L245/B Pipeline Steel

(GB/T 9711 · ISO 3183 · API 5L Gr.B)
PSL1 Quality Min Yield ≥245 MPa ISO 3183 L245/B / API 5L Gr.B

L245/B pipeline steel conforms to Chinese standard GB/T 9711 (PSL1), international standard ISO 3183 L245/B and API 5L Grade B. It offers good strength (minimum yield 245 MPa) with excellent weldability and toughness, widely used for oil & gas transmission pipelines, water pipelines, and structural applications.

🌍 STANDARD CROSS REFERENCE WITH CHEMICAL ELEMENTS (max %)
🇨🇳 CHINA
GB/T 9711
L245/B
PSL1 / Grade B equivalent
🧪 Chemical Elements (max %):
C: ≤0.26%
Mn: ≤1.20%
P: ≤0.030%
S: ≤0.030%
Cu: ≤0.50%
Ni: ≤0.50%
Cr: ≤0.50%
Mo: ≤0.15%
c: Nb+V ≤0.06% | d: Nb+V+Ti ≤0.15% | g: B ≤0.001% (residual)
🌐 INTERNATIONAL
ISO 3183
L245/B
PSL1 / Class B
🧪 Chemical Elements (max %):
C: ≤0.26%
Mn: ≤1.20%
P: ≤0.030%
S: ≤0.030%
Cu: ≤0.50%
Ni: ≤0.50%
Cr: ≤0.50%
Mo: ≤0.15%
Nb+V ≤0.06% | Nb+V+Ti ≤0.15% | B ≤0.001%
🇺🇸 USA
API 5L
Gr.B
PSL1 / Grade B
🧪 Chemical Elements (max %):
C: ≤0.26%¹
Mn: ≤1.20%²
P: ≤0.030%
S: ≤0.030%
Cu: ≤0.50%
Ni: ≤0.50%
Cr: ≤0.50%
Mo: ≤0.15%
¹ For seamless C≤0.26%, for welded C≤0.22%. ² Mn max 1.20% for Gr.B. Nb+V ≤0.06% if agreed.
Designation Meaning: L = Line pipe | 245 = Minimum Yield Strength (MPa) | B = Grade identification (ISO 3183 / API 5L)
🔬 Chinese grade pipeline steel PSL1 L245/B chemical composition a,g & Mechanical and technological properties of steel plates 🔍 PSL1 L245/B 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: L245/B.

L — Represents the first letter of "Line" for the pipeline;
245 — Minimum yield strength specified (MPa);
B — Grade classification according to ISO 3183 / API 5L, ensuring mechanical performance.

📌 Application Fields — Pipeline & Oil & Gas Transmission

✔ Oil & Gas Long-distance Pipelines
✔ City Gas Distribution Networks
✔ Industrial Water / Slurry Transport
✔ Structural Pipes & Piling
✔ Chemical Fluid Transmission Lines
✔ Water Supply & Drainage Systems
✔ 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 L245/B)

Grade Cᵇ ≤ Mnᵇ ≤ P ≤ S ≤ V Nb Ti Cu ≤ Ni ≤ Cr ≤ Mo ≤
L245/B ≤0.26 ≤1.20 ≤0.030 ≤0.030 c c 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%.

PSL1 Mechanical Properties (L245/B)

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)
L245/B ≥245 ≥415 ≥21 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.

🏭 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)
✅ Intermediate grade negotiation per ISO 3183
✅ Third-party inspection (BV, SGS, Lloyds)

Frequently Asked Questions

1. Is L245/B equivalent to API 5L Grade B?
Yes, ISO 3183 L245/B and API 5L Grade B have identical minimum yield strength (245 MPa) and comparable tensile requirements. Chemical composition limits are consistent for PSL1.
2. What is the typical MOQ?
MOQ normally 10 tons, but we accept trial orders of smaller quantities. Contact us for flexible solutions.
3. Can L245/B be used for low-temperature service?
Standard PSL1 offers ambient temperature properties. For -20°C or -40°C impact values, customized microalloying is available.
4. Delivery time?
Stock sizes: 30-35 days. Custom orders: 40-45 days. Lead time confirmed upon order.
5. Are mill certificates provided?
Yes, EN 10204 Type 3.1 or 3.2 certificates with chemical and mechanical test reports are supplied. Third-party inspection available.

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