Nickel Alloy DZ22 DS-HT
Heat-treated state
DS-HT = + /
Choose when a ~1080 °C diffusion/ageing treatment (often merged with coating diffusion) is used to even out γ′ size for slightly better mid-temperature strength and stability, at 6 % elongation.
Values for the DS-HT condition
Other DZ22 tempers and conditions
DZ22 is listed in 3 conditions; see the grade overview at DZ22.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
DS-ACDefault directionally solidified, as-cast (no heat treatment) | Use as the standard delivery state for directionally solidified precision castings run as-cast or only coating-diffused, balancing longitudinal creep strength to 1000 °C against process cost. | 850 | 980 | 7 | 40 HRC | 1.4 % IACS |
DS-HTThis page + / | Choose when a ~1080 °C diffusion/ageing treatment (often merged with coating diffusion) is used to even out γ′ size for slightly better mid-temperature strength and stability, at 6 % elongation. | 880 | 1,010 | 6 | 42 HRC | 1.4 % IACS |
directionally solidified + HIP + heat treatment | Pick for blades needing the highest fatigue and creep life: hot isostatic pressing after directional solidification removes microporosity, raising elongation to 10 % and tightening HCF scatter. | 890 | 1,040 | 10 | 41 HRC | 1.4 % IACS |
What is DZ22 DS-HT?
DZ22 DS-HT is DZ22 heat treated to DS-HT — choose when a ~1080 °C diffusion/ageing treatment (often merged with coating diffusion) is used to even out γ′ size for slightly better mid-temperature strength and stability, at 6 % elongation. DZ22 DS-HT has a yield strength of 880 MPa (128 ksi) and a tensile strength of 1,010 MPa (146 ksi) — stronger than 93% of nickel alloy grades. Elongation at break is 6% and the elastic modulus is 130 GPa (18.9 Msi). DZ22 DS-HT has a density of 8.6 g/cm³ (0.311 lb/in³), heavier than 67% of nickel alloy grades. It melts at 1,290°C (2,354 °F). DS-AC is the default condition FabDigit quotes; DS-HT is available on request or by drawing note.
Advantages
- High strength — 880 MPa (128 ksi), better than 93% of nickel alloy grades
- High service temperature — 1,020°C (1,868 °F), better than 82% of nickel alloy grades
Limitations
- Low stiffness — 130 GPa (18.9 Msi), worse than 99% of nickel alloy grades
- Difficult to machine — 7/100, worse than 97% of nickel alloy grades
- Limited formability — 3/100, worse than 97% of nickel alloy grades
- High embodied carbon — 17 kg CO₂/kg, worse than 96% of nickel alloy grades
- Difficult to weld — 10/100, worse than 94% of nickel alloy grades
DZ22 DS-HT properties
Typical room-temperature values for DZ22 DS-HT; 22 are specific to this condition. Other listed values are DZ22 reference data and may not represent this condition. Bars are the position among nickel alloy grades.
Physical3
DZ22 DS-HT has a density of 8.6 g/cm³ (0.311 lb/in³), heavier than 67% of nickel alloy grades. It melts at 1,290°C (2,354 °F).
Mechanical15
DZ22 DS-HT has a yield strength of 880 MPa (128 ksi) and a tensile strength of 1,010 MPa (146 ksi) — stronger than 93% of nickel alloy grades. Elongation at break is 6% and the elastic modulus is 130 GPa (18.9 Msi).
Thermal5
DZ22 DS-HT is rated for continuous service to 1,020°C (1,868 °F). It conducts heat at 10.5 W/m·K (6.07 BTU/hr·ft·°F), worse than 73% of nickel alloy grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
DZ22 DS-HT conducts electricity at 1.4 % IACS, worse than 79% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is good (64/100), worse than 85% of nickel alloy grades.
Sustainability4
Producing a kilogram of DZ22 DS-HT takes about 250 MJ of energy and emits 17 kg of CO₂ — more than 97% of nickel alloy grades. Typical recycled content is 20%.
Manufacturability8
DZ22 DS-HT's machinability is not recommended (7/100, worse than 97% of nickel alloy grades); weldability not recommended (10/100); formability not recommended (3/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with DZ22 DS-HT
Is DZ22 easy to machine?
