Steel Cronidur 30 H+DF+T250
Heat-treated state
UNS S42086 · EN X30CrMoN15-1
H+DF+T250 = hardened, deep-frozen and tempered 250 °C
Slightly softer, more dimensionally stable condition for bearings running near 200 °C.
Values for the H+DF+T250 condition
Other Cronidur 30 tempers and conditions
Cronidur 30 is listed in 4 conditions; see the grade overview at Cronidur 30.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Delivery condition for machining of rings and shafts before hardening. | 600 | 900 | 14 | 26 HRC | — |
Hardened, deep-frozen and high-temperature tempered ~480–525 °C | Secondary-hardening temper for elevated-temperature dimensional stability (service to ~400 °C) at slightly reduced hardness and corrosion resistance. | 1,700 | 1,950 | 6 | 57 HRC | 2.4 % IACS |
H+DF+T250This page Hardened, deep-frozen and tempered 250 °C | Slightly softer, more dimensionally stable condition for bearings running near 200 °C. | 1,780 | 2,000 | 5 | 58 HRC | 2.3 % IACS |
H+DF+T180Default Hardened, deep-frozen and tempered 180 °C | Standard bearing condition: max hardness and rolling contact fatigue life for service up to ~250 °C. | 1,850 | 2,100 | 4 | 59 HRC | — |
What is Cronidur 30 H+DF+T250?
Cronidur 30 H+DF+T250 is Cronidur 30 heat treated to H+DF+T250 — slightly softer, more dimensionally stable condition for bearings running near 200 °C. Cronidur 30 H+DF+T250 has a yield strength of 1,780 MPa (258 ksi) and a tensile strength of 2,000 MPa (290 ksi) — stronger than 99% of steel grades. Elongation at break is 5% and the elastic modulus is 200 GPa (29 Msi). Cronidur 30 H+DF+T250 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 95% of steel grades. It melts at 1,400°C (2,552 °F). H+DF+T180 is the default condition FabDigit quotes; H+DF+T250 is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 90/100, better than 100% of steel grades
- High strength — 1,780 MPa (258 ksi), better than 99% of steel grades
- Good corrosion resistance — 57/100, better than 99% of steel grades
Limitations
- Low fracture toughness — 21 MPa·√m (19.1 ksi·√in), worse than 99% of steel grades
- Difficult to machine — 12/100, worse than 99% of steel grades
- Limited formability — 5/100, worse than 99% of steel grades
- Limited ductility — 5%, worse than 98% of steel grades
- Poor heat conductor — 16 W/m·K (9.24 BTU/hr·ft·°F), worse than 98% of steel grades
Cronidur 30 H+DF+T250 properties
Typical room-temperature values for Cronidur 30 H+DF+T250; 22 are specific to this condition. Other listed values are Cronidur 30 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
Cronidur 30 H+DF+T250 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 95% of steel grades. It melts at 1,400°C (2,552 °F).
Mechanical15
Cronidur 30 H+DF+T250 has a yield strength of 1,780 MPa (258 ksi) and a tensile strength of 2,000 MPa (290 ksi) — stronger than 99% of steel grades. Elongation at break is 5% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
Cronidur 30 H+DF+T250 is rated for continuous service to 300°C (572 °F). It conducts heat at 16 W/m·K (9.24 BTU/hr·ft·°F), worse than 98% of steel grades. Thermal expansion is 10.5 µm/m·K (5.83 µin/in·°F).
Electrical3
Cronidur 30 H+DF+T250 conducts electricity at 2.3 % IACS, worse than 98% of steel grades.
Chemical & Environmental3
Corrosion resistance is good (57/100), better than 99% of steel grades.
Sustainability4
Producing a kilogram of Cronidur 30 H+DF+T250 takes about 85 MJ of energy and emits 5.5 kg of CO₂ — more than 98% of steel grades. Typical recycled content is 25%.
Manufacturability7
Cronidur 30 H+DF+T250's machinability is not recommended (12/100, worse than 99% of steel grades); weldability poor (15/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Cronidur 30 H+DF+T250
Is Cronidur 30 easy to machine?
Machine rings and shafts in the annealed state with rigid setups and coated carbide at low speed; after hardening only grinding, honing and CBN hard turning are practical.
Can Cronidur 30 be welded?
Not recommended — high C+N martensite is highly crack sensitive; if unavoidable use electron-beam/laser with preheat and immediate re-heat-treatment.
Can Cronidur 30 be formed, bent or molded?
Hot forge 1100–850 °C with slow controlled cooling and immediate soft anneal; no cold forming in hardened condition.
What surface finishes work on Cronidur 30?
Passivate per ASTM A967 after grinding; superfinish/lap raceways for maximum RCF life; PVD (TiN/DLC) or black oxide can be applied below the tempering temperature.
Cronidur 30 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 | 0.25 – 0.35 | 0.31 |
| Ndissolved by pressurized ESR (PESR) | 0.3 – 0.5 | 0.38 |
| Cr | 14 – 16 | 15.2 |
| Mo | 0.85 – 1.1 | 1 |
| Si | ≤ 1 | 0.4 |
| Mn | ≤ 1 | 0.4 |
| P | ≤ 0.03 | — |
| S | ≤ 0.02 | — |
| Fe | balance | — |
Cronidur 30 H+DF+T250 — frequently asked
What is Cronidur 30 H+DF+T250 used for?
Cronidur 30 H+DF+T250 is typically used for aerospace bearings, marine bearings and high-performance corrosion-resistant bearings. In short: best corrosion resistance among bearing steels; higher RCF life than 440C; low elongation, 250 °C limit.
What is the yield strength of Cronidur 30 H+DF+T250?
Cronidur 30 H+DF+T250 has a typical yield strength of 1,780 MPa (258 ksi) and a tensile strength of 2,000 MPa (290 ksi) — stronger than 99% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is Cronidur 30 H+DF+T250 easy to machine?
Not especially — machinability is rated not recommended (12/100, worse than 99% of steel grades). Machine rings and shafts in the annealed state with rigid setups and coated carbide at low speed; after hardening only grinding, honing and CBN hard turning are practical.
Can Cronidur 30 H+DF+T250 be welded?
Not readily — weldability is rated poor (15/100). Not recommended — high C+N martensite is highly crack sensitive; if unavoidable use electron-beam/laser with preheat and immediate re-heat-treatment.
What surface finishes work on Cronidur 30 H+DF+T250?
Passivate per ASTM A967 after grinding; superfinish/lap raceways for maximum RCF life; PVD (TiN/DLC) or black oxide can be applied below the tempering temperature.
Can Cronidur 30 H+DF+T250 be formed, bent or molded?
Hot forge 1100–850 °C with slow controlled cooling and immediate soft anneal; no cold forming in hardened condition.
What is the maximum service temperature of Cronidur 30 H+DF+T250?
Cronidur 30 H+DF+T250 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Cronidur 30 H+DF+T180 and Cronidur 30-ANN?
H+DF+T180 is the default condition — standard bearing condition: max hardness and rolling contact fatigue life for service up to ~250 °C. ANN: delivery condition for machining of rings and shafts before hardening. Yield strength is 1,850 MPa in H+DF+T180 versus 600 MPa in ANN.
Sources
- Cronidur 30 (X30CrMoN15-1) high-nitrogen stainless steel data sheet — Energietechnik Essen GmbH (2020)
- DIN EN 10088 / Werkstoff X30CrMoN15-1 (1.4108) — DIN/CEN (2014)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Bearing steel rolling contact fatigue and corrosion comparison studies (440C vs high-nitrogen steels) — tribology/bearing literature (2015)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.