What X13CrMo12 is
X13CrMo12 is a hardenable stainless steel from the 12% chromium martensitic family. Chromium between 11.50 and 12.50% is enough to form a passive film, so the steel stands up to water, steam and mildly corrosive media. Molybdenum between 0.40 and 0.60% raises strength and creep resistance at elevated temperature and improves pitting resistance compared with a plain 12% chromium steel such as AISI 410. Carbon is kept low, at 0.07 to 0.12%, which gives up some hardness in return for toughness, better weldability and more predictable behaviour in thick sections.
For a buyer, the grade sits between a plain 13% chromium stainless and the higher alloy creep resistant turbine steels. It gets specified when a part has to run hot and wet but still be forged and machined in large sections at a reasonable cost. The steel air hardens, so section size and cooling rate matter, and heat treatment is planned around the real part geometry rather than a test coupon.
Equivalent and related grades
The designations below cover the same chemistry in different national systems. An equivalent means comparable composition and typical properties, not an identical specification. Name the governing standard on the purchase order.
| System | Designation | Note |
|---|---|---|
| Chemical name | X13CrMo12 | 12% Cr martensitic stainless with Mo |
| UNS | S41025 | Cross reference used on most export orders |
| China (GB/T 1221) | 1Cr12Mo · 12Cr12Mo | Closest domestic grade |
| Same family, no Mo | AISI 410 · X12Cr13 · 1.4006 | Lower strength at temperature |
| Same family, higher alloy | X20CrMoV11-1 · X22CrMoV12-1 | Chosen when creep duty is more severe |
If your drawing calls for a grade not listed here, send it over. Most 12% chromium martensitic specifications can be met from the same melt with an agreed chemistry restriction.
Chemical composition of X13CrMo12
Limits in weight percent, balance iron. Ladle analysis and product analysis are both reported on the mill certificate against the heat number.
| Element | Symbol | Minimum | Maximum |
|---|---|---|---|
| Carbon | C | 0.07 | 0.12 |
| Silicon | Si | — | 0.35 |
| Manganese | Mn | 0.30 | 0.60 |
| Phosphorus | P | — | 0.040 |
| Sulphur | S | — | 0.030 |
| Chromium | Cr | 11.50 | 12.50 |
| Molybdenum | Mo | 0.40 | 0.60 |
| Nickel | Ni | — | 0.60 |
| Copper | Cu | — | 0.50 |
| Aluminium | Al | — | 0.05 |
| Tin | Sn | — | 0.05 |
| Nitrogen | N | — | 0.08 |
Residual elements are held tighter than the table where a specification calls for it, for example a restricted phosphorus and sulphur aim for turbine and nuclear work. State the requirement at enquiry so it is written into the melt instruction.
Mechanical and physical data
Mechanical properties of X13CrMo12 depend on the tempering temperature. The bands below are indicative for the hardened and tempered condition in moderate sections. The values that count are the ones agreed at order and certified on the test report for your heat and your section size.
| Property | Typical value | Set by |
|---|---|---|
| Tensile strength, Rm | 620–850 MPa | Tempering temperature |
| Yield strength, Rp0.2 | 450–700 MPa | Tempering temperature |
| Elongation, A | 15–22% | Section size, test direction |
| Reduction of area, Z | 45–60% | Cleanliness, melting route |
| Impact energy, KV at 20 °C | 40–80 J | Tempering, grain size |
| Hardness, quenched and tempered | 200–270 HB | Tempering temperature |
| Hardness, annealed | max 220 HB | Annealing cycle |
| Property | Typical value |
|---|---|
| Density | 7.70 g/cm³ |
| Modulus of elasticity at 20 °C | 215 GPa |
| Thermal expansion, 20–400 °C | 11.5 × 10-6/K |
| Thermal conductivity at 20 °C | 25 W/(m·K) |
| Magnetic response | Ferromagnetic |
Melting and forging
X13CrMo12 is melted in an electric arc furnace and refined by vacuum oxygen decarburisation. That route is what makes low carbon achievable at 12% chromium without losing chromium to the slag. Electroslag remelting is added when the order calls for tighter cleanliness, less centreline segregation and better transverse properties, which is the usual choice for turbine discs, rotors and valve internals.
