HomeValve MaterialsStellite 6 (Cobalt-Chromium-Tungsten, UNS R30006)

Valve Material Reference

Stellite 6 (Cobalt-Chromium-Tungsten, UNS R30006) Valve

Stellite 6 Hard-Face Trim

Stellite 6 is a cobalt-chromium-tungsten alloy (Co-28Cr-4W-1C, UNS R30006) applied as a hard-facing weld overlay on valve seats, discs, and plug faces rather than as a bulk body material.

Form

Both

Max Temp

+800°C (+1470°F) as deposited hard-face layer

Min Temp

−196°C (−320°F) — no embrittlement

Category

Non Ferrous

Chemical Composition — Stellite 6 (Cobalt-Chromium-Tungsten, UNS R30006)

Co bal. (~52%), Cr 27–32%, W 3.5–5.5%, C 0.9–1.4%, Ni ≤ 3%, Fe ≤ 3%, Mo ≤ 1%, Si ≤ 2%. Hardness: 36–45 HRC (deposited). UNS R30006.

Temperature Range

Applicable in service from −196°C to +800°C (−320°F to +1470°F) as a surface layer

Maximum Temperature

+800°C (+1470°F) as deposited hard-face layer

Minimum Temperature

−196°C (−320°F) — no embrittlement

Equivalent Grades — Stellite 6 (Cobalt-Chromium-Tungsten, UNS R30006)

StandardEquivalent Grade
Stellite (Kennametal)Stellite 6 / Alloy 6
Deloro / equivalentTribaloy T-400, Colmonoy 6 (similar intent)
ISOISO 14920 cobalt-base hard-face alloys
DINDIN 32529 cobalt hard-surfacing

Suitable Services

High-temperature steam valves above 260°C in power plant service

API 600 gate valves in refinery and petrochemical service per API 600 trim #8, #10, #12

Geothermal and nuclear power plant isolation valves

Metal-seated ball valves in dirty, particulate-laden gas service

Control valve trim in flashing, cavitating, or erosive service

Abrasive slurry lines (mineral processing, cement, coal handling)

Not Suitable For

Bulk valve body construction — Stellite is only a surface-applied trim/seat material

Hydrofluoric acid — cobalt alloys are attacked; use Monel or PTFE

Fuming nitric acid at high temperature

Valve Body Applications

Not used as a body material — applied as a hard-face overlay only

Trim Applications

Seat rings (welded-in or pressed-in) hard-faced with Stellite 6 in API 600 gate valves

Disc hard-face overlay in high-temperature globe and gate valves

Plug hard-face in eccentric plug valves in erosive slurry service

Ball sealing surfaces in metal-seated ball valves for high-temperature service

Control valve cage and plug faces in erosive / flashing service

Typical Valve Types in Stellite 6 (Cobalt-Chromium-Tungsten, UNS R30006)

Gate valves: API 600, Class 300–2500, Stellite-faced seats and wedge

Globe valves: Class 600–1500, Stellite-faced seat rings and discs

Ball valves: metal-seated, Stellite 6-clad seat rings, high-temperature / dirty service

Control valves: Stellite-tipped plugs and cage for anti-erosion / anti-cavitation

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Need Stellite 6 (Cobalt-Chromium-Tungsten, UNS R30006) Valves?

We supply Stellite 6 (Cobalt-Chromium-Tungsten, UNS R30006) (Stellite 6 Hard-Face Trim) gate valves, globe valves, ball valves, check valves, and more. Full certification documentation — EN 10204 3.1/3.2 MTCs, hydro test certs — as standard.