|
| Markenbezeichnung: | Yuhong |
| Modellnummer: | ASTM A335 P11 |
| MOQ: | Abhängig von den Anforderungen der Kunden |
| Preis: | Verhandelbar |
| Zahlungsbedingungen: | TT, LC |
| Versorgungsfähigkeit: | Gemäß den Anforderungen der Kunden |
ASTM A335 P11 Alloy Steel Seamless Pipe For High-Temperature Boiler Service
The ASTM A335 P11 seamless pipe is a high-performance, seamless alloy steel tube designed to safely contain steam, process gases, and other fluids under extreme heat and pressure for the decades-long lifespan of a power plant or refinery. Its specific blend of chromium and molybdenum makes it an essential material for the energy and heavy industrial sectors. Its primary application is in power plants, refineries, and industrial process plants for carrying fluids and gases at elevated temperatures and pressures where standard carbon steel pipes would fail.
Basic Introductions of ASTM A335 P11 seamless pipe’s properties:
1. Chemical Composition
The chemical composition is the fundamental definition of the grade. The values are percentages by weight, with the remainder being Iron (Fe). The standard specifies maximum values unless a range is given.
| Element | Composition (%) | Notes |
| Carbon (C) | 0.05 - 0.15 | Provides strength. Controlled within a tight range for weldability and toughness. |
| Manganese (Mn) | 0.30 - 0.60 | Aids in strength and hardenability. Helps deoxidize the steel during manufacturing. |
| Phosphorus (P) | 0.025 max | An impurity. Kept very low as it reduces toughness and increases brittleness. |
| Sulfur (S) | 0.025 max | An impurity. Kept very low as it causes brittleness (hot shortness) and hampers weldability. |
| Silicon (Si) | 0.50 - 1.00 | Acts as a deoxidizer during steelmaking and enhances strength and oxidation resistance. |
| Chromium (Cr) | 1.00 - 1.50 | Key alloy. Provides resistance to oxidation (scaling) and corrosion, especially from sulfur compounds. |
| Molybdenum (Mo) | 0.44 - 0.65 | Key alloy. Provides high-temperature strength and greatly improves resistance to creep deformation. |
Note: The standard also includes rules for product analysis, which allows for slight variations from the heat (ladle) analysis shown above to account for inevitable segregation during solidification.
2. Mechanical Properties
These properties are the minimum required values for the pipe in the normalized and tempered heat-treated condition. Actual test results from the manufacturer must meet or exceed these values.
| Property | Requirement | Notes & Testing Standard |
| Tensile Strength | 415 MPa min (60,000 psi min) | The maximum stress the material can withstand while being stretched before failing. (ASTM A370) |
| Yield Strength | 205 MPa min (30,000 psi min) | The stress at which the material begins to deform plastically (permanently). A key design parameter for pressure containment. (ASTM A370) |
| Elongation | ≥ 30% (typical for standard specimen) | A measure of ductility. The minimum required elongation decreases slightly as the wall thickness of the pipe increases. |
3. Heat Treatment:
All A335 P11 pipe is supplied in the normalized and tempered condition. This heat treatment process is essential to:
Primary Applications of ASTM A335 P11 seamless pipes:
The unique properties of A335 P11 make it the material of choice in several critical areas:
1. Power Generation Industry (Fossil Fuel & Thermal Plants)
This is one of the largest application areas.
2. Oil & Gas Refineries and Petrochemical Plants
Refineries process hydrocarbons at extreme temperatures, requiring robust piping.
3. Chemical Processing Plants
Similar to refineries, chemical plants use P11 pipes to handle aggressive chemicals and catalysts at high temperatures in various reaction processes.
4. Pressure Vessel Manufacturing
P11 pipes are often used to manufacture headers, manifolds, and other components for pressure vessels that operate at high temperatures.
Why is it Used in These Applications? (The Technical Rationale)
The environments in the applications above present a major challenge: Creep.
Carbon steel (like ASTM A106) loses strength rapidly above 425°C (800°F). Under constant stress at high temperatures, it will deform and eventually rupture—a phenomenon known as creep failure.
ASTM A335 P11, with its chromium and molybdenum content, maintains its mechanical strength at these high temperatures. The alloying elements form stable carbides within the steel's microstructure, which pin the grain boundaries and resist deformation over time.
In simple terms: P11 pipe doesn't "stretch" or "sag" under its own weight and internal pressure over decades of service at high temperatures, whereas carbon steel would.
Video
Video
