GB/T 9711-2011 L175 PSL1 SSAW Pipeline Steel
GB/T 9711-2011 L175 PSL1 SSAW Pipeline Steel - Comprehensive Material Data & Equivalents
Full technical analysis of L175 PSL1 spiral submerged-arc welded pipe according to GB/T 9711-2011, including chemical composition, mechanical properties, physical data, and international equivalents.
Hot strip rolling, spiral forming, double-sided submerged arc welding, sizing, testing
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GB/T 9711-2011 L175 PSL1 SSAW Pipeline Steel Introduction
GB/T 9711-2011 L175 is a basic carbon-manganese steel grade for longitudinally or spirally welded steel pipes used in pipeline transportation systems in the petroleum and natural gas industries. As a PSL1 (Product Specification Level 1) material, it is intended for less demanding service conditions where notch toughness is not a mandatory requirement. L175 designates a minimum yield strength of 175 MPa. The material is supplied primarily in the form of spiral submerged arc welded (SSAW) pipe, offering cost-effective production for large-diameter, medium-wall-thickness pipes. The grade features good weldability, formability, and adequate strength for low-pressure gathering lines, water pipelines, and structural applications. Delivery condition is typically as-welded or normalized, depending on the manufacturing process and final wall thickness.
GB/T 9711-2011 L175 PSL1 SSAW Pipeline Steel Chemical Composition
Chemical requirements for the L175 PSL1 steel grade in accordance with GB/T 9711-2011, Table 7. The analysis applies to heat (cast) analysis; product analysis tolerances are defined in the standard. Elements not listed may be present, but their contents shall not exceed the limits agreed upon for the product specification level.
| Element | Standard Value (max, %) | Remarks |
|---|---|---|
| C (Carbon) | 0.21 | - |
| Mn (Manganese) | 1.00 | - |
| P (Phosphorus) | 0.030 | - |
| S (Sulfur) | 0.030 | - |
| Si (Silicon) | No specified limit | Typically 0.15–0.35 for deoxidation |
| V (Vanadium) | No specified limit | Not required for PSL1 |
| Nb (Niobium) | No specified limit | Not required for PSL1 |
| Ti (Titanium) | No specified limit | Not required for PSL1 |
GB/T 9711-2011 L175 PSL1 SSAW Pipeline Steel Thermal & Electrical Physical Properties
The following physical property values are typical for carbon-manganese steel and are not specified in GB/T 9711-2011. They may be used for design and modelling purposes. Actual values depend on the exact composition and heat treatment condition. Provided data correspond to room temperature unless otherwise noted.
| Property | Typical Value | Unit | Conditions / Remarks |
|---|---|---|---|
| Density (ρ) | 7.85 | g/cm³ | Room temperature |
| Modulus of Elasticity (E) | 210 | GPa | Tensile modulus |
| Shear Modulus (G) | 80 | GPa | Calculated |
| Poisson's Ratio (ν) | 0.30 | - | In elastic range |
| Thermal Expansion (α) | 12.0 × 10-6 | K-1 | 20 – 100 °C |
| Thermal Conductivity (λ) | 50 | W/(m·K) | At 20 °C |
| Specific Heat Capacity (c) | 500 | J/(kg·K) | At 20 – 100 °C |
| Electrical Resistivity (ρe) | 0.16 | μΩ·m | At 20 °C |
GB/T 9711-2011 L175 PSL1 SSAW Pipeline Steel Mechanical Properties
Mechanical properties of L175 PSL1 welded pipe as per GB/T 9711-2011, Table 9. Testing is performed on a transverse strip specimen representing the pipe body weld zone. The yield strength is the lower yield (ReH), tensile strength (Rm) is the maximum tensile load, and elongation is measured on a gauge length of 50 mm (A50) or equivalent. Bend test is carried out with a mandrel diameter equal to the specimen thickness, requiring no visible cracks after 180° bending.
| Property | Standard Value | Unit | Test Conditions |
|---|---|---|---|
| Yield Strength (ReH) | 175 – 310 | MPa | Transverse specimen at room temperature |
| Tensile Strength (Rm) | ≥ 310 | MPa | Transverse specimen at room temperature |
| Elongation (A) | ≥ 22 * | % | 50 mm gauge length (or proportional); *minimum value may be calculated by formula for other specimen dimensions |
| Bend Test (180°) | No cracks | - | Mandrel diameter = specimen thickness, ambient temperature |
GB/T 9711-2011 L175 PSL1 SSAW Pipeline Steel Completely Equivalent Material Standards & Substitute Grades
| Country / Region | Standard | Designation | Remarks |
|---|---|---|---|
| China | GB/T 9711-2011 | L175 PSL1 | Original standard; spiral or longitudinal submerged arc welded pipe |
| International | ISO 3183:2007 | L175 PSL1 | Technically identical to GB/T 9711-2011 |
| USA | API 5L (45th Ed.) | L175 PSL1 | Equivalent grade in API 5L/ISO harmonized system |
| Europe | EN ISO 3183:2012 | L175 PSL1 | European adoption of ISO 3183 |
GB/T 9711-2011 L175 PSL1 SSAW Pipeline Steel Application Introduction
L175 PSL1 spiral welded pipe is primarily used in non-sour, low-risk pipeline environments where the cost advantage of spiral pipe and moderate strength are favorable. Typical application scenarios include water transmission lines, low-pressure natural gas distribution, sewage systems, and structural pilings.
Product Applications: Spiral submerged arc welded (SSAW) pipes in long lengths (up to 12 m), Line pipes with external anti-corrosion coating (3LPE, FBE, etc.), Casing and conductor pipes, Structural hollow sections
Processed into products: Pipe sections for buried pipelines, Cold-formed or induction bends for pipeline routing, Welded joints (butt-welded, flanged), Piping spools for onshore static equipment
Application industries: Oil & Gas (gathering lines, flowlines, low-pressure transport), Water & Wastewater Utilities (transmission mains), Civil Engineering & Construction (structural pipe piles, foundation piles), Mining (slurry and water conveyance)
GB/T 9711-2011 L175 PSL1 SSAW Pipeline Steel Closely Similar Substitute Materials
| Country / Region | Standard | Designation | Remarks |
|---|---|---|---|
| International | ISO 3183:2007 | L210 PSL1 | Next higher strength grade (min YS 210 MPa); similar weldability, slightly higher Mn possible |
| International | API 5L | Grade A (L210) | Comparable pipeline steel; min YS 210 MPa, often used in low-pressure systems |
| China | GB/T 8163-2018 | Q235B | Mild structural steel; similar strength range, but not optimized for linepipe specifications |
| Europe | EN 10224 | L235 | Water pipe steel; higher strength but overlapping application area |
Notes:
PSL1 requirements do not mandate fracture toughness testing (Charpy impact), leaving it to the purchaser's discretion unless specified in the purchase order. For sour service or low-temperature applications, a PSL2 grade (e.g., L245N, L290N) with mandatory toughness and tighter chemistry should be considered. The pipe manufacturing standard also covers hydrostatic testing, dimensional tolerances, and non-destructive inspection of the weld seam in accordance with GB/T 9711.
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