- EAF + VOD as the standard route for X13CrMo12 forgings
- ESR available for turbine, nuclear and critical valve work
- Open-die forging on hydraulic presses, forged from the ingot rather than cut from rolled bar
- Seamless ring rolling for rings, flanges and bearing races
- Forging reduction ratio agreed at order and recorded on the certificate
- Grain flow follows the part contour, which gives better fatigue performance than machining from plate
Heat treatment conditions
Jiangyin Jiangnan Metal delivers X13CrMo12 annealed, normalized, or quenched and tempered, as the customer specifies. The cycles below are the practice used in the works. They are adjusted for section size and for any acceptance values written into the order.
| Operation | Temperature | Cooling | Purpose |
|---|---|---|---|
| Forging | 1150–850 °C | Slow, controlled | Shape the part, refine the as-cast structure |
| Annealing | 750–800 °C | Furnace | Soften for machining, relieve stress |
| Normalizing | 950–1000 °C | Air | Uniform grain before hardening |
| Hardening | 950–1000 °C | Oil or air | Form martensite |
| Tempering | 650–750 °C | Air | Set final strength and toughness |
Tempering in the range that causes embrittlement is avoided, and every furnace charge is recorded with time, temperature and quench medium on the heat treatment chart supplied with the certificate.
Forged product forms in X13CrMo12
Everything below is forged to drawing. If the shape you need is not shown, it is quoted the same way. Send the drawing.
Size and weight range
| Form | Range |
|---|---|
| Single piece weight | 50 kg to 20 tonnes |
| Round bars and shafts | 80 to 1,200 mm diameter, up to 8,000 mm long |
| Hollow bars and sleeves | 200 to 2,000 mm outside diameter, 100 mm minimum bore |
| Rings and seamless rolled rings | up to 3,000 mm outside diameter, up to 1,000 mm height |
| Discs and blocks | up to 2,500 mm diameter, up to 800 mm thick |
| Machining allowance | Rough turned, proof machined or finish machined to drawing |
The limit for a given part depends on its shape and on the forging reduction ratio required. Treat the table as a starting point and confirm the specific piece.
Testing and certification
Every X13CrMo12 forging leaves the works with a certificate that ties the part back to its heat number, its heat treatment charge and its test results.
Non-destructive testing
- Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, to the quality class named on the order
- Magnetic particle inspection to ASTM E709 or the customer's procedure
- Dye penetrant inspection where geometry makes MPI impractical
- Hardness survey across the section
Destructive and chemical testing
- Tensile, impact and hardness testing on prolongations or sacrificial coupons
- Chemical analysis by spectrometer, ladle and product analysis both reported
- Grain size, macro-etch and non-metallic inclusion rating on request
- Intergranular corrosion testing where the specification calls for it
Documentation
- EN 10204 3.1 inspection certificate as standard
- EN 10204 3.2 certificate countersigned by SGS, BV, TUV or Lloyd's on request
- Heat treatment charts, UT reports and dimensional reports issued with the goods
- Third-party witness inspection accepted at the works
Where X13CrMo12 is used
The combination of 12% chromium, molybdenum and low carbon suits parts that see heat, moisture and load at the same time.
| Industry | Parts |
|---|---|
| Steam and gas turbines | Turbine wheels, discs, blades, vanes, impellers, blisks, rotor components |
| Valves | Valve spindles, stems, rods, bonnets, valve bodies, seat rings |
| Power generation | Feedwater pump parts, casings, sleeves, fasteners for hot service |
| Oil, gas and petrochemical | Pump shafts, compressor components, pressure-retaining parts |
| General engineering | Shafts, hubs, housings and bushings in hot water or steam duty |
How to order X13CrMo12 forgings
An enquiry is quoted fastest when it carries what the works needs to plan the ingot, the press and the furnace. Send whatever you have. A drawing is ideal, rough dimensions are enough to start.
- Drawing, or the rough dimensions with machining allowance
- Quantity, and whether repeat orders are expected
- Grade and the governing standard, if your specification names one
- Delivery condition: annealed, normalized, or quenched and tempered to stated properties
- Melting route, if ESR is required
- NDT scope and acceptance class
- Certificate type: EN 10204 3.1 or 3.2, and any third-party witness
- Destination port and required delivery date
Quotation is normally returned within 24 hours. Typical production lead time is 15 to 45 days depending on size, heat treatment and testing scope.
Questions and answers about X13CrMo12
What is X13CrMo12 steel?
