | X | X | X | X | X |
| 102 | - | - | - | - | - | X | X | X | X | X | X | X | X | X |
The random length of electric-welded pipe products can vary from 1.5 to 9 m. The measured length should lie within 5-9 m.
Seamless stainless steel pipes are reliable products with a wide range of applications. Their cost is higher than that of welded counterparts, which are more suitable for domestic use.
Have you ever dealt with seamless pipes? What grades of steel do you think are most in demand? Share your opinion in the comments.
STATE STANDARD OF THE UNION OF THE SSR
Introduction date 01.01.83
This International Standard applies to seamless hot-worked stainless steel pipes for general use.
(Revised edition, Rev. No. 3).
1. ASSORTMENT
1.1. Pipes are made according to the outer diameter and wall thickness with the dimensions specified in.
1.2. The length of the pipe is made:
measured length - within the unmeasured, but not more than specified in with a maximum deviation in length + 15 mm; by agreement between the manufacturer and the consumer, it is allowed to manufacture measuring pipes with a length exceeding that specified in;
length, a multiple of the measured length, - within the measured length with an allowance for each cut of 5 mm and with a maximum deviation along the entire length of + 15 mm. Minimum multiple length 300 mm;
limited length - within the measured length with a maximum deviation in length ± 500 mm;
random length - from 1.5 to 10 m; by agreement between the manufacturer and the consumer, it is allowed to manufacture pipes with a length of more than 10 m.
|
Outer diameter, mm |
Measuring pipes length, m, no more, with wall thickness, mm |
||||||||||||||||||||||||||||||
|
3,5 |
4 |
4,5 |
5 |
5,5 |
6 |
6,5 |
7 |
7,5 |
8 |
8,5 |
9 |
9,5 |
10 |
11 |
12 |
13 |
14 |
15 |
16 |
17 |
18 |
19 |
20 |
22 |
24 |
25 |
26 |
28 |
30 |
32 |
|
|
57 |
By agreement with the manufacturer |
||||||||||||||||||||||||||||||
|
60 |
|||||||||||||||||||||||||||||||
|
68 |
|||||||||||||||||||||||||||||||
|
73 |
|||||||||||||||||||||||||||||||
|
76 |
|||||||||||||||||||||||||||||||
|
83 |
By agreement between the manufacturer and the consumer |
||||||||||||||||||||||||||||||
|
89 |
|||||||||||||||||||||||||||||||
|
95 |
|||||||||||||||||||||||||||||||
|
102 |
|||||||||||||||||||||||||||||||
|
108 |
|||||||||||||||||||||||||||||||
|
114 |
|||||||||||||||||||||||||||||||
|
121 |
|||||||||||||||||||||||||||||||
|
127 |
|||||||||||||||||||||||||||||||
|
133 |
|||||||||||||||||||||||||||||||
|
140 |
|||||||||||||||||||||||||||||||
|
146 |
|||||||||||||||||||||||||||||||
|
152 |
|||||||||||||||||||||||||||||||
|
159 |
By agreement between the manufacturer and the consumer |
||||||||||||||||||||||||||||||
|
168 |
7 |
6,5 |
6,5 |
6,5 |
6 |
6 |
5,5 |
5,5 |
5 |
4,5 |
4,5 |
4,5 |
3 |
3 |
|||||||||||||||||
|
180 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
8 |
8 |
7,5 |
7,5 |
7 |
7 |
6,5 |
6,5 |
6,5 |
6 |
6 |
5,5 |
5,5 |
5 |
4,5 |
4,5 |
4,5 |
4 |
3,5 |
3,5 |
||
|
194 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
8 |
7,5 |
7 |
7 |
6,5 |
6,5 |
6,5 |
6 |
6 |
5,5 |
5,5 |
5 |
4,5 |
4,5 |
4,5 |
4 |
3,5 |
3,5 |
||
|
219 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
8 |
8 |
7,5 |
7,5 |
7 |
6,5 |
6,5 |
5,5 |
5,5 |
5 |
4,5 |
4,5 |
4,5 |
4 |
3,5 |
3,5 |
||
|
245 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
8 |
8 |
7,5 |
7 |
7 |
6,5 |
6 |
5,5 |
5 |
4,5 |
5 |
4,5 |
4,5 |
- |
- |
- |
- |
|
273 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
8 |
8 |
7,5 |
7 |
6,5 |
6 |
5,5 |
5,5 |
5 |
4,5 |
- |
- |
- |
- |
- |
- |
- |
|
325 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
6,5 |
6 |
5,5 |
5 |
5 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
Notes:
1. Pipes made of steel grades 08X17T, 15X28, 12X17, 10X17H13M2T are made with a diameter of no more than 219 mm; from steel grade 08X17H15M3T - with a diameter of not more than 140 mm, size 159´ 9 mm; from steel grade 10X23H18 - with a diameter of not more than 168 mm; from steel grades 08Kh18N12B, 08Kh22N6T, 08Kh20N14S2 - with a diameter of not more than 108 mm.
