|
Still deciding? Get samples of $ !
Request Sample
|
| Customization: | Available |
|---|---|
| Type: | Stainless Steel Pipes |
| Standard: | ASTM, AISI, GB, JIS, DIN, EN |
Suppliers with verified business licenses
Audited Supplier Audited by an independent third-party inspection agency
| Feature | Description |
|---|---|
| Standard | GOST 9941 (CIS/Russian Standard) |
| Process | Seamless (Hot- and/or Cold-Deformed) |
| Primary Material | Stainless Steel (Austenitic & Austenitic-Ferritic grades) |
| Key Applications | 1. Mechanical Engineering 2. Chemical Industries 3. High-Temperature Service |
| Key Properties | High Strength, Excellent Corrosion Resistance, Good High-Temperature Performance |
| Key Tests | Hydrostatic Test, Mechanical Tests, Intergranular Corrosion Test, NDT |
1. Governing Standard and Origin:
This product is manufactured according to the GOST 9941 standard.
GOST (Gosudarstvennyy Standart) is a set of technical standards maintained by the CIS (Commonwealth of Independent States), with its historical origin in the Soviet Union. It is widely used in Russia, Ukraine, Kazakhstan, and other former Soviet states.
This standard is the primary specification for stainless steel seamless pipes within this regulatory framework.
2. Manufacturing Process:
The pipes are explicitly seamless (hot-deformed and/or cold-deformed), meaning they are produced without a longitudinal weld seam.
The manufacturing process typically involves piercing a solid, heated stainless steel billet to create a hollow shell (hot deformation). This shell is then further processed through hot rolling, extrusion, or cold drawing (cold deformation) to achieve the final dimensions, mechanical properties, and surface finish.
The seamless construction ensures a homogeneous structure in all directions, providing superior mechanical strength and reliability under high pressure, mechanical stress, and thermal cycling.
3. Primary Material Grades:
GOST 9941 covers a range of austenitic and austenitic-ferritic stainless steel grades, comparable to international standards.
Common grades include:
08Kh18N10 (08Х18Н10): Similar to AISI 304, a general-purpose austenitic stainless steel.
08Kh18N10T (08Х18Н10Т): A stabilized grade with Titanium (similar to AISI 321), offering improved resistance to intergranular corrosion, especially after welding or high-temperature exposure.
12Kh18N10T (12Х18Н10Т): A higher carbon variant of the above.
08Kh17N13M2T (08Х17Н13М2Т): A molybdenum-bearing stabilized grade similar to AISI 316Ti.
08Kh22N6T (08Х22Н6Т): An example of an austenitic-ferritic (duplex) stainless steel.
4. Key Intended Applications and Service Conditions:
The standard designates these pipes for use in three critical and demanding sectors:
Mechanical Engineering: Used for manufacturing high-strength, corrosion-resistant components, hydraulic systems, cylinders, precision mechanical parts, and structural elements where reliability is paramount.
Chemical Industries: Ideal for constructing equipment, pipelines, and systems that handle aggressive media such as acids, alkalis, and solvents. Their excellent corrosion resistance is a primary requirement in these environments.
High-Temperature Service: Specifically designed to maintain structural integrity and oxidation resistance at elevated temperatures. This makes them suitable for applications like:
Heat exchangers
Superheaters and boiler tubes in power generation
Furnace components
Petrochemical cracking tubes
5. Key Technical Requirements and Testing:
The GOST 9941 standard mandates strict controls to ensure performance:
Chemical Composition: Precise limits for all alloying and impurity elements are specified for each grade.
Mechanical Properties: Minimum requirements for Tensile Strength (Rm), Yield Strength (Rp0.2), and Elongation (A) are defined to guarantee structural performance.
Hydrostatic Pressure Test: Every pipe is subjected to a non-destructive test where it is pressurized to a specified level to verify its ability to hold pressure without leaking or deformation.
Non-Destructive Testing (NDT): Ultrasonic or other NDT methods are often employed to check for internal and surface imperfections.
Intergranular Corrosion Test: A critical test for stainless steels, especially for applications in chemical industries. Samples are exposed to a corrosive environment to ensure resistance to sensitization and intergranular attack.
Dimensional and Geometrical Tolerances: Strict limits are set for outer diameter, wall thickness, ovality, and straightness.
6. Comparison with Other Standards:
While serving a similar purpose to standards like ASTM A213 (seamless ferritic and austenitic alloy-steel boiler tubes) or EN 10216-5 (seamless stainless steel tubes for pressure purposes), GOST 9941 operates within its own distinct regulatory and certification system, often requiring specific documentation (GOST Certificates of Conformity).
){kind=link}