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Cobalt-Chrome Alloy ERCoCr-C-AW (As-welded deposit)

Heat-treated state · default condition

UNS R30012

Default reference condition: 2+ layer deposit where substrate dilution no longer affects chemistry — full as-deposited hardness and wear resistance.

High cost $$$$

Values for the AW condition

Other ERCoCr-C tempers and conditions

ERCoCr-C is listed in 2 conditions; see the grade overview at ERCoCr-C.

Compare all 2 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
AWDefaultThis page
As-welded deposit
Default reference condition: 2+ layer deposit where substrate dilution no longer affects chemistry — full as-deposited hardness and wear resistance.6006200.552 HRC1.8 % IACS
Stress relieved
Post-weld stress relief to reduce check-cracking and residual stress in thick or multipass deposits; hardness essentially retained.6106500.851 HRC1.8 % IACS

What is ERCoCr-C-AW?

ERCoCr-C-AW is ERCoCr-C heat treated to AW — default reference condition: 2+ layer deposit where substrate dilution no longer affects chemistry — full as-deposited hardness and wear resistance. ERCoCr-C-AW has a yield strength of 600 MPa (87 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 52% of cobalt-chrome alloy grades. Elongation at break is 0.5% and the elastic modulus is 250 GPa (36.3 Msi). ERCoCr-C-AW has a density of 8.68 g/cm³ (0.314 lb/in³), heavier than 79% of cobalt-chrome alloy grades. It melts at 1,265°C (2,309 °F).

Limitations

  • Limited ductility — 0.5%, worse than 89% of cobalt-chrome alloy grades

ERCoCr-C-AW properties

Typical room-temperature values for ERCoCr-C-AW; 22 are specific to this condition. Other listed values are ERCoCr-C reference data and may not represent this condition. Bars are the position among cobalt-chrome alloy grades.

Physical3

ERCoCr-C-AW has a density of 8.68 g/cm³ (0.314 lb/in³), heavier than 79% of cobalt-chrome alloy grades. It melts at 1,265°C (2,309 °F).

Density8.68 g/cm³0.31 lb/in³
Melting Point (Solidus)1,265°C2,309 °F
Liquidus Temperature1,300°C2,372 °F

Mechanical16

ERCoCr-C-AW has a yield strength of 600 MPa (87 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 52% of cobalt-chrome alloy grades. Elongation at break is 0.5% and the elastic modulus is 250 GPa (36.3 Msi).

Elastic (Young's) Modulus250 GPa36.3 Msi
Shear Modulus96 GPa13.9 Msi
Bulk Modulus208 GPa30.2 Msi
Poisson's Ratio0.3
Tensile Strength (Ultimate)620 MPa89.9 ksi
Yield Strength (0.2% offset)600 MPa87 ksi
Elongation at Break0.5%
Reduction in Area0.5%
Compressive Strength2,000 MPa290 ksi
Shear Strength420 MPa60.9 ksi
Fatigue Strength (Endurance Limit)250 MPa36.3 ksi
Fracture Toughness (K_IC)22 MPa·√m20 ksi·√in
Charpy V-Notch Impact (RT)3 J2.2 ft·lbf
Hardness, Brinell520 HB
Hardness, Rockwell C52 HRC
Hardness, Vickers560 HV

Thermal5

ERCoCr-C-AW is rated for continuous service to 780°C (1,436 °F). It conducts heat at 14.8 W/m·K (8.55 BTU/hr·ft·°F), better than 84% of cobalt-chrome alloy grades. Thermal expansion is 11 µm/m·K (6.11 µin/in·°F).

Thermal Conductivity14.8 W/m·K8.6 BTU/hr·ft·°F
Specific Heat Capacity423 J/kg·K0.1 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)11 µm/m·K6.1 µin/in·°F
Max Service Temperature (continuous)780°C1,436 °F
Min Service Temperature-196°C-321 °F

Electrical3

ERCoCr-C-AW conducts electricity at 1.8 % IACS, worse than 75% of cobalt-chrome alloy grades.

Electrical Conductivity1.8 % IACS
Electrical Resistivity9.5×10⁻⁷ Ω·m37.4 µΩ·in
Magnetic Responseweakly magnetic

Chemical & Environmental2

Corrosion resistance is very good (70/100), worse than 71% of cobalt-chrome alloy grades.

Corrosion ResistanceVery good70/100
Chemical Resistance SummaryGood resistance to oxidizing acids, seawater and hot oxidation/sulfidation; attacked by hot reducing halide acids (HCl) and strongly reducing media; carbide network can be selectively corroded in aggressive acids.

Sustainability3

Producing a kilogram of ERCoCr-C-AW takes about 145 MJ of energy and emits 12 kg of CO₂ — less than 73% of cobalt-chrome alloy grades. Typical recycled content is 20%.