2. By agreement between the manufacturer and the consumer, it is allowed to manufacture pipes with dimensions not specified in.
3. The mass of 1 m of pipes, kg, is calculated by the formula
,
whereD n - nominal outer diameter, mm;
s - nominal wall thickness, mm;
- metal density, g / cm 3, depending on the steel grade in accordance with.
4. Pipes with a diameter of 76 to 95 mm with a wall thickness of 3.5 - 4.0 mm, a diameter of 133 to 152 mm with a wall thickness of 4.0-5.5 mm, a diameter of less than 76 mm will be produced after the development of the equipment.
1.3. In a batch of pipes of random length, no more than 15% of pipes with a length of 0.75 to 1.5 m are allowed.
1.4. Limit deviations for the outer diameter and wall thickness are indicated in Table. 2.
|
Pipe dimensions |
Limit deviations for manufacturing accuracy, % |
|
|
ordinary |
high |
|
|
By outside diameter |
± 1,5 |
± 1,0 |
|
By wall thickness, mm: |
||
|
8 or less |
+20,0 |
+12,5 |
|
-15,0 |
-15,0 |
|
|
more than 8 to 20 |
± 15,0 |
+12,5 |
|
-15,0 |
||
|
over 20 |
+12,5 |
|
|
-15,0 |
± 12,5 |
|
1.5. The ovality should not lead the diameter of the pipes beyond the limit deviations.
1.6. The curvature of pipes in any section 1 m long should not exceed:
1.5 mm - in wall thickness up to 10 mm inclusive;
2 mm - with a wall thickness over 10 to 20 mm inclusive;
4 mm - with a wall thickness over 20 mm.
1.7. The ends of the pipes must be cut at a right angle and cleaned of burrs, chamfering is allowed when they are removed. At the request of the consumer, at the ends of pipes with a wall thickness of more than 5 mm, there must be a chamfer for welding.
