ASTM A335M: Standard Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service
ASTM A335M: Standard Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service
This standard is specifically relevant to pipes made from ferritic alloys that are used in power plants, refineries, and other industrial settings where high-temperature performance is essential. The pipes are designed to withstand the elevated temperatures and pressures typically found in these applications.
Below is a detailed breakdown of the technical aspects of ASTM A335M with a focus on the chemical composition, mechanical properties, testing, dimensions, and typical applications.
1. Scope of ASTM A335M
ASTM A335M covers seamless ferritic alloy-steel pipes designed for use in high-temperature service, specifically in applications where exposure to elevated temperatures (often exceeding 500°C or 932°F) is required. These pipes are generally used in:
- Power plants (for steam and hot water lines)
- Chemical and petrochemical industries
- Refining industries (for pipes in high-pressure systems)
- Boilers and superheaters in power generation systems.
The standard also includes the mechanical properties, heat treatment requirements, and chemical composition specifications for these materials to ensure safe and reliable performance under the harsh conditions in which they are used.
2. Chemical Composition
The chemical composition of the alloy steel used for ASTM A335M pipes plays a critical role in defining the material’s strength, resistance to oxidation, creep, and other high-temperature properties.
Table 1: Typical Chemical Composition for ASTM A335M Pipe Grades
| Grade | C (Carbon) | Mn (Manganese) | Si (Silicon) | P (Phosphorus) | S (Sulfur) | Cr (Chromium) | Mo (Molybdenum) | V (Vanadium) | Ni (Nickel) | Cu (Copper) |
|---|---|---|---|---|---|---|---|---|---|---|
| A335 P5 | 0.05–0.15% | 0.30–0.60% | 0.50% max | 0.025% max | 0.010% max | 4.00–6.00% | 0.45–0.65% | – | – | – |
| A335 P9 | 0.06–0.15% | 0.30–0.60% | 0.50% max | 0.025% max | 0.010% max | 8.00–10.00% | 0.90–1.10% | – | – | – |
| A335 P11 | 0.05–0.15% | 0.30–0.60% | 0.50% max | 0.025% max | 0.010% max | 1.00–1.50% | 0.44–0.65% | – | – | – |
| A335 P22 | 0.05–0.15% | 0.30–0.60% | 0.50% max | 0.025% max | 0.010% max | 2.25–2.75% | 1.00–1.25% | – | – | – |
| A335 P91 | 0.08–0.12% | 0.30–0.60% | 0.50% max | 0.025% max | 0.010% max | 8.00–9.50% | 0.85–1.05% | 0.18–0.25% | 0.20–0.60% | – |
- Notes:
- P5, P9, P11, P22, P91 represent various grades of ferritic steel that are used based on the temperature range and specific mechanical requirements.
- The Chromium (Cr) content plays a significant role in the pipe’s resistance to oxidation, especially at high temperatures.
- Molybdenum (Mo) helps improve creep resistance, which is essential for high-temperature applications.
- Vanadium (V) in P91 helps improve the steel’s strength and resistance to thermal fatigue.
3. Mechanical Properties
The mechanical properties of ASTM A335M pipes are critical for their application in high-temperature environments. These properties include tensile strength, yield strength, elongation, hardness, and impact toughness.
Table 2: Mechanical Properties of ASTM A335M Pipe Grades
| Grade | Tensile Strength (ksi) | Yield Strength (ksi) | Elongation (%) | Hardness (Brinell) |
|---|---|---|---|---|
| A335 P5 | 60–85 | 30–60 | 20–30 | 140-200 |
| A335 P9 | 75–90 | 50–75 | 20–30 | 160-220 |
| A335 P11 | 70–85 | 50–70 | 20–30 | 160-220 |
| A335 P22 | 65–85 | 45–60 | 20–30 | 160-220 |
| A335 P91 | 85–100 | 70–90 | 20–30 | 200-250 |
- Tensile Strength indicates the material’s ability to resist breaking under tension.
- Yield Strength measures the material’s ability to resist deformation under stress.
- Elongation reflects the material’s ductility or ability to stretch without breaking.
- Hardness gives an indication of the material’s resistance to surface deformation, wear, and scratches.
