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Zhejiang High-temperature SMLS Pipe
QS Steel Pipe: Zhejiang High-temperature SMLS Pipe
Name: Zhejiang High-temperature SMLS Pipe
Material: 5L X42
Standard: API
Size: 6 Inch
Type: Seamless
Schedule: SCH 40
End: Bevel End
Surface of Pipe: Normal Black
Application: Used for High-temperature Service
Material: 5L X42
Standard: API
Size: 6 Inch
Type: Seamless
Schedule: SCH 40
End: Bevel End
Surface of Pipe: Normal Black
Application: Used for High-temperature Service
Quantity
High-temperature SMLS Pipe (6-inch, SCH 40) is specifically engineered for high-temperature applications. Manufactured from API 5L X42 carbon steel with a 6-inch nominal diameter and SCH 40 standard wall thickness, it ensures superior pressure and heat resistance. Featuring beveled ends and a standard black paint finish, it is ideal for high-temperature transportation systems in oil, gas, and chemical industries. Its seamless (SMLS) construction enhances safety and reliability, complying with API standards, making it the optimal choice for high-pressure, high-temperature environments.
High-Temperature Performance of API 5L X42 High-temperature SMLS Pipe
The performance of High-temperature SMLS Pipe under elevated temperatures directly impacts its reliability in industries such as oil & gas, petrochemicals, and power generation. Its standard operational range is -20°C to 450°C, but through special heat treatment and alloy optimization, its high-temperature stability can be significantly enhanced for more demanding conditions.
The performance of High-temperature SMLS Pipe under elevated temperatures directly impacts its reliability in industries such as oil & gas, petrochemicals, and power generation. Its standard operational range is -20°C to 450°C, but through special heat treatment and alloy optimization, its high-temperature stability can be significantly enhanced for more demanding conditions.
1. Standard High-Temperature Performance Analysis
High-temperature SMLS Pipe utilizes API 5L X42 carbon-manganese steel, with its high-temperature properties primarily determined by chemical composition (C, Mn, Si, etc.) and heat treatment condition:
- Short-term high-temperature limit (≤450°C) – Within this range, High-temperature SMLS Pipe maintains stable mechanical properties, with no significant degradation in yield strength (YS) or tensile strength (TS).
High-temperature SMLS Pipe utilizes API 5L X42 carbon-manganese steel, with its high-temperature properties primarily determined by chemical composition (C, Mn, Si, etc.) and heat treatment condition:
- Short-term high-temperature limit (≤450°C) – Within this range, High-temperature SMLS Pipe maintains stable mechanical properties, with no significant degradation in yield strength (YS) or tensile strength (TS).
- Long-term high-temperature service (300°C–450°C) – Risks include carbide precipitation and pearlite spheroidization, which may affect toughness and creep resistance.
Typical High-Temperature Mechanical Data (ASTM A106/A53 Reference):
| Temperature (°C) | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation (%) |
| 20 | ≥289 | ≥415 | ≥20 |
| 300 | ~250 | ~380 | ≥18 |
| 450 | ~220 | ~350 | ≥15 |
2. High-Temperature Stability Enhancement Techniques
(1) Normalizing Treatment
- Process Parameters: Heating to 900°C–950°C, followed by air cooling.
- Effect: Refines grain structure, homogenizes microstructure (ferrite + pearlite), and improves High-temperature SMLS Pipe's softening resistance.
- Result: Increases strength retention at 450°C by 10–15%.
(1) Normalizing Treatment
- Process Parameters: Heating to 900°C–950°C, followed by air cooling.
- Effect: Refines grain structure, homogenizes microstructure (ferrite + pearlite), and improves High-temperature SMLS Pipe's softening resistance.
- Result: Increases strength retention at 450°C by 10–15%.
(2) Quenching & Tempering (Q&T)
- Process Parameters:
- Quenching: Heating to 880°C–920°C, followed by water or oil cooling.
- Tempering: Holding at 600°C–650°C, then slow cooling.
- Effect: Forms tempered sorbite, significantly enhancing high-temperature strength and creep resistance.
- Result: Q&T-treated X42 pipe can withstand **short-term service at 500°C, maintaining tensile strength ≥320 MPa.
- Process Parameters:
- Quenching: Heating to 880°C–920°C, followed by water or oil cooling.
- Tempering: Holding at 600°C–650°C, then slow cooling.
- Effect: Forms tempered sorbite, significantly enhancing high-temperature strength and creep resistance.
- Result: Q&T-treated X42 pipe can withstand **short-term service at 500°C, maintaining tensile strength ≥320 MPa.
(3) Microalloying Optimization
- Added Elements: Nb (niobium), V (vanadium), Ti (titanium).
- Effect: Forms carbonitrides, pinning grain boundaries to suppress grain growth and strength degradation at high temperatures.
- Typical Composition: C≤0.26%, Mn≤1.30%, Nb≤0.05%, V≤0.10%.
- Added Elements: Nb (niobium), V (vanadium), Ti (titanium).
- Effect: Forms carbonitrides, pinning grain boundaries to suppress grain growth and strength degradation at high temperatures.
- Typical Composition: C≤0.26%, Mn≤1.30%, Nb≤0.05%, V≤0.10%.
3. Failure Prevention in High-Temperature Environments
- Creep Control:
- For long-term use (350°C–450°C), calculate Larson-Miller Parameter (LMP) to assess creep life.
- Recommended max allowable stress: ≤60% yield strength (per ASME B31.3).
- Creep Control:
- For long-term use (350°C–450°C), calculate Larson-Miller Parameter (LMP) to assess creep life.
- Recommended max allowable stress: ≤60% yield strength (per ASME B31.3).
- Oxidation Protection:
- In sulfur-rich or high-temperature steam environments, use Cr-Mo coatings or stainless steel-lined composite pipes.
- In sulfur-rich or high-temperature steam environments, use Cr-Mo coatings or stainless steel-lined composite pipes.
4. Application Case Studies
- Petroleum Cracking Units: Normalized High-temperature SMLS Pipe used in 400°C hot oil pipelines with over 10 years of service life.
- Power Plant Boiler Piping: Q&T-treated X42 pipes exhibit zero deformation under 450°C/6MPa steam conditions.
- Petroleum Cracking Units: Normalized High-temperature SMLS Pipe used in 400°C hot oil pipelines with over 10 years of service life.
- Power Plant Boiler Piping: Q&T-treated X42 pipes exhibit zero deformation under 450°C/6MPa steam conditions.
5. User Operation Guidelines
- Material Selection: For >400°C service, prioritize normalized or Q&T-treated High-temperature SMLS Pipe.
- Welding: Preheat to 150°C–200°C to avoid hydrogen-induced cracking.
- Inspection: Conduct ultrasonic testing (UT) and hardness checks to monitor high-temperature degradation.
- Material Selection: For >400°C service, prioritize normalized or Q&T-treated High-temperature SMLS Pipe.
- Welding: Preheat to 150°C–200°C to avoid hydrogen-induced cracking.
- Inspection: Conduct ultrasonic testing (UT) and hardness checks to monitor high-temperature degradation.
Conclusion
Through heat treatment optimization and composition design, High-temperature SMLS Pipe can safely operate below 450°C, with short-term capability up to 500°C under special conditions. Users should select appropriate treatments based on service conditions and implement protective measures to extend pipeline lifespan.
Through heat treatment optimization and composition design, High-temperature SMLS Pipe can safely operate below 450°C, with short-term capability up to 500°C under special conditions. Users should select appropriate treatments based on service conditions and implement protective measures to extend pipeline lifespan.
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