Legend Examples
Pipe with an outer diameter of 76 mm, a wall thickness of 5 mm, the usual manufacturing accuracy, random length, made of steel grade 08X18H10T:
Trumpet 76´ 5 - 08X18H10T GOST 9940-81
The same, high-precision manufacturing (c), length multiple (cr) 1500 mm:
Trumpet 76v´ 5v´ 1500cr - 08X18H10T GOST 9940-81
The same, the usual manufacturing accuracy, measured length (m) 3000 mm:
Trumpet 76´ 5 ´ 3000m - 08X18H10T GOST 9940-81
The same, the usual manufacturing accuracy, measured length 3000 mm with the remainder:
Trumpet 76´ 5 ´ 3000 - 08X18H10T GOST 9940-81
The same, high-precision manufacturing (c), limited length (og) 3000 mm:
Trumpet 76v´ 5v´ 3000og - 08X18H10T GOST 9940-81
2. TECHNICAL REQUIREMENTS
2.1. Pipes are manufactured in accordance with the requirements of this standard and according to the technical regulations approved in the prescribed manner, from steel grades specified in
15X28
441(45)
17
7,60
15X25T
441(45)
17
7,60
04Х18Н10
441(45)
40
7,90
10X23H18
491(50)
37
7,95
08Х17Н15М3Т
510(52)
35
8,10
08X18H10
510(52)
40
7,90
08X18H10T
510(52)
40
7,90
08X18N12B
510(52)
38
7,90
08Х18Н12Т
510(52)
40
7,95
08Х20Н14С2
510(52)
35
7,70
10X17H13M2T
529(54)
35
8,00
12X18H9
529(54)
40
7,90
12X18H10T
529(54)
40
7,90
12X18H12T
529(54)
40
7,95
17X18H9
568(58)
40
7,90
08Х22Н6Т
588(60)
24
7,60
Notes:
1. For pipes with ratioD n / S равным или менее 8 из стали марок 04Х18Н10, 08Х20Н14С2, 10Х17Н13М2Т, 08Х18Н12Т, 10Х23Н18, 08Х18Н10, 08Х18Н10Т, 08Х17Н15М3Т, 12Х18Н10Т, 12Х18Н12Т, 12Х18Н9, 17Х18Н9, 08Х22Н6Т допускается снижение временного сопротивления разрыву на 19,6 Н/мм 2 (2 кгс/мм 2).
2. At the request of the consumer, for pipes made of steel grades 12X18H10T, 12X18H12T, 08X18H10T, the yield strength is determined.
3. The yield strength for steel grade 12X18H10T must be at least 216.0 N / mm 2 (22 kgf / mm 2).
4. The yield strength standards for steel grades 12X18H12T and 08X18H10T are set by agreement between the manufacturer and the consumer.
(Changed edition, Rev. No. 1, 2, 3, 4).
2.3. At the request of the consumer, the pipes must withstand a tensile test at a temperature of 623 K (350 ° FROM).
The norms of temporary tensile strength and yield strength are set by agreement between the manufacturer and the consumer.
(Changed edition, Rev. No. 1, 3).
2.4. Captivity, flaws, sunsets, cracks are not allowed on the outer and inner surfaces of the pipes. It is allowed to remove defects by local cleaning, continuous or local grinding, boring and turning, provided that the value of boring, turning or continuous grinding does not take the diameter and wall thickness beyond the minus deviations, and local cleaning or grinding - the wall thickness beyond the minus deviations indicated in .
Without stripping, single films, ripples, risks, traces of indentation of scale are allowed, provided that they do not take the wall thickness beyond minus limit deviations.
At the request of the consumer, individual captives must be cleaned.
(Revised edition, Rev. No. 2).
2.5. At the request of the consumer, the pipes are made cleaned of scale.
2.6. At the request of the consumer, the pipes must withstand hydraulic pressure R 1 in accordance with the requirements of GOST 3845 at an allowable stress equal to 40% of the tensile strength for a given steel grade.
The ability of pipes to withstand hydraulic pressure is ensured by the production technology.
2.7. По требованию потребителя трубы из стали марок 04Х18Н10, 08Х20Н14С2, 10Х17Н13М2Т, 08Х18Н12Б, 10Х23Н18, 08Х18Н10, 08Х18Н10Т, 08Х18Н12Т, 08Х17Н15М3Т, 12Х18Н10Т, 12Х18Н12Т, 12Х18Н10, 17Х18Н9, 08Х22Н6Т должны выдерживать сплющивание до получения между поверхностями расстояния ( H), mm, calculated by the formula
where s- nominal wall thickness, mm;
D- nominal outer diameter, mm,
or expanding to increase the outer diameter by 10% with a mandrel with a taper angle of 30 ° ; it is allowed to use mandrels with a taper angle of 6 and 12 ° .
