Cobalt-Chrome Alloy ERCoCr-C-SR (Stress relieved)
Heat-treated state
UNS R30012
Post-weld stress relief to reduce check-cracking and residual stress in thick or multipass deposits; hardness essentially retained.
Values for the SR condition
Other ERCoCr-C tempers and conditions
ERCoCr-C is listed in 2 conditions; see the grade overview at ERCoCr-C.
- AW
- SR
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AWDefault As-welded deposit | Default reference condition: 2+ layer deposit where substrate dilution no longer affects chemistry — full as-deposited hardness and wear resistance. | 600 | 620 | 0.5 | 52 HRC | 1.8 % IACS |
SRThis page Stress relieved | Post-weld stress relief to reduce check-cracking and residual stress in thick or multipass deposits; hardness essentially retained. | 610 | 650 | 0.8 | 51 HRC | 1.8 % IACS |
What is ERCoCr-C-SR?
ERCoCr-C-SR is ERCoCr-C heat treated to SR — post-weld stress relief to reduce check-cracking and residual stress in thick or multipass deposits; hardness essentially retained. ERCoCr-C-SR has a yield strength of 610 MPa (88.5 ksi) and a tensile strength of 650 MPa (94.3 ksi) — stronger than 58% of cobalt-chrome alloy grades. Elongation at break is 0.8% and the elastic modulus is 250 GPa (36.3 Msi). ERCoCr-C-SR 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). AW is the default condition FabDigit quotes; SR is available on request or by drawing note.
Limitations
- Limited ductility — 0.8%, worse than 78% of cobalt-chrome alloy grades
ERCoCr-C-SR properties
Typical room-temperature values for ERCoCr-C-SR; 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-SR 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).
Mechanical16
ERCoCr-C-SR has a yield strength of 610 MPa (88.5 ksi) and a tensile strength of 650 MPa (94.3 ksi) — stronger than 58% of cobalt-chrome alloy grades. Elongation at break is 0.8% and the elastic modulus is 250 GPa (36.3 Msi).
Thermal5
ERCoCr-C-SR is rated for continuous service to 780°C (1,436 °F). It conducts heat at 15 W/m·K (8.67 BTU/hr·ft·°F), better than 96% of cobalt-chrome alloy grades. Thermal expansion is 11 µm/m·K (6.11 µin/in·°F).
Electrical3
ERCoCr-C-SR conducts electricity at 1.8 % IACS, worse than 75% of cobalt-chrome alloy grades.
Chemical & Environmental2
Corrosion resistance is very good (70/100), worse than 71% of cobalt-chrome alloy grades.
Sustainability3
Producing a kilogram of ERCoCr-C-SR 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%.
Manufacturability8
ERCoCr-C-SR's machinability is not recommended (6/100, worse than 75% of cobalt-chrome alloy grades); weldability fair (40/100); formability not recommended (3/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ERCoCr-C-SR
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.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Chigh carbon → large primary carbide fraction | 1.75 – 3 | 2.4 |
| Cr | 25 – 33 | 30 |
| W | 11 – 14 | 12.5 |
| Ni | ≤ 3 | — |
| Femax (undiluted deposit/rod) | ≤ 5 | — |
| Si | ≤ 2 | — |
| Mn | ≤ 2 | — |
| Mo | ≤ 1 | — |
| Other, total | ≤ 1 | — |
| Cobalance, nominally ~52–55 % | balance | — |
ERCoCr-C-SR — frequently asked
What is ERCoCr-C-SR used for?
ERCoCr-C-SR 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-SR?
ERCoCr-C-SR has a typical yield strength of 610 MPa (88.5 ksi) and a tensile strength of 650 MPa (94.3 ksi) — stronger than 58% of cobalt-chrome alloy grades. Strength varies by condition: see the 2 listed tempers.
Is ERCoCr-C-SR easy to machine?
Not especially — machinability is rated not recommended (6/100, worse than 75% 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-SR be welded?
With care — weldability is rated fair (40/100). 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-SR?
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-SR 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-SR?
ERCoCr-C-SR 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
- AWS A5.21/A5.21M — Bare Electrodes and Rods for Surfacing — American Welding Society (2011)
- ASM Handbook Vol.2 — Properties of Cobalt and Cobalt Alloys — ASM International (1990)
- ASM Handbook Vol.6 — Hardfacing and Wear Facing — ASM International (1993)
- 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.