Embodied Energy (primary production)145 MJ/kg62,339 BTU/lb
Embodied Carbon (primary production)12 kg CO₂/kg
Typical Recycled Content20%

Manufacturability8

ERCoCr-C-AW's machinability is not recommended (5/100, worse than 82% of cobalt-chrome alloy grades); weldability fair (35/100); formability not recommended (2/100).

MachinabilityNot recommended5/100
Machinability Rating (AISI 1212 = 100 %)3%
WeldabilityFair35/100
Formability (cold)Not recommended2/100
CastabilityGood55/100
Brazeability / SolderabilityFair40/100
PolishabilityVery good75/100
Anodizing Responsen/a — cobalt alloy, not anodizable

Common Calculations5

Specific Strength (UTS / density)calculated71 kN·m/kg
Specific Stiffness (E / density)calculated28.8 MN·m/kg
Modulus of Resiliencecalculated720 kJ/m³
Thermal Diffusivitycalculated4 mm²/s
Thermal Shock Resistance Indexcalculated3

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with ERCoCr-C-AW

Is ERCoCr-C easy to machine?

Effectively unmachinable with carbide — finish by grinding (CBN/SiC wheels), EDM or lapping; leave 0.5–1 mm grind stock on the deposit.

Can ERCoCr-C be welded?

Deposit by OFW, GTAW, PTA, laser or FCAW with 200–450 °C preheat, controlled interpass temperature and slow cooling; limit passes and expect benign transverse check cracks in wide deposits.

Can ERCoCr-C be formed, bent or molded?

No cold forming possible; shape is set by deposition geometry or investment casting of the same chemistry.

What surface finishes work on ERCoCr-C?

Grind and polish to a mirror finish for sealing/valve faces; no anodizing, plating rarely used, surface passivates naturally in oxidizing service.

ERCoCr-C 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.

ElementSpec limit (wt %)Nominal
Chigh carbon → large primary carbide fraction1.75 – 32.4
Cr25 – 3330
W11 – 1412.5
Ni≤ 3—
Femax (undiluted deposit/rod)≤ 5—
Si≤ 2—
Mn≤ 2—
Mo≤ 1—
Other, total≤ 1—
Cobalance, nominally ~52–55 %balance—

ERCoCr-C-AW — frequently asked

What is ERCoCr-C-AW used for?

ERCoCr-C-AW is typically used for valve trim overlay, exhaust valve facing and wear-resistant weld cladding. In short: intermediate-hardness cobalt hardfacing; 52 HRC wear overlay; grind-only after deposition.

What is the yield strength of ERCoCr-C-AW?

ERCoCr-C-AW has a typical yield strength of 600 MPa (87 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 52% of cobalt-chrome alloy grades. Strength varies by condition: see the 2 listed tempers.

Is ERCoCr-C-AW easy to machine?

Not especially — machinability is rated not recommended (5/100, worse than 82% of cobalt-chrome alloy grades). Effectively unmachinable with carbide — finish by grinding (CBN/SiC wheels), EDM or lapping; leave 0.5–1 mm grind stock on the deposit.

Can ERCoCr-C-AW be welded?

With care — weldability is rated fair (35/100). Deposit by OFW, GTAW, PTA, laser or FCAW with 200–450 °C preheat, controlled interpass temperature and slow cooling; limit passes and expect benign transverse check cracks in wide deposits.

What surface finishes work on ERCoCr-C-AW?

Grind and polish to a mirror finish for sealing/valve faces; no anodizing, plating rarely used, surface passivates naturally in oxidizing service.

Can ERCoCr-C-AW be formed, bent or molded?

No cold forming possible; shape is set by deposition geometry or investment casting of the same chemistry.

What is the maximum service temperature of ERCoCr-C-AW?

ERCoCr-C-AW is rated for continuous use to about 780°C (1,436 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between ERCoCr-C-AW and ERCoCr-C-SR?

AW is the default condition — default reference condition: 2+ layer deposit where substrate dilution no longer affects chemistry — full as-deposited hardness and wear resistance. SR: post-weld stress relief to reduce check-cracking and residual stress in thick or multipass deposits; hardness essentially retained. Yield strength is 600 MPa in AW versus 610 MPa in SR.

Sources

  1. AWS A5.21/A5.21M — Bare Electrodes and Rods for Surfacing — American Welding Society (2011)
  2. ASM Handbook Vol.2 — Properties of Cobalt and Cobalt Alloys — ASM International (1990)
  3. ASM Handbook Vol.6 — Hardfacing and Wear Facing — ASM International (1993)
  4. Stellite 1 / Stellite 12 hardfacing alloy data — Kennametal Stellite / Deloro (2022)

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.