X46/L320 Pipeline Steel
(GB/T 9711 · ISO 3183 · API 5L X46)PSL1 Quality Min Yield ≥320 MPa (46 ksi) ISO 3183 X46/L320 / API 5L X46
X46/L320 pipeline steel conforms to Chinese standard GB/T 9711 (PSL1), international standard ISO 3183 X46/L320 and API 5L X46. It offers good strength (minimum yield 320 MPa / 46 ksi) with excellent weldability and toughness, widely used for high-pressure long-distance oil & gas transmission pipelines, offshore pipelines, and demanding structural applications.
🌍 STANDARD CROSS REFERENCE WITH CHEMICAL ELEMENTS (max %)
🇨🇳 CHINA
GB/T 9711
L320/X46
PSL1 / X46 equivalent
🧪 Chemical Elements (max %):
C: ≤0.26%
Mn: ≤1.40%
P: ≤0.030%
S: ≤0.030%
Cu: ≤0.50%
Ni: ≤0.50%
Cr: ≤0.50%
Mo: ≤0.15%
d: Total Nb+V+Ti ≤0.15% | B ≤0.001% (residual)
🌐 INTERNATIONAL
ISO 3183
X46/L320
PSL1 / Class X46
🧪 Chemical Elements (max %):
C: ≤0.26%
Mn: ≤1.40%
P: ≤0.030%
S: ≤0.030%
Cu: ≤0.50%
Ni: ≤0.50%
Cr: ≤0.50%
Mo: ≤0.15%
Nb+V+Ti ≤0.15% | B ≤0.001%
🇺🇸 USA
API 5L
X46
PSL1 / Grade X46
🧪 Chemical Elements (max %):
C: ≤0.28%¹
Mn: ≤1.40%
P: ≤0.030%
S: ≤0.030%
Cu: ≤0.50%
Ni: ≤0.50%
Cr: ≤0.50%
Mo: ≤0.15%
¹ For seamless C≤0.28%, for welded C≤0.24%. Nb+V+Ti ≤0.15%.
Designation Meaning: X = API grade prefix (yield strength in ksi) | 46 = Minimum yield strength 46 ksi (320 MPa) | L = Line pipe / 320 = Minimum yield strength (MPa)
🔬 Chinese grade pipeline steel PSL1 L320/X46 chemical composition a,g & Mechanical and technological properties of steel plates 🔍 PSL1 L320/X46 Approaching Grade Lookup Table →
Designation Method: The steel grade consists of three parts: the first letter of "Line" representing the pipeline, the specified minimum yield strength, and the delivery condition (applicable only to PSL2). Example: L320/X46.
L — Line pipe prefix; 320 — Minimum yield strength (MPa); X46 — API 5L grade (46 ksi yield strength).
📌 Application Fields — Pipeline & Oil & Gas Transmission
✔ High-pressure Oil & Gas Long-distance Pipelines
✔ Offshore Subsea Pipelines
✔ City Gas High-pressure Networks
✔ Industrial Water / Slurry Transport
✔ Structural Pipes & Piling
✔ Chemical Fluid Transmission Lines
✔ Mining & Slurry Transport
📦 Supply Range — Available Dimensions
📐 Outer Diameter (OD)
Seamless Pipe: 21.3mm - 610mm
Welded Pipe (LSAW/SSAW/ERW): 219mm - 1220mm
Steel Plate: 6mm - 40mm thickness
📏 Wall Thickness
Pipe: 2.0mm - 40mm
Plate: 2.0mm - 40mm
Custom thickness available
📏 Length
Standard: 6m, 12m, 18m
Custom: 1m - 18m
🔧 Product Forms
✔ Seamless / LSAW / SSAW / ERW Pipe
✔ Steel Plate & Coil
✔ Custom cut-to-size pieces
🧪 PSL1 Chemical Composition (GB/T 9711 / ISO 3183 L320/X46)
| Grade | Cᵇ ≤ | Mnᵇ ≤ | P ≤ | S ≤ | V | Nb | Ti | Cu ≤ | Ni ≤ | Cr ≤ | Mo ≤ |
|---|---|---|---|---|---|---|---|---|---|---|---|
| L320/X46 | ≤0.26 | ≤1.40 | ≤0.030 | ≤0.030 | d | d | d | 0.50 | 0.50 | 0.50 | 0.15 |
Notes:
a. The maximum content of copper is 0.50%; the maximum content of nickel is 0.50%; the maximum content of chromium is 0.50%; and the maximum content of molybdenum is 0.15%.
b. For every 0.01% decrease in carbon content compared to the maximum specified carbon content, the manganese content may be 0.05% higher than the maximum specified manganese content. However, for L245/B, L290/X42, L320/X46, and L360/X52, the maximum manganese content should not exceed 1.65%; for L390/X56, L415/X60, and L450/X65, the maximum manganese content should not exceed 1.75%; and for L485/X70, the manganese content should not exceed 2.00%.
c. Unless otherwise agreed, the total content of niobium and vanadium shall not exceed 0.06%.
