Cobalt-Chrome Alloy Tribaloy T-400-AC (Spheroidize annealed)
Heat-treated state · default condition
UNS R30400
Pick for solid cast wear parts, seal rings and valve trim where the whole part must be wear resistant.
Values for the AC condition
Other Tribaloy T-400 tempers and conditions
Tribaloy T-400 is listed in 2 conditions; see the grade overview at Tribaloy T-400.
- AC
- HIP
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ACDefaultThis page Spheroidize annealed | Pick for solid cast wear parts, seal rings and valve trim where the whole part must be wear resistant. | 620 | 690 | 0.5 | 56 HRC | 1.8 % IACS |
Hot isostatic pressed | Pick for large near-net solid components needing a finer, more uniform Laves distribution and slightly better toughness than as-cast. | 700 | 800 | 1 | 55 HRC | 1.8 % IACS |
What is Tribaloy T-400-AC?
Tribaloy T-400-AC is Tribaloy T-400 heat treated to AC — pick for solid cast wear parts, seal rings and valve trim where the whole part must be wear resistant. Tribaloy T-400-AC has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 67% of cobalt-chrome alloy grades. Elongation at break is 0.5% and the elastic modulus is 225 GPa (32.6 Msi). Tribaloy T-400-AC has a density of 8.61 g/cm³ (0.311 lb/in³), heavier than 71% of cobalt-chrome alloy grades. It melts at 1,245°C (2,273 °F).
Limitations
- Limited ductility — 0.5%, worse than 89% of cobalt-chrome alloy grades
- High embodied carbon — 16 kg CO₂/kg, worse than 84% of cobalt-chrome alloy grades
- Low fracture toughness — 14 MPa·√m (12.7 ksi·√in), worse than 82% of cobalt-chrome alloy grades
- Needs corrosion protection — 68/100, worse than 80% of cobalt-chrome alloy grades
Tribaloy T-400-AC properties
Typical room-temperature values for Tribaloy T-400-AC; 22 are specific to this condition. Other listed values are Tribaloy T-400 reference data and may not represent this condition. Bars are the position among cobalt-chrome alloy grades.
Physical3
Tribaloy T-400-AC has a density of 8.61 g/cm³ (0.311 lb/in³), heavier than 71% of cobalt-chrome alloy grades. It melts at 1,245°C (2,273 °F).
Mechanical16
Tribaloy T-400-AC has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 67% of cobalt-chrome alloy grades. Elongation at break is 0.5% and the elastic modulus is 225 GPa (32.6 Msi).
Thermal5
Tribaloy T-400-AC is rated for continuous service to 760°C (1,400 °F). It conducts heat at 14 W/m·K (8.09 BTU/hr·ft·°F), worse than 55% of cobalt-chrome alloy grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
Tribaloy T-400-AC conducts electricity at 1.8 % IACS, worse than 75% of cobalt-chrome alloy grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), worse than 80% of cobalt-chrome alloy grades.
Sustainability4
Producing a kilogram of Tribaloy T-400-AC takes about 190 MJ of energy and emits 16 kg of CO₂ — more than 70% of cobalt-chrome alloy grades. Typical recycled content is 20%.
Manufacturability8
Tribaloy T-400-AC's machinability is not recommended (5/100, worse than 82% of cobalt-chrome alloy grades); weldability fair (35/100); formability not recommended (2/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Tribaloy T-400-AC
Is Tribaloy T-400 easy to machine?
Effectively non-machinable by turning/milling — finish by CBN/SiC/diamond grinding, lapping or EDM; keep grinding wheels sharp and coolant heavy to avoid surface cracking.
Can Tribaloy T-400 be welded?
Deposit by PTA, GTAW, oxy-acetylene or laser with 250–500 °C preheat, minimal interpass cooling and slow, controlled post-weld cooling; expect check cracks in thick single passes and limit dilution to keep hardness.
Can Tribaloy T-400 be formed, bent or molded?
No cold or hot forming — the Laves-phase structure is brittle; produce shapes by casting, HIP or overlay/near-net cladding.
What surface finishes work on Tribaloy T-400?
Lap or diamond-polish sealing faces to Ra <0.1 µm; no anodizing, and plating is unnecessary since the alloy is its own corrosion/wear surface.
Tribaloy T-400 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 |
|---|---|---|
| Moforms CoMoSi Laves phase | 26 – 30 | 28.5 |
| Cr | 7.5 – 9.5 | 8.5 |
| SiLaves-phase stabiliser | 2 – 3 | 2.6 |
| Clow carbon — hardness from intermetallic, not carbides | ≤ 0.08 | 0.05 |
| Fe | ≤ 3 | 1 |
| Ni | ≤ 3 | 1 |
| Mn | ≤ 1 | 0.3 |
| Cobalance, nominally ~58 % | balance | — |
Tribaloy T-400-AC — frequently asked
What is Tribaloy T-400-AC used for?
Tribaloy T-400-AC is typically used for pump wear rings, valve seats and seals, bushings and thermal spray coatings. In short: top galling-resistance hardfacing; laves-phase, near non-machinable; 760 °C wear surface.
What is the yield strength of Tribaloy T-400-AC?
Tribaloy T-400-AC has a typical yield strength of 620 MPa (89.9 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 67% of cobalt-chrome alloy grades. Strength varies by condition: see the 2 listed tempers.
Is Tribaloy T-400-AC easy to machine?
Not especially — machinability is rated not recommended (5/100, worse than 82% of cobalt-chrome alloy grades). Effectively non-machinable by turning/milling — finish by CBN/SiC/diamond grinding, lapping or EDM; keep grinding wheels sharp and coolant heavy to avoid surface cracking.
Can Tribaloy T-400-AC be welded?
With care — weldability is rated fair (35/100). Deposit by PTA, GTAW, oxy-acetylene or laser with 250–500 °C preheat, minimal interpass cooling and slow, controlled post-weld cooling; expect check cracks in thick single passes and limit dilution to keep hardness.
What surface finishes work on Tribaloy T-400-AC?
Lap or diamond-polish sealing faces to Ra <0.1 µm; no anodizing, and plating is unnecessary since the alloy is its own corrosion/wear surface.
Can Tribaloy T-400-AC be formed, bent or molded?
No cold or hot forming — the Laves-phase structure is brittle; produce shapes by casting, HIP or overlay/near-net cladding.
What is the maximum service temperature of Tribaloy T-400-AC?
Tribaloy T-400-AC is rated for continuous use to about 760°C (1,400 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Tribaloy T-400-AC and Tribaloy T-400-HIP?
AC is the default condition — pick for solid cast wear parts, seal rings and valve trim where the whole part must be wear resistant. HIP: pick for large near-net solid components needing a finer, more uniform Laves distribution and slightly better toughness than as-cast. Yield strength is 620 MPa in AC versus 700 MPa in HIP.
Sources
- Tribaloy T-400 alloy datasheet — Kennametal Stellite (2021)
- Tribaloy alloy family — Deloro / Oerlikon Metco hardfacing powders — Oerlikon Metco (2022)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (Cobalt alloys) — ASM International (1990)
- AWS A5.13 / A5.21 — Surfacing Electrodes and Rods (CoCr/Co-Mo classifications) — AWS (2010)
- UNS R30400 alloy designation data — SAE/ASTM Unified Numbering System (2017)
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.