X13CrMo12 is a martensitic stainless steel containing 11.50–12.50% chromium and 0.40–0.60% molybdenum, with carbon held to 0.07–0.12%. The chromium gives it corrosion and oxidation resistance, the molybdenum improves strength and creep resistance at elevated temperature, and the low carbon keeps it tough and weldable for a martensitic grade. It is used for steam and gas turbine components, valve internals and other parts working in hot water, steam and mildly corrosive service.
What is the equivalent grade of X13CrMo12?
X13CrMo12 is cross-referenced to UNS S41025 and to the Chinese grade 1Cr12Mo (12Cr12Mo in GB/T 1221). It belongs to the same 12% chromium martensitic family as AISI 410 and X12Cr13 (1.4006), but differs from them by its deliberate molybdenum addition of 0.40–0.60%. Cross-references indicate comparable chemistry, not identity, so Jiangyin Jiangnan Metal recommends that the governing standard and acceptance criteria are stated on the purchase order.
What is the chemical composition of X13CrMo12?
The X13CrMo12 composition supplied by Jiangyin Jiangnan Metal is C 0.07–0.12%, Si max 0.35%, Mn 0.30–0.60%, P max 0.040%, S max 0.030%, Cr 11.50–12.50%, Mo 0.40–0.60%, Ni max 0.60%, Cu max 0.50%, Al max 0.05%, Sn max 0.05% and N max 0.08%, with the balance iron. The ladle analysis and the product analysis are both reported on the mill certificate.
Which forged shapes can you make in X13CrMo12?
Jiangyin Jiangnan Metal produces X13CrMo12 as forged round, square and flat bars, shafts, hollow bars, sleeves, bushes, bushings, cylinders, barrels, casings, shells, hubs and housings, forged rings and seamless rolled rings, discs, blocks and plates, gas turbine wheels, blades, vanes, turbine discs, impellers and blisks, and valve spindles, stems, bonnets and valve bodies. Parts are forged to drawing, so shapes outside this list are quoted the same way.
What size and weight of X13CrMo12 forging can you produce?
Jiangyin Jiangnan Metal forges X13CrMo12 in single pieces from about 50 kg to 20 tonnes: bars up to about 1,200 mm diameter and 8,000 mm long, rings and seamless rolled rings up to about 3,000 mm outside diameter, and discs up to about 2,500 mm diameter. The practical limit for any given part depends on its shape and the forging reduction ratio required, so send the drawing for confirmation.
Which melting route is used for X13CrMo12?
X13CrMo12 is melted by electric arc furnace with vacuum oxygen decarburisation (EAF + VOD). Electroslag remelting (ESR) is offered when the order calls for tighter cleanliness, lower segregation and better transverse properties, which is usual for turbine rotors, discs and valve internals.
In what heat treatment condition is X13CrMo12 delivered?
X13CrMo12 forgings are delivered annealed, normalized, or quenched and tempered, according to the customer's specification. Properties in the hardened and tempered condition are governed mainly by the tempering temperature, so the required strength, hardness or impact values should be stated at enquiry and they are then certified on the test report.
What non-destructive testing do you carry out on X13CrMo12 forgings?
X13CrMo12 forgings are ultrasonically tested to EN 10228-3, SEP 1921 or ASTM A388, to the quality class stated on the order. Magnetic particle or dye penetrant inspection, hardness survey, mechanical testing, chemical analysis and dimensional inspection are carried out as required, and the results are issued on the certificate.
What certificates are issued with X13CrMo12 forgings?
Jiangyin Jiangnan Metal issues an EN 10204 3.1 inspection certificate as standard, and an EN 10204 3.2 certificate countersigned by a third party such as SGS, BV, TUV or Lloyd's when the order requires it. The certificate covers heat number, chemical analysis, heat treatment record, mechanical test results and NDT results.
How do I get a price for an X13CrMo12 forging?
Send the drawing or the rough dimensions, the quantity, the delivery condition and the testing and certification you need to sales@steelforgepieces.com, or call +86 189 2135 9659. Jiangyin Jiangnan Metal normally returns a quotation within 24 hours; typical production lead time is 15 to 45 days depending on size, heat treatment and testing scope.
About the supplier
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. The works forges bars, shafts, hollow bars, sleeves, seamless rolled rings, discs and blocks in carbon steel, alloy steel, tool steel, stainless steel and nickel alloys, supplying turbine, valve, power generation, oil and gas and general engineering customers worldwide. X13CrMo12 is one of the martensitic stainless grades held as a regular forging item.