Titanium IMI 829 AB-STA
Heat-treated state
AB-STA = α+β STA
Finer, more equiaxed structure for parts needing better low-cycle fatigue and room-temperature ductility at some loss of creep strength.
Values for the AB-STA condition
Other IMI 829 tempers and conditions
IMI 829 is listed in 3 conditions; see the grade overview at IMI 829.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Supply condition for forging stock and semi-finished bar before final beta solution treatment and ageing. | 820 | 930 | 13 | 31 HRC | 1.1 % IACS |
BETA-STADefault beta solution treated (≈1050 °C, air/oil cool) and aged ≈625 °C | Standard rotating-grade condition for discs, blades and rings; best creep and oxidation performance to ~580 °C. | 865 | 980 | 11 | 33 HRC | 1.1 % IACS |
AB-STAThis page Α+β STA | Finer, more equiaxed structure for parts needing better low-cycle fatigue and room-temperature ductility at some loss of creep strength. | 890 | 1,000 | 13 | 34 HRC | 1.1 % IACS |
What is IMI 829 AB-STA?
IMI 829 AB-STA is IMI 829 heat treated to AB-STA — finer, more equiaxed structure for parts needing better low-cycle fatigue and room-temperature ductility at some loss of creep strength. IMI 829 AB-STA has a yield strength of 890 MPa (129 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 80% of titanium grades. Elongation at break is 13% and the elastic modulus is 122 GPa (17.7 Msi). IMI 829 AB-STA has a density of 4.54 g/cm³ (0.164 lb/in³), heavier than 80% of titanium grades. It melts at 1,550°C (2,822 °F). BETA-STA is the default condition FabDigit quotes; AB-STA is available on request or by drawing note.
Advantages
- Stiff — 122 GPa (17.7 Msi), better than 100% of titanium grades
- High service temperature — 520°C (968 °F), better than 97% of titanium grades
- High strength — 890 MPa (129 ksi), better than 80% of titanium grades
Limitations
- Difficult to weld — 45/100, worse than 92% of titanium grades
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 90% of titanium grades
- Limited formability — 22/100, worse than 78% of titanium grades
IMI 829 AB-STA properties
Typical room-temperature values for IMI 829 AB-STA; 22 are specific to this condition. Other listed values are IMI 829 reference data and may not represent this condition. Bars are the position among titanium grades.
Physical3
IMI 829 AB-STA has a density of 4.54 g/cm³ (0.164 lb/in³), heavier than 80% of titanium grades. It melts at 1,550°C (2,822 °F).
Mechanical16
IMI 829 AB-STA has a yield strength of 890 MPa (129 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 80% of titanium grades. Elongation at break is 13% and the elastic modulus is 122 GPa (17.7 Msi).
Thermal6
IMI 829 AB-STA is rated for continuous service to 520°C (968 °F). It conducts heat at 7.2 W/m·K (4.16 BTU/hr·ft·°F), worse than 67% of titanium grades. Thermal expansion is 9.5 µm/m·K (5.28 µin/in·°F).
Electrical3
IMI 829 AB-STA conducts electricity at 1.1 % IACS, worse than 67% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), worse than 93% of titanium grades.
Sustainability4
Producing a kilogram of IMI 829 AB-STA takes about 700 MJ of energy and emits 43 kg of CO₂ — more than 74% of titanium grades. Typical recycled content is 15%.
Manufacturability8
IMI 829 AB-STA's machinability is poor (15/100, worse than 97% of titanium grades); weldability fair (45/100); formability poor (22/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with IMI 829 AB-STA
Is IMI 829 easy to machine?
Machine like a high-strength near-alpha Ti: rigid setup, sharp uncoated-carbide or coated carbide, 20–35 m/min turning, heavy flood coolant, positive rake and no dwell to avoid work hardening and fire risk from fine chips.
Can IMI 829 be welded?
