Cobalt-Chrome Alloy Haynes 188
UNS R30188 · EN 2.4683
Haynes 188 is a cobalt-base solid-solution high-temperature alloy (Co-22Ni-22Cr-14W; UNS R30188, 2.4683) with better oxidation resistance than L605, used for hot-section sheet and plate hardware.
Reference datasheet — Haynes 188 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 SA condition
Haynes 188 tempers and conditions
Haynes 188 is supplied in 3 conditions, soft to hard. SA is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SADefault Solution annealed | Standard mill condition for combustor and hot-gas sheet metal; best ductility and formability. | 464 | 960 | 53 | 215 HB | 1.7 % IACS |
As-welded deposit | Reference condition for weld-joint design in fabricated combustor/duct assemblies without post-weld anneal. | 490 | 840 | 32 | 225 HB | — |
Cold worked | Pick for high-temperature springs, seals and fine wire where strength matters more than ductility. | 1,250 | 1,450 | 4 | 42 HRC | — |
Supply forms, finishes and certifications
Ways Haynes 188 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
SA-BAR | SA | Supply form |
SA-Plate | SA | Supply form |
What is Haynes 188?
Haynes 188 is a cobalt-base solid-solution high-temperature alloy (Co-22Ni-22Cr-14W; UNS R30188, 2.4683) with better oxidation resistance than L605, used for hot-section sheet and plate hardware. Solution-annealed material gives 464 MPa yield, 960 MPa tensile, 53% elongation and about 215 HB (95 HRB), with service to 1095 °C and good arc weldability (score 75). It work-hardens rapidly and machines with difficulty, and cold-forming loads are roughly double those for stainless; L605 is the nearest alternative where slightly lower oxidation resistance is acceptable. Haynes 188 has a density of 8.98 g/cm³ (0.324 lb/in³), heavier than 91% of cobalt-chrome alloy grades. It melts at 1,302°C (2,376 °F). Haynes 188 has a yield strength of 464 MPa (67.3 ksi) and a tensile strength of 960 MPa (139 ksi) — weaker than 85% of cobalt-chrome alloy grades. Elongation at break is 53% and the elastic modulus is 232 GPa (33.6 Msi).
What is Haynes 188 used for?
- combustor liners
- afterburner components
- gas turbine hot sections
- high-temp springs
- furnace hardware
Advantages
- High service temperature — 1,095°C (2,003 °F), better than 100% of cobalt-chrome alloy grades
- Forms and bends easily — 65/100, better than 100% of cobalt-chrome alloy grades
- Readily welded — 75/100, better than 98% of cobalt-chrome alloy grades
- Ductile — tolerates forming and impact — 53%, better than 93% of cobalt-chrome alloy grades
Limitations
- High embodied carbon — 19 kg CO₂/kg, worse than 98% of cobalt-chrome alloy grades
- Poor heat conductor — 10.8 W/m·K (6.24 BTU/hr·ft·°F), worse than 93% of cobalt-chrome alloy grades
- Hard to polish — 70/100, worse than 91% of cobalt-chrome alloy grades
- Low strength — 464 MPa (67.3 ksi), worse than 85% of cobalt-chrome alloy grades
Haynes 188 properties
Typical room-temperature values for Haynes 188-SA; bars are the position among cobalt-chrome alloy grades.
Physical3
Haynes 188 has a density of 8.98 g/cm³ (0.324 lb/in³), heavier than 91% of cobalt-chrome alloy grades. It melts at 1,302°C (2,376 °F).
Mechanical14
Haynes 188 has a yield strength of 464 MPa (67.3 ksi) and a tensile strength of 960 MPa (139 ksi) — weaker than 85% of cobalt-chrome alloy grades. Elongation at break is 53% and the elastic modulus is 232 GPa (33.6 Msi).
Thermal5
Haynes 188 is rated for continuous service to 1,095°C (2,003 °F). It conducts heat at 10.8 W/m·K (6.24 BTU/hr·ft·°F), worse than 93% of cobalt-chrome alloy grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
Haynes 188 conducts electricity at 1.7 % IACS, worse than 92% of cobalt-chrome alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (78/100), better than 54% of cobalt-chrome alloy grades.
Sustainability4
Producing a kilogram of Haynes 188 takes about 280 MJ of energy and emits 19 kg of CO₂ — more than 100% of cobalt-chrome alloy grades. Typical recycled content is 30%.
Manufacturability8
Haynes 188's machinability is poor (15/100, better than 79% of cobalt-chrome alloy grades); weldability very good (75/100); formability good (65/100).