d. The total content of niobium, vanadium, and titanium should not exceed 0.15%.
e. Unless otherwise agreed.
f. Unless otherwise agreed, the total content of niobium, vanadium, and titanium shall not exceed 0.15%.
g. Unless otherwise specified, boron should not be intentionally added, and the residual boron content should not exceed 0.001%.
a. The maximum content of copper is 0.50%; the maximum content of nickel is 0.50%; the maximum content of chromium is 0.50%; and the maximum content of molybdenum is 0.15%.
b. For every 0.01% decrease in carbon content compared to the maximum specified carbon content, the manganese content may be 0.05% higher than the maximum specified manganese content. However, for L245/B, L290/X42, L320/X46, and L360/X52, the maximum manganese content should not exceed 1.65%; for L390/X56, L415/X60, and L450/X65, the maximum manganese content should not exceed 1.75%; and for L485/X70, the manganese content should not exceed 2.00%.
c. Unless otherwise agreed, the total content of niobium and vanadium shall not exceed 0.06%.
d. The total content of niobium, vanadium, and titanium should not exceed 0.15%.
e. Unless otherwise agreed.
f. Unless otherwise agreed, the total content of niobium, vanadium, and titanium shall not exceed 0.15%.
g. Unless otherwise specified, boron should not be intentionally added, and the residual boron content should not exceed 0.001%.
⚡ PSL1 Mechanical Properties (L320/X46)
| Steel grade | Total elongation strength a,b Rt0.5/MPa | tensile strength a,b Rm/MPa | Elongation after fracture c/% A | 180° Bending test (a-Sample thickness D-Bending indenter diameter) |
|---|---|---|---|---|
| L320/X46 | ≥320 | ≥435 | ≥20 | D=2a |
Remarks:
a. When selecting grades from the table, the buyer and supplier shall negotiate and determine a suitable range of tensile properties to ensure that the tensile properties of the finished steel pipes meet the requirements of the corresponding standards.
b. The tensile test specimen orientation listed in the table shall be determined by the purchaser and shall be specified in the contract. Generally, the tensile test specimen orientation is the transverse direction of the corresponding steel pipe.
c. According to the standard gauge length test, a proportional gauge length test can also be used when the user has special requirements. In case of disputes, arbitration will be conducted using a specimen with a gauge length of 50 mm and a width of 38 mm. The minimum elongation after fracture when the gauge length is 50 mm is calculated using this formula: A50mm = 1940 * S0^0.2 / Rm^0.9. S0: Original cross-sectional area of the tensile specimen, in square millimeters. Rm: Specified minimum tensile strength, in megapascals. Note 1: For round bar specimens, S0 is 130 mm² for specimens with diameters of 12.7 mm and 8.9 mm; S0 is 65 mm² for specimens with a diameter of 6.4 mm. Note 2: For full-thickness rectangular specimens, take the smaller of a) 485 mm² and b) specimen cross-sectional area (nominal thickness * specimen width), rounded to the nearest 10 mm².
a. When selecting grades from the table, the buyer and supplier shall negotiate and determine a suitable range of tensile properties to ensure that the tensile properties of the finished steel pipes meet the requirements of the corresponding standards.
b. The tensile test specimen orientation listed in the table shall be determined by the purchaser and shall be specified in the contract. Generally, the tensile test specimen orientation is the transverse direction of the corresponding steel pipe.
c. According to the standard gauge length test, a proportional gauge length test can also be used when the user has special requirements. In case of disputes, arbitration will be conducted using a specimen with a gauge length of 50 mm and a width of 38 mm. The minimum elongation after fracture when the gauge length is 50 mm is calculated using this formula: A50mm = 1940 * S0^0.2 / Rm^0.9. S0: Original cross-sectional area of the tensile specimen, in square millimeters. Rm: Specified minimum tensile strength, in megapascals. Note 1: For round bar specimens, S0 is 130 mm² for specimens with diameters of 12.7 mm and 8.9 mm; S0 is 65 mm² for specimens with a diameter of 6.4 mm. Note 2: For full-thickness rectangular specimens, take the smaller of a) 485 mm² and b) specimen cross-sectional area (nominal thickness * specimen width), rounded to the nearest 10 mm².
🏭 Smelting Method & Delivery Condition
Smelting Method
Steel shall be smelted in an oxygen converter or electric furnace. For PSL1, rimming, killed or semi-killed steel permitted as per standard.
Delivery Condition
Steel plates/pipes are delivered in hot-rolled, normalized, normalized rolled, or thermomechanically rolled condition as per GB/T 9711 / API 5L.
🛠️ Customization Services
✅ Special length tolerances, cut-to-length
✅ Additional NDT (UT/MT/RT)
✅ Anti-corrosion coatings (3PE, FBE, epoxy)
✅ Impact toughness (-20°C / -40°C Charpy V-notch)
✅ Sour service (H₂S resistant) optional
✅ Third-party inspection (BV, SGS, Lloyds)
❓ Frequently Asked Questions
📧 Request a Quote / Inquiry Form
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