GTAW/EBW in high-purity argon or vacuum with full trailing-gas or chamber protection; post-weld stress relief/age at ~600–625 °C is required and weld ductility remains lower than base metal — avoid welds in rotating parts.
Can IMI 829 be formed, bent or molded?
Hot work only: forge/ring-roll in the 950–1050 °C range with controlled final beta reduction; cold forming is impractical, sheet work needs hot sizing or creep forming.
What surface finishes work on IMI 829?
Grit blast plus pickling to remove alpha case after hot working; shot peening for fatigue, and anodic/chemical oxide or Ti-N type coatings where galling protection is needed.
IMI 829 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 |
|---|---|---|
| Alalpha stabiliser | 5 – 6.1 | 5.5 |
| Sn | 3 – 4 | 3.5 |
| Zr | 2.5 – 3.5 | 3 |
| Nbimproves oxidation resistance | 0.7 – 1.3 | 1 |
| Mo | 0.2 – 0.4 | 0.3 |
| Sisilicide precipitation for creep resistance | 0.2 – 0.4 | 0.3 |
| C | ≤ 0.08 | — |
| Fe | ≤ 0.2 | — |
| Omax, kept low for creep/toughness | ≤ 0.15 | 0.1 |
| N | ≤ 0.05 | — |
| H | ≤ 0.01 | — |
| Ti | balance | — |
IMI 829 AB-STA — frequently asked
What is IMI 829 AB-STA used for?
IMI 829 AB-STA is typically used for turbine engine discs, compressor blades, HP compressor disc and drum forgings, engine rings and spacers, static hot-section brackets and blade and vane roots. In short: 580 °C creep capability; higher-temperature IMI 685 successor; hot-section rotating disc alloy.
What is the yield strength of IMI 829 AB-STA?
IMI 829 AB-STA has a typical yield strength of 890 MPa (129 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 80% of titanium grades. Strength varies by condition: see the 3 listed tempers.
Is IMI 829 AB-STA easy to machine?
Not especially — machinability is rated poor (15/100, worse than 97% of titanium grades). Machine like a high-strength near-alpha Ti: rigid setup, sharp uncoated-carbide or coated carbide, 20–35 m/min turning, heavy flood coolant, positive rake and no dwell to avoid work hardening and fire risk from fine chips.
Can IMI 829 AB-STA be welded?
With care — weldability is rated fair (45/100). GTAW/EBW in high-purity argon or vacuum with full trailing-gas or chamber protection; post-weld stress relief/age at ~600–625 °C is required and weld ductility remains lower than base metal — avoid welds in rotating parts.
What surface finishes work on IMI 829 AB-STA?
Grit blast plus pickling to remove alpha case after hot working; shot peening for fatigue, and anodic/chemical oxide or Ti-N type coatings where galling protection is needed.
Can IMI 829 AB-STA be formed, bent or molded?
Hot work only: forge/ring-roll in the 950–1050 °C range with controlled final beta reduction; cold forming is impractical, sheet work needs hot sizing or creep forming.
What is the maximum service temperature of IMI 829 AB-STA?
IMI 829 AB-STA is rated for continuous use to about 520°C (968 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between IMI 829 BETA-STA and IMI 829-ANN?
BETA-STA is the default condition — standard rotating-grade condition for discs, blades and rings; best creep and oxidation performance to ~580 °C. ANN: supply condition for forging stock and semi-finished bar before final beta solution treatment and ageing. Yield strength is 865 MPa in BETA-STA versus 820 MPa in ANN.
Sources
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (titanium alloys) — ASM International (1990)
- Materials Properties Handbook: Titanium Alloys — ASM International (1994)
- IMI Titanium high-temperature alloy data (IMI 685 / IMI 829 / IMI 834 family) — IMI Titanium / TIMET UK (1990)
- Titanium and Titanium Alloys — Fundamentals and Applications (Leyens & Peters) — Wiley-VCH (2003)
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.