2.8. At the request of the consumer, which is indicated in the order, pipes made of steel grades 10X17H13M2T, 08X17H15M3T, 08X22H6T, 04X18H10, 08X18H10, 08X18H10T, 12X18H10T, 12X18H9, 08X18H12T, 12X18H12N
2.9. At the request of the consumer, they must undergo ultrasonic testing. The size of an artificial defect is set by agreement between the manufacturer and the consumer.
3. ACCEPTANCE RULES
3.1. Pipes are accepted in batches. The batch must consist of pipes of the same size in terms of diameter and wall thickness, one steel grade and one type of heat treatment, and at the request of the consumer - one heat and be issued with one quality document for the pipe billet.
The number of pipes in a batch should be no more than 200 pcs.
3.2. Each pipe is subjected to surface control, dimensions, hydraulic pressure, ultrasonic control.
3.3. For quality control, the following items are selected from the batch:
two pipes - for tension;
one pipe - for flattening or distribution;
two pipes - for intergranular corrosion.
If unsatisfactory test results are obtained for at least one of the indicators, repeated tests are carried out on it on a double number of pipes selected from the same batch.
The retest results apply to the entire lot.
(Changed edition, Rev. No. 4)
3.4. Deleted (Change No. 4)
4. TEST METHODS
4.1. For quality control, one sample is cut from each selected pipe for each type of test.
4.2. Inspection of the surface of the pipes is carried out visually.
4.3. The length of the pipes is checked with a tape measure according to GOST 7502.
(Changed edition, Rev. No. 4)
4.4. The curvature of the pipes is checked with a straightedge according to GOST 8026 and a probe according to the regulatory documentation.
(Changed edition, Rev. No. 3, 4).
4.5. The outer diameter and ovality are controlled with a smooth micrometer of the MK type according to GOST 6507, with sheet staples according to GOST 18360, GOST 18365.
The wall thickness is controlled by a pipe micrometer of the MT type according to GOST 6507.
(Changed edition, Rev. No. 4)
4.6. The tensile test is carried out according to GOST 10006, GOST 19040 (at a temperature of 623 K).
The speed of movement of the movable grip is no more than 10 mm per 1 min. It is allowed to exceed the test speed up to 40 mm in 1 min after reaching the yield strength.
It is allowed to control the mechanical properties by the hardness method according to the normative and technical documentation.
In case of disagreement in evaluating the results, the tests are carried out according to GOST 10006.
(Revised edition, Rev. No. 1).
4.7. The expansion test is carried out on pipes with a diameter of up to 146 mm inclusive with a wall thickness of not more than 10 mm in accordance with GOST 8694.
(Revised edition, Rev. No. 1).
4.8. The flattening test is carried out on pipes with a wall thickness of not more than 10 mm in accordance with GOST 8695.
If small defects are found on the flattened samples, which are the result of external defects that are allowed without cleaning, the sample is re-tested from the same pipe with preliminary cleaning of the surface to a depth of maximum deviations in wall thickness, but not more than 0.2 mm from the side on which the defects.
4.9. The hydraulic pressure test is carried out in accordance with GOST 3845 with holding pipes under pressure for at least 10 s.
4.9.1. Instead of testing with hydraulic pressure, it is allowed to inspect each pipe by non-destructive methods in accordance with GOST 17410 and regulatory and technical documentation from 01.01.90.
(Introduced additionally, Rev. No. 1).
4.10. Ultrasonic testing is carried out in accordance with GOST 17410 and normative and technical documentation.
4.11. The resistance to intergranular corrosion is tested by the AM or AMU methods according to GOST 6032. In case of disagreement in evaluating the results, the test is carried out by the AM method.
By agreement between the manufacturer and the consumer, it is allowed to test the resistance to intergranular corrosion of steel grades 12X18H10T and 08X18H10T by the method of PT GOST 9.914. In case of disagreement in the evaluation of the results, the verification is carried out by the AM method according to GOST 6032.
