Product Overview
Super 13Cr is a supermartensitic stainless steel predominantly designated as UNS S41426 (along with the associated variant UNS S41425). Classified under ISO 13680 / API 5CRA as Group 1 Category 13-5-2, this corrosion-resistant alloy is engineered specifically for seamless oil country tubular goods including casing, tubing, coupling stock, and accessory materials. It is supplied in a quenched and tempered condition across multiple strength grades, such as 95 ksi and 110 ksi, to withstand demanding oilfield service in carbon dioxide-containing environments accompanied by limited hydrogen sulfide.
Product Specifications
| Parameter | Value | Unit |
|---|---|---|
| Product | Super 13Cr | – |
| Grade / Model | Super 13Cr (UNS S41425 / S41426) | – |
| Standard | ISO 13680 / API 5CRA Category 13-5-2 (Group 1) | – |
| Material | Martensitic (supermartensitic) stainless steel | – |
| Product Form | Seamless OCTG tubing / casing (and accessory material) | – |
| Delivery Condition | Quenched and tempered | – |
Standards & Designations
| Country / Region | System / Standard / Manufacturer | Designation | Designation Type | Relationship | Applicable Scope | Source |
|---|---|---|---|---|---|---|
| International | ISO 13680 / API 5CRA | Category 13-5-2 (Group 1) | Classification | Confirmed | Martensitic CRA seamless OCTG | [S2], [S3], [S5], [S6] |
| USA | UNS | S41426 | Primary Grade | Confirmed | Super 13Cr OCTG | [S2], [S3], [S6] |
| USA | UNS | S41425 | Primary Grade | Confirmed | Associated Super 13Cr | [S1], [S4] |
| Europe | EN | 1.4415 / X2CrNiMoV13-5-2 | Material Number | Confirmed Equivalent | Bars / pipes | [S4] |
| Manufacturer | Nippon Steel | SM13CRS | Manufacturer Grade | Manufacturer Grade | Proprietary OCTG | [S3] |
Chemical Composition
UNS S41426 / ISO 13680 Category 13-5-2 (Seamless OCTG)
| C | Cr | Ni | Mo | Mn | Si | P | S | Ti | V |
|---|---|---|---|---|---|---|---|---|---|
| ≤0.03 | 11.50-13.50 | 4.50-6.50 | 1.50-3.00 | ≤0.50 | ≤0.50 | ≤0.020 | ≤0.005 | 0.01-0.50 | ≤0.50 |
Mechanical Properties
95 ksi Grade (Quenched & Tempered)
| Parameter | Value | Unit |
|---|---|---|
| Minimum Yield Strength | ≥655 | MPa |
| Minimum Tensile Strength | ≥724 | MPa |
| Hardness | ≤27-29 | HRC |
110 ksi Grade (Quenched & Tempered)
| Parameter | Value | Unit |
|---|---|---|
| Minimum Yield Strength | ≥755 | MPa |
| Minimum Tensile Strength | ≥862 | MPa |
| Hardness | ≤32-33 | HRC |
Impact Energy
| Parameter | Value | Unit |
|---|---|---|
| Impact Energy (Charpy-V, -10°C) | ≥60 | J |
Physical Properties
| Parameter | Value | Unit |
|---|---|---|
| Density | 7.7-7.8 | g/cm³ |
| Melting Point | 1400-1450 | °C |
| Elastic Modulus | 200 | GPa |
| Thermal Conductivity | 16-25 | W/(m·K) |
Dimensions & Tolerances
Commercial supply ranges for seamless OCTG tubing and casing include outside diameters spanning from 2-1/16″ to 10-3/4″ (with manufacturer capability extending up to 16″), wall thicknesses reaching up to 1.925″, and standard lengths covering R1, R2, and R3. Exact dimensional tolerances conform strictly to the governing edition of ISO 13680 / API 5CRA specified at the time of order placement.
Manufacturing & Supply
| Attribute | Details |
|---|---|
| Manufacturing Method | Steelmaking by electric furnace (EF) or basic oxygen furnace (BOF) producing fine-grained fully killed billets, followed by traditional hot tube seamless pipe making. |
| Delivery Condition | Quenched and tempered per ISO 13680 / API 5CRA Group 1 Category 13-5-2. |
| Available Product Forms | Seamless OCTG tubing and casing, coupling stock, accessory material, and associated bar forms. |
| Commercial Size Ranges | Outer diameter ranges from 2-1/16 inches to 10-3/4 inches (CRA example) or 2-3/8 inches to 16 inches (Nippon SM13CRS), with wall thicknesses up to 1.925 inches and lengths in R1, R2, and R3. |
Heat Treatment
Delivery condition under ISO 13680 / API 5CRA and manufacturer practice is quenched and tempered. Recommended processing parameters from manufacturer guidance for Super 13Cr / 1.4415 include quenching at 950 to 1050 degrees Celsius and tempering at 600 to 650 degrees Celsius.
Inspection & Quality
Manufactured based on API 5CT / ISO 11960 and API 5CRA / ISO 13680 standards.
Key Features & Advantages
| Short Title | Explanation |
|---|---|
| Enhanced Corrosion Resistance | Nickel and molybdenum additions provide superior resistance to carbon dioxide (CO2), chlorides, and limited hydrogen sulfide relative to standard 13Cr alloys. |
| High Strength Grades | Supplied in verified 95 ksi and 110 ksi strength grades with strict microstructural control. |
Applications
| Short Title | Explanation |
|---|---|
| OCTG Tubing & Casing | Utilized for oil and gas extraction, production strings, and well casings in corrosive environments. |
| Completion & Downhole Accessories | Applied in liners, base pipe for sand screens, packers, mandrels, drill collars, and subsea completion accessories. |
Packing & Delivery
Standard export packing suitable for seamless OCTG tubing and casing is applied to protect material during transportation.
Important Notes
Catalog identity references ISO 13680 Group 2, but verified sources and the standard define Group 1 as martensitic and Group 2 as duplex; Super 13Cr belongs strictly to Group 1 martensitic stainless steels. The 95 ksi condition is recommended for limited sour service under NACE MR0175 / ISO 15156 up to a 1.5 psi H2S partial pressure limit at pH 3.5 or greater, whereas the 110 ksi grade is not recommended for sour service.
