Stellite 21 Electrode Weartech WT-21 Hard Facing Electrode Fluid
Valve Seat Turbine Blades
Product Description
WL-Co21 (previously known as WL-Co8) was developed in the mid 1930s
as a corrosion resistant CoCr alloy, and rapidly found application
as a biocompatible hip implant and denture alloy. Many of the
alloys currently used in medical applications are variants of the
original WL-Co21 composition. It was also one of the first
heat-resistant alloys trialled for use in jet engines.
WL-Co21 consists of a CoCrMo alloy matrix containing dispersed hard
carbides which strengthen the alloy and increase its hardness, but
also decrease the ductility. The type, shape, size, and
distribution of the carbides is strongly influenced by the
processing history of the alloy, and for this reason the mechanical
properties of WL-Co21 are very dependent upon the manufacturing
route and any subsequent heat treatments.
Due to the low volume fraction of carbides, the Co-based alloy
matrix dominates the wear and corrosion properties. WL-Co21 has
excellent cavitation, galling and metal-to-metal sliding wear
resistance, but is not recommended for severe hard particle
abrasion. The surface can work harden considerably during wear or
even during machining, and the use of correct machining tools and
techniques is important to achieve optimal results.
WL-Co21 has excellent resistance to thermal and mechanical shock.
Optimum high temperature strength is obtained by solution heat
treatments at 1200-1240ºC (2190 - 2265ºF) followed by quenching,
and aging in the temperature range 7001150°C (1290-2100°F).
Common Names: Stellite 21, BISHILITE (MHA) No.21, Weartech WT-21
Standard:AWS / ASME: A5.13 / SFA5.13 ECoCr-E
Chemical Composition(%)
Co | Cr | Mo | C | Ni | Others |
Bal. | 26-29 | 4.5-6.0 | 0.20-0.35 | 2.0-3.0 | Fe, Si, Mn |
Physical Properties
| Density | Melting Range |
| 27-40 HRC | 8.33 g/cm3 | 1295-1435 ºC |
Specification
AWS / ASME: A5.13 / SFA5.13 ECoCr-E |
| Metal to metal Wear | Excellent |
| Cold / Hot Abrasion | Good / Good |
| Erosion / Corrosion | Excellent / Excellent |
| Impact | Excellent |
| Magnetic | No |
| Deposit Layers | Multiple |
| Thermal Conductivity | 14.5 W/m.K, 100.5 Btu-in/hr/ft2/°F |
| Electrical Resistivity | 87.38 µ-ohm.cm, 34.4 µ-ohm.inch |
Packing Details
For length 350mm 5kg per Vacuum Pack, 1 Vacpak inside a Carton
a carton 4 packs a total of 20kg, then put them in wooden boxes or trays.
Packaging details can also be customized according to customer
requirements.
Applications
It is usd for applications involving cavitation, erosion, corrosion
and/or high temperatures,
such as valve trim for petrochemical and power generation,
biocompatible hip implant and denture alloy,
Fluid valve seat, turbine blades, hot forging die etc.
Type We Could Offer
| Trademark | Nominal Chemical Composition | HRC | Application | Reference Standard |
| C | Cr | Si | W | Ni | Fe | Mn | Mo | Co | others |
| WL Co1 | 2.1 | 30.0 | 1.0 | 14.0 | ≤3.0 | ≤5.0 | ≤2.0 | ≤1.0 | Bal. | <1.0 | 48-54 | Valve seat insets, bearing, sawteeth, rotary ring, Pump Sleeves | St‘ellite 1, ECoCr-C |
| WL Co6 | 1.0 | 29.0 | 1.0 | 4.5 | ≤3.0 | ≤5.0 | ≤2.0 | ≤1.0 | Bal. | <1.0 | 38-44 | Engine valve, high temperature valve, turbine blade | Stellite 6, ECoCr-A |
| WL Co12 | 1.4 | 30.0 | 1.4 | 8.5 | ≤3.0 | ≤5.0 | ≤2.0 | ≤1.0 | Bal. | <1.0 | 44-50 | Pressure valves, sawteeth screw fights | Stellite 12, ECoCr-B |
| WL Co21 | 0.2 | 28.0 | 1.0 | | ≤3.0 | ≤5.0 | ≤2.0 | 5.5 | Bal. | <1.0 | 20-40 | Fluid valve seat, turbine blades, hot forging die | Stellite 21, ECoCr-E |
| WL Co25 | 0.15 | 20.0 | 1.0 | 14.0 | 10.0 | ≤5.0 | ≤2.0 | ≤1.0 | Bal. | <1.0 | 22-40 | High temperature and corrosion-resistant valve sealing surface,
pressure casting dies, etc. | Stellite 25 |
