When does 13Cr stop being enough?

When H₂S is present (SSC), when chloride levels and temperature combine toward pitting/SCC limits, or in strong organic-acid jobs — then super 13Cr, duplex 22Cr or nickel alloys take over.

Is L80 13Cr the same as plain L80?

No. Plain L80 is carbon/low-alloy steel controlled by strength; L80 Type 13Cr is a specified 12–14% Cr stainless chemistry at the same yield window. Certificates must say “13Cr”.

Grades · Pipe & Tube Steel · API L80 13Cr Casing

API L80 13Cr Casing

Data verified

L80 13Cr is the corrosion-resistant workhorse of the CRA casing family: a true martensitic stainless chemistry written into API 5CT (one of the few 5CT grades with a specified composition), built for sweet CO₂ corrosion that would pit and thin carbon-steel tubing in a few years.

Hardness≤23.0 HRC

AISIAPI 5CT L80 Type 13Cr

GBL80-13Cr (GB/T 19830)

CategoryPipe & Tube Steel

Chemical composition

Element	Content (%)
C	0.15–0.22
Si	≤1.00
Mn	0.25–1.00
P	≤0.020
S	≤0.010
Cr	12.00–14.00
Ni	≤0.50
Cu	≤0.25

Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.

Properties

Yield strength	552–655 MPa (80–95 ksi)
Tensile strength	≥655 MPa (95 ksi)
Hardness	≤23.0 HRC
Density	7.85 g/cm³

Heat treatment

Quenched and tempered martensitic stainless; hardness capped at 23 HRC for the grade’s CO₂-service envelope.

Equivalent grades

Standard	Designation
aisi	API 5CT L80 Type 13Cr
gb	L80-13Cr (GB/T 19830)

Compare side by side: API L80 13Cr Casing vs API L80 Casing

Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.

Applications & Processing

Applications: CO₂-corrosive (sweet) production tubing and casing, gas wells with wet CO₂, geothermal production strings, water injection service.

Processing: Not weldable in the field sense — premium threaded connections only, with dope and handling care for the stainless surface. Watch the envelope: chlorides plus temperature, or any H₂S, can push the job to super-13Cr or duplex.

FAQ

When does 13Cr stop being enough?: When H₂S is present (SSC), when chloride levels and temperature combine toward pitting/SCC limits, or in strong organic-acid jobs — then super 13Cr, duplex 22Cr or nickel alloys take over.
Is L80 13Cr the same as plain L80?: No. Plain L80 is carbon/low-alloy steel controlled by strength; L80 Type 13Cr is a specified 12–14% Cr stainless chemistry at the same yield window. Certificates must say “13Cr”.

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Source: API 5CT published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.