(Changed edition, Rev. No. 4)
5. MARKING, PACKAGING, TRANSPORT AND STORAGE
5.1. Marking, packaging, transportation and storage - according to GOST 10692.
INFORMATION DATA
1. DEVELOPED AND INTRODUCED USSR Ministry of Ferrous Metallurgy
DEVELOPERS
V.P. Sokurenko(topic leader) L.G. Kovaleva, V.N. Rovensky, G.A. Gorovenko
2. APPROVED AND INTRODUCED Decree of the USSR State Committee for Standards dated 20.07.81 No. 3445
3. Periodicity of inspection - 5 years
4. REPLACE GOST 9940-72
5. REFERENCE REGULATIONS AND TECHNICAL DOCUMENTS
6. The validity period was removed under the Protocol of the Interstate Council for Standardization, Metrology and Certification (IUS 2-93)
7. REPUBLICATION with Changes No. 1, 2, 3,4, approved in June 1987, June 1988, August 1988, April 2001. (IUS 11-87, 9-88, 12-88, 7-2001 )
Among the range of pipes offered by Energocontrol, there are products designed to solve a wide range of tasks. For example, these are seamless pipes that are resistant to corrosion and are designed for operation in conditions far from ideal. Now, in order to find a supplier of a range of stainless steel pipes manufactured in accordance with GOST 9940-81, you do not have to "surf" the Internet, since you can always find up-to-date information and find interesting offers on the company's website.
Why is cooperation with Energocontrol LLC the most preferable? Our company offers low prices and a wide range of products produced according to interstate standards. Stainless seamless pipes can be purchased both wholesale and retail buyers. The presence of our own warehouses located in St. Petersburg and Moscow, as well as the possibility of delivery to any region of Russia - these are truly favorable conditions that are available only to a few suppliers.
Status GOST 9940-81
This standard applies to corrosion-resistant, seamless, hot-formed pipes. The wall thickness of the products varies between 3.5-32 mm, and the diameter is 57-325 mm. As for the length, it should not deviate up or down by more than 15 mm, although manufacturers often manufacture products according to the parameters specified by the customer, but within the standard, with a multiplicity of 300 mm.
The hot-formed pipe can be manufactured not only in accordance with GOST, but also in accordance with technical regulations. GOST 9940-81 is valid, and any steel grade that falls under its standard can be used in the manufacture of products.
Application area
Cold-formed pipe is endowed with greater strength, but hot-formed is characterized by plasticity and flexibility, and if the pipe is made of steel 20x23n18, then this means one thing: the product is characterized by increased heat resistance, therefore, it can be used to create structures that will constantly be exposed to ultra-high temperatures. Hot-rolled pipes in accordance with GOST 9940-81, made from less heat-resistant steel grades, but not devoid of increased corrosion resistance, can be used:
- In mechanical engineering, shipbuilding and aircraft building. Elements of engines, cooling systems and other units are often made from hot-rolled pipe, inside which there is a high risk of corrosion, temperature and pressure drops.
- in the nuclear industry. Corrosion-resistant steel is especially in demand in this area, as well as pipe products made from such a material, which combines a whole list of positive properties. These include increased resistance to aggressive environments, high strength characteristics and the absence of weld, which is very important, since it completely eliminates the possibility of leakage of working solutions and other substances, often dangerous.
- Chemical industry. Any substances can be distilled through seamless hot-rolled pipes without fear of leaks and other force majeure.
- Energy and building sector. If the heating system is created with the involvement of just such a pipe, then there can be no doubt about its reliability. Products made from heat-resistant steel grades are ideal for the manufacture of high-pressure boilers, steam generators and other installations.
- Other sectors of the economy. These include: oil and gas production and processing of minerals, as well as food, light and processing industries.