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 cobalt-chrome alloy family
Yield strength against density for every cobalt-chrome alloy grade FabDigit runs. Haynes 188 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Haynes 188
Is Haynes 188 easy to machine?
Very difficult: work-hardening Co-W solid solution needs rigid setups, positive-rake carbide or ceramic tools, low speed/heavy positive feed and flood coolant to avoid glazing.
Can Haynes 188 be welded?
Readily joined by GTAW/GMAW/resistance and EB welding with matching 188 filler; keep heat input low, no preheat needed, solution anneal after heavy welding to restore ductility.
Can Haynes 188 be formed, bent or molded?
Good cold formability in the solution-annealed condition but forces are roughly double those for stainless; interstage anneal at ~1175 °C with rapid quench, hot work 1175–980 °C.
Haynes 188 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 |
|---|---|---|
| Ni | 20 – 24 | 22 |
| Cr | 20 – 24 | 22 |
| W | 13 – 16 | 14 |
| Fe | ≤ 3 | 1.5 |
| Mn | ≤ 1.25 | 0.6 |
| Si | 0.2 – 0.5 | 0.35 |
| C | 0.05 – 0.15 | 0.1 |
| Larare-earth addition for oxide-scale adherence | 0.02 – 0.12 | 0.03 |
| B | ≤ 0.02 | |
| P | ≤ 0.02 | |
| S | ≤ 0.02 | |
| Cobalance, nominally ~39 % | balance |
What surface finishes work on Haynes 188?
Not anodizable — pickle/grit-blast to remove oxide, then optionally aluminide diffusion or thermal-barrier coat for combustor service; polishes well to a bright hard surface.
Equivalent designations
Standards and trade names that resolve to Cobalt-Chrome Alloy Haynes 188 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- R30188
- EN / DIN / Werkstoff-Nr.
- 2.4683
How much does Haynes 188 cost?
Haynes 188 is a high-cost cobalt-chrome alloy ($$$$), 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.
Haynes 188 — frequently asked
What is Haynes 188 used for?
Haynes 188 is typically used for combustor liners, afterburner components, gas turbine hot sections, high-temp springs and furnace hardware. In short: best-oxidizing Co-Cr-W sheet alloy; 1095 °C service, weldable; tougher to machine than L605.
What is the yield strength of Haynes 188?
Haynes 188 has a typical yield strength of 464 MPa (67.3 ksi) and a tensile strength of 960 MPa (139 ksi) — weaker than 85% of cobalt-chrome alloy grades. Strength varies by condition: see the 3 listed tempers.
Is Haynes 188 easy to machine?
Not especially — machinability is rated poor (15/100, better than 79% of cobalt-chrome alloy grades). Very difficult: work-hardening Co-W solid solution needs rigid setups, positive-rake carbide or ceramic tools, low speed/heavy positive feed and flood coolant to avoid glazing.
Can Haynes 188 be welded?
Yes — weldability is rated very good (75/100). Readily joined by GTAW/GMAW/resistance and EB welding with matching 188 filler; keep heat input low, no preheat needed, solution anneal after heavy welding to restore ductility.
What surface finishes work on Haynes 188?
Not anodizable — pickle/grit-blast to remove oxide, then optionally aluminide diffusion or thermal-barrier coat for combustor service; polishes well to a bright hard surface.
Can Haynes 188 be formed, bent or molded?
Good cold formability in the solution-annealed condition but forces are roughly double those for stainless; interstage anneal at ~1175 °C with rapid quench, hot work 1175–980 °C.
What is the maximum service temperature of Haynes 188?
Haynes 188 is rated for continuous use to about 1,095°C (2,003 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Haynes 188-SA and Haynes 188-CW?
SA is the default condition — standard mill condition for combustor and hot-gas sheet metal; best ductility and formability. CW: pick for high-temperature springs, seals and fine wire where strength matters more than ductility. Yield strength is 464 MPa in SA versus 1,250 MPa in CW.
How much does Haynes 188 cost?
Haynes 188 is a high-cost cobalt-chrome alloy ($$$$), 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
- HAYNES 188 alloy brochure H-3001 — Haynes International (2020)
- ASTM B435 — UNS R30188 Sheet, Plate and Strip — ASTM (2017)
- ASTM B572 — UNS R30188 Rod — ASTM (2017)
- AMS 5608 / AMS 5772 / AMS 5801 — SAE International (2018)
- ASM Handbook Vol.2 — Properties of Cobalt-Base Superalloys — ASM International (1990)
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.