4. Heat Treatment and Manufacturing Process
The pipes covered by ASTM A335M must undergo specific heat treatments to ensure their high-temperature serviceability:
Heat Treatment Process:
- Normalization: This process involves heating the pipe to a temperature slightly above the critical range and then allowing it to cool in air. This process refines the grain structure, improving both strength and toughness.
- Tempering: After hardening, pipes may be tempered at a lower temperature to reduce brittleness while maintaining strength.
- Annealing: Some grades may require annealing to achieve better ductility and reduce hardness.
- Quenching: The material may be quenched (rapid cooling) to harden it, especially in high-stress applications.
Manufacturing Process:
The pipe is cold-formed and hot-rolled to the required diameter and thickness. A precise seamless forming process is employed to ensure uniformity in wall thickness and diameter, which is critical for pressure and temperature resistance. After forming, the pipe is heat-treated, and often subjected to rigorous inspection to ensure compliance with specifications.
5. Testing and Inspection
ASTM A335M pipes must undergo several tests to ensure they meet the stringent requirements of high-temperature service.
Types of Testing:
- Tensile Test: To measure the pipe’s strength and elongation under stress.
- Impact Test: Typically conducted at sub-zero temperatures to determine the material’s toughness and resistance to cracking.
- Hardness Test: To evaluate the resistance of the pipe material to surface deformation.
- Hydrostatic Test: To check the integrity of the pipe under internal pressure.
- Ultrasonic Test: For detecting internal flaws, ensuring no defects that could affect the pipe’s serviceability at high temperatures.
6. Dimensional Tolerances
The dimensions of ASTM A335M pipes must comply with strict tolerances to ensure their proper fit in high-pressure and high-temperature applications.
Table 3: Dimensional Tolerances for ASTM A335M Pipes
| Outside Diameter (OD) | Wall Thickness | Length |
|---|---|---|
| 2 inches to 24 inches | 0.250 inches to 1.000 inches | 12 ft to 24 ft |
| Over 24 inches | 0.250 inches to 1.000 inches | Custom lengths available |
- Wall Thickness is critical for pressure applications. The pipes must be capable of withstanding high internal pressures, so thickness is chosen based on the specific service requirements.
- Length: Pipes are typically produced in fixed lengths (usually 12 to 24 feet), but longer lengths can be customized depending on the customer’s needs.
7. Applications and Use Cases
ASTM A335M pipes are used in environments where high strength, resistance to oxidation, and the ability to withstand high temperatures are essential. Some key applications include:
- Power Generation: In boilers, superheaters, and steam lines, where pipes are exposed to high-pressure steam.
- Petrochemical Industry: Used in refineries for pipelines carrying corrosive and high-temperature fluids.
- Industrial Heat Exchangers: Pipes used to transfer heat between fluids while withstanding both temperature and pressure.
- Fossil Fuel Industry: In pipelines carrying high-temperature gases and fluids in power plants.
ABTER STEEL is a leading China supplier of ASTM A213/ASME SA213 alloy steel tubes, steel grades includes T2, T11, T12, T22, T91, T92,etc, we can offer you ASTM A213 steel tube of all grade and dimension range.ASTM A213 specification covers seamless ferritic and austenitic steel boiler, super heater, and heat-exchanger tubes.
ASTM A335(or ASME SA335) is the standard specification for seamless ferritic alloy steel pipe for high temperature service. It covers steel grades from P1 to P5, P9, P11, P12, P91. Grades P11/P22 and P91/92 pipes are commonly used in power generation and petrochemical industries.
ASTM A335 /ASME SA335,covers chrome moly seamless pipes intended for high temperature service.It is commonly used in the power generation and petrochemical industries including refineries,power plants,petro-chemical plants,hydrocrackers,cokers,high and super high temperature lines, reheat lines, distillation, oil field services, etc.
ASTM A519 steel mechanical tubing is used in various industries due to its excellent mechanical properties and uniformity. These tubes are widely employed in applications that demand high strength, toughness, and resistance to wear.
Nickel alloy steel pipe is a type of alloy steel pipe that contains a significant amount of nickel as one of its primary alloying elements. The addition of nickel to the alloy steel pipe enhances its mechanical properties, such as strength, toughness, and corrosion resistance.
DIN/EN 10305-1 and DIN/EN 10305-4 standards provide specifications for cold-drawn seamless steel tubes used in various applications, including gas cylinders.