Conventional cutting is barely feasible; airfoil surfaces are produced by precision casting, while roots and cooling holes are finished by creep-feed grinding, ECM and EDM or laser drilling.
Can DZ22 be welded?
Weldability is poor, as high Al+Ti causes solidification and strain-age cracking. Repairs are usually made by vacuum brazing or by laser cladding with preheat followed by heat treatment.
Can DZ22 be formed, bent or molded?
Formed only by directional solidification (HRS or LMC) vacuum precision casting, with strict control of seed/grain selector, thermal gradient and withdrawal rate to avoid stray grains and freckles. No forging or cold forming.
What surface finishes work on DZ22?
After shot peening or abrasive flow machining and chemical cleaning, parts receive aluminide or MCrAlY coatings plus YSZ thermal-barrier layers. Anodizing does not apply.
DZ22 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 | 0.11 – 0.18 | 0.14 |
| Cr | 8 – 10 | 9 |
| Co | 9 – 11 | 10 |
| Wmain solid-solution strengthening element | 11.5 – 13 | 12 |
| Algamma-prime forming element | 4.7 – 5.5 | 5 |
| Ti | 1.7 – 2.3 | 2 |
| Nb | 0.8 – 1.3 | 1 |
| Hfimproves transverse ductility, limits casting hot cracking | 1.2 – 1.8 | 1.5 |
| Bgrain boundary strengthening | 0.01 – 0.02 | 0.02 |
| Zr | 0.03 – 0.08 | 0.05 |
| Feimpurity limit | ≤ 0.5 | — |
| Simpurity limit | ≤ 0.01 | — |
| Ni | balance | — |
DZ22 DS-HT — frequently asked
What is DZ22 DS-HT used for?
DZ22 DS-HT is typically used for directionally solidified turbine blades, aero-engine hot-section components and industrial gas turbine blades. In short: directionally solidified blade alloy; 1000 °C service capability; highest creep life here.
What is the yield strength of DZ22 DS-HT?
DZ22 DS-HT has a typical yield strength of 880 MPa (128 ksi) and a tensile strength of 1,010 MPa (146 ksi) — stronger than 93% of nickel alloy grades. Strength varies by condition: see the 3 listed tempers.
Is DZ22 DS-HT easy to machine?
Not especially — machinability is rated not recommended (7/100, worse than 97% of nickel alloy grades). Conventional cutting is barely feasible; airfoil surfaces are produced by precision casting, while roots and cooling holes are finished by creep-feed grinding, ECM and EDM or laser drilling.
Can DZ22 DS-HT be welded?
Not readily — weldability is rated not recommended (10/100). Weldability is poor, as high Al+Ti causes solidification and strain-age cracking. Repairs are usually made by vacuum brazing or by laser cladding with preheat followed by heat treatment.
What surface finishes work on DZ22 DS-HT?
After shot peening or abrasive flow machining and chemical cleaning, parts receive aluminide or MCrAlY coatings plus YSZ thermal-barrier layers. Anodizing does not apply.
Can DZ22 DS-HT be formed, bent or molded?
Formed only by directional solidification (HRS or LMC) vacuum precision casting, with strict control of seed/grain selector, thermal gradient and withdrawal rate to avoid stray grains and freckles. No forging or cold forming.
What is the maximum service temperature of DZ22 DS-HT?
DZ22 DS-HT is rated for continuous use to about 1,020°C (1,868 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between DZ22 DS-AC and DZ22 DS-HT?
DS-AC is the default condition — use as the standard delivery state for directionally solidified precision castings run as-cast or only coating-diffused, balancing longitudinal creep strength to 1000 °C against process cost. DS-HT: choose when a ~1080 °C diffusion/ageing treatment (often merged with coating diffusion) is used to even out γ′ size for slightly better mid-temperature strength and stability, at 6 % elongation. Yield strength is 850 MPa in DS-AC versus 880 MPa in DS-HT.
Sources
- Superalloys II / ASM Specialty Handbook: Heat-Resistant Materials (MAR-M200+Hf ) — ASM International (1997)
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.