L80-13Cr comprehensively outperforms L80-9Cr in terms of corrosion resistance, alloy content, and applicable operating conditions. Although both belong to the L80 steel grade, L80-13Cr-thanks to its higher chromium, molybdenum, and nickel content-is specifically engineered for more severe corrosive environments.
Avoid Project Delays: Ready Stock of API 5CT L80-9Cr & 13Cr Available.
API 5CT L80-9Cr & 13Cr casing Chemical Composition Comparison
| Element (wt%) | L80-9Cr | L80-13Cr |
| Carbon (C) | ≤ 0.15 | 0.15 ~ 0.22 |
| Chromium (Cr) | 8.00 ~ 10.00 | 12.00 ~ 14.00 |
| Molybdenum (Mo) | 0.90 ~ 1.10 | Not Specified (Typical < 0.05) |
| Manganese (Mn) | 0.30 ~ 0.60 | 0.25 ~ 1.00 |
| Silicon (Si) | ≤ 1.00 | ≤ 1.00 |
| Nickel (Ni) | ≤ 0.50 | ≤ 0.50 |
| Phosphorus (P) | ≤ 0.020 | ≤ 0.020 |
| Sulfur (S) | ≤ 0.010 | ≤ 0.010 |
| Copper (Cu) | ≤ 0.25 | ≤ 0.25 |
API 5CT L80-9Cr & 13Cr OCTG Mechanical Properties Comparison
| Property Item | L80-9Cr | L80-13Cr |
| Yield Strength (Rt0.5) | 552 ~ 655 MPa (80~95 ksi) | 552 ~ 655 MPa (80~95 ksi) |
| Tensile Strength (Rm) | ≥ 655 MPa (95 ksi) | ≥ 655 MPa (95 ksi) |
| Elongation (A) | Per API 5CT Formula | Per API 5CT Formula |
| Max Hardness | ≤ 23 HRC | ≤ 23 HRC |
| Hardness Variation | ≤ 6.0 HRC (Cross-section) | ≤ 6.0 HRC (Cross-section) |
| Microstructure | Tempered Martensite | Tempered Martensite |
API 5CT L80-9Cr & 13Cr Seamless Oil Casing Pipe Corrosion Performance & Service Limits
| Parameter | L80-9Cr | L80-13Cr |
| Primary Resistance |
CO2CO2 Corrosion |
CO2CO2 Corrosion |
|
CO2CO2 Partial Pressure (PCO2PCO2 ) |
Moderate (Suggested < 2 psi) | High (Can exceed 30 psi) |
|
H2SH2S Partial Pressure (PH2SPH2S ) |
Trace (< 0.01 psi) | Very Low (< 0.05 psi); prone to SSC |
| Chloride (
Cl−Cl− ) Conc. |
Sensitive (Risk of pitting) | Sensitive (Film breaks at high conc.) |
| Max Service Temp. | ~ 120°C - 150°C | ~ 150°C - 180°C |
| pH Environment | > 4.5 | > 3.5 |
| Passive Film Stability | Moderate; Cr level is below "stainless" threshold | High; Cr >12% forms stable
Cr2O3Cr2O3 |
| Molybdenum (Mo) Role | Improves pitting resistance | Relies on Cr (unless Super 13Cr) |
API 5CT L80-9Cr & 13Cr oil well casing Physical & Manufacturing Characteristics
| Item | L80-9Cr | L80-13Cr |
| Heat Treatment | Quench + Temper (Q+T) | Quench + Temper (Q+T) |
| Density (
ρρ ) |
~ 7.75
g/cm3g/cm3 |
~ 7.70
g/cm3g/cm3 |
| Elastic Modulus (E) | ~ 210 GPa | ~ 200 GPa |
| Thermal Expansion | Slightly higher than carbon steel | Significantly lower than carbon steel |
| NDT Requirements | Full length EMI / UT | Full length EMI / UT |
| Thread Connection | Usually Premium Connections | Usually Premium Connections |
| Galling Resistance | Moderate | Poor (High Cr is prone to galling) |
| Relative Cost | Lower (Economic alternative) | Higher (Standard solution) |
GNEE API 5CT casing and tubing in stock
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Zero-Defect Commitment: 100% Full-Body UT & EMI Tested.
FAQ
What is L80 steel?
Low Alloy Steel
L80 is a low-alloy steel used primarily in oil and gas applications, particularly for casing and tubing.
What is L80 equivalent to?
L80 is usually used in wells with sour (hydrogen sulfide) environments, casing, production tubing, coupling stock, pup joints, and various downhole accessories. L80 (API 5CT) is a medium carbon steel and is equivalent to SAE 4140.
What is the meaning of L80?
L80 : It means that a minimum of 80% of the luminous flux will be maintained for a defined period given the maximum ambient temperature.