Stainless Steel 1.4938
EN 1.4938
1.4938 (X12CrNiMoV12-3) is a nickel-modified 12% Cr martensitic turbine steel with Mo and V additions, supplied in the EN conditions +A, +U, +QT and +QT1100.
Reference datasheet — 1.4938 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the +QT condition
1.4938 tempers and conditions
1.4938 is supplied in 4 conditions, soft to hard. +QT is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Delivery condition for machining, deep drilling and forging stock before final quench and temper. | 520 | 790 | 20 | 22 HRC | — |
Hot rolled | Semi-finished bar or forging supplied without final heat treatment, to be quenched and tempered by the user. | 750 | 1,050 | 14 | 34 HRC | 2.8 % IACS |
+QTDefault Quenched and tempered | Standard supply condition for turbine rotors, discs, blades and high-temperature bolting up to ~550 °C. | 800 | 980 | 17 | 31 HRC | — |
Quenched and tempered at lower temperature, 1000–1200 MPa | Higher-strength temper for blades, small forgings and fasteners where strength outweighs impact toughness. | 930 | 1,100 | 14 | 36 HRC | — |
What is 1.4938?
1.4938 (X12CrNiMoV12-3) is a nickel-modified 12% Cr martensitic turbine steel with Mo and V additions, supplied in the EN conditions +A, +U, +QT and +QT1100. Engineers select it over standard 1.4923 for higher toughness and better through-hardenability in large rotor forgings, with default values of 800 MPa yield, 980 MPa tensile, 17% elongation and about 300 HB (31 HRC). Service is limited to roughly 550 °C, corrosion resistance is modest for a stainless (score 45), and welding requires preheat plus a mandatory post-weld temper. 1.4923 is the nearest lower-alloy alternative. 1.4938 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,420°C (2,588 °F). 1.4938 has a yield strength of 800 MPa (116 ksi) and a tensile strength of 980 MPa (142 ksi) — stronger than 96% of stainless steel grades. Elongation at break is 17% and the elastic modulus is 216 GPa (31.3 Msi).
What is 1.4938 used for?
- Large steam turbine rotors
- Turbine shafts
- High-temperature forged discs
- Power plant rotating components
Advantages
- High strength — 800 MPa (116 ksi), better than 96% of stainless steel grades
- High electrical conductivity — 2.9 % IACS, better than 87% of stainless steel grades
- Conducts heat well — 24 W/m·K (13.9 BTU/hr·ft·°F), better than 81% of stainless steel grades
Limitations
- Limited ductility — 17%, worse than 86% of stainless steel grades
- Difficult to weld — 35/100, worse than 86% of stainless steel grades
- Needs corrosion protection — 45/100, worse than 85% of stainless steel grades
- Limited formability — 25/100, worse than 78% of stainless steel grades
1.4938 properties
Typical room-temperature values for 1.4938-+QT; bars are the position among stainless steel grades.
Physical3
1.4938 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
1.4938 has a yield strength of 800 MPa (116 ksi) and a tensile strength of 980 MPa (142 ksi) — stronger than 96% of stainless steel grades. Elongation at break is 17% and the elastic modulus is 216 GPa (31.3 Msi).
Thermal6
1.4938 is rated for continuous service to 550°C (1,022 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), better than 81% of stainless steel grades. Thermal expansion is 10.5 µm/m·K (5.83 µin/in·°F).
Electrical3
1.4938 conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 85% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4938 takes about 55 MJ of energy and emits 4.3 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 55%.
Manufacturability8
1.4938's machinability is fair (38/100, better than 63% of stainless steel grades); weldability fair (35/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. 1.4938 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.4938
Is 1.4938 easy to machine?
Machine in the +A condition where possible; in +QT use rigid setups, sharp carbide inserts, low speed/high feed and copious coolant — work-hardens and produces stringy chips.
Can 1.4938 be welded?
Weldable with matching 12Cr filler or Ni-base consumables using 250–350 °C preheat, interpass control and a mandatory post-weld temper ~680–700 °C to restore HAZ toughness.
Can 1.4938 be formed, bent or molded?
Hot forge/upset at 1100–850 °C with slow controlled cooling; cold forming is limited to minor straightening because of high strength and low ductility.
1.4938 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C | 0.1 – 0.15 | 0.12 |
| Si | ≤ 0.5 | 0.3 |
| Mn | 0.3 – 0.8 | 0.55 |
| Pimpurity | ≤ 0.03 | |
| Simpurity | ≤ 0.02 | |
| Cr | 11 – 12.5 | 11.8 |
| Mo | 1.5 – 2 | 1.75 |
| Niraises hardenability and toughness vs 1.4923 | 2 – 3 | 2.5 |
| Vcarbide former for creep strength | 0.25 – 0.4 | 0.3 |
| Fe | balance |
What surface finishes work on 1.4938?
Passivate or nitride for wear/erosion; takes a fine polish, but no anodizing — thermal/erosion coatings are common on blade surfaces.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel 1.4938 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- X12CrNiMoV12-3
How much does 1.4938 cost?
1.4938 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
1.4938 — frequently asked
What is 1.4938 used for?
1.4938 is typically used for large steam turbine rotors, turbine shafts, high-temperature forged discs and power plant rotating components. In short: tougher than 1.4923; through-hardening rotor steel; 550 °C service limit.
What is the yield strength of 1.4938?
1.4938 has a typical yield strength of 800 MPa (116 ksi) and a tensile strength of 980 MPa (142 ksi) — stronger than 96% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is 1.4938 easy to machine?
Not especially — machinability is rated fair (38/100, better than 63% of stainless steel grades). Machine in the +A condition where possible; in +QT use rigid setups, sharp carbide inserts, low speed/high feed and copious coolant — work-hardens and produces stringy chips.
Can 1.4938 be welded?
With care — weldability is rated fair (35/100). Weldable with matching 12Cr filler or Ni-base consumables using 250–350 °C preheat, interpass control and a mandatory post-weld temper ~680–700 °C to restore HAZ toughness.
What surface finishes work on 1.4938?
Passivate or nitride for wear/erosion; takes a fine polish, but no anodizing — thermal/erosion coatings are common on blade surfaces.
Can 1.4938 be formed, bent or molded?
Hot forge/upset at 1100–850 °C with slow controlled cooling; cold forming is limited to minor straightening because of high strength and low ductility.
What is the maximum service temperature of 1.4938?
1.4938 is rated for continuous use to about 550°C (1,022 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 1.4938 cost?
1.4938 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- EN 10269 — Steels and nickel alloys for fasteners with specified elevated and/or low temperature properties — CEN (2013)
- DIN 17240 / EN 10302 — Creep-resisting steels for bolting and turbine components — DIN / CEN (2008)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- 12% Cr martensitic turbine steel datasheets (Böhler, Aubert & Duval, Saarstahl) — producers (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.