Stellite 21 Hard Facing Powder Welding Cobalt Alloy Make Various
Liquid Valves Hot Forging Die
Product Description
WL-Co21 (previously known as WD-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).
WL-Co21 can be cast, powder metallurgically processed, or applied
as a weld hardfacing. It is recommended for applications involving
cavitation, erosion, corrosion and/or high temperatures, such as
valve trim for petrochemical and power generation. Due to its good
impact resistance, it has been widely used in the building up of
forging or hot stamping dies. The oxyacetylene weld deposition
method is not recommended for this alloy.
Common Names: Stellite 21 Polystel 21
Standard: AWS 5.21-2001 ERCoCr-E
CHEMICAL COMPOSITION(%)
| C | Si | Mn | Mo | Cr | W | Ni | Fe | Co |
| 0.25 | 1.50 | ≤0.50 | 5.50 | 27.30 | ≤0.50 | 2.00 | 1.50 | Rest |
Particle size (µm)
180/53, 180/63, 150/45, 150/63, 150/53, 125/38, 250/45, 45/20,
53/20
CHARACTERISITIC
| Abrasion Resistance | Moderate |
| Impact Resistance | Excellent |
| Corrosion Resistance | Good |
| Hardness | HRC 20-35 |
| Deposit Layers | Multiple |
| Deposit Cross Checks | No |
| Magnetic | No |
| Hot Wear Hardness | Good |
| Machineability | Carbide Tools |
Packing Details
Each bottle 5kg/bottles, 5 bottles pack in one carton,
then put cartons onto pallet or Box. OEM packing & label or
customized packing methods available.
APPLICATIONS
Used to make various liquid valves, valve seats
Water turbine blade, hot forging die
Cutting(hot shear)
Impeller(Pump Impellers, Rings)
Type we could offer
| Trademark | Nominal Chemical Composition | HRC | Application |
| C | Cr | Si | W | Ni | Fe | Mn | Mo | Co | B |
| WL Co1 | 2.45 | 30.0 | 1.0 | 13.0 | ≤3.0 | ≤3.0 | ≤1.0 | ≤1.0 | Bal. | | 50-58 | Valve seat insets, bearing, sawteeth, rotary ring, Pump Sleeves |
| WL Co3 | 2.4 | 30.5 | 1.0 | 13.0 | ≤3.0 | ≤3.0 | ≤1.0 | ≤1.0 | Bal. | | 50-56 | Valve seat insets,steel mill guide roll, wearing panel of cracker
blade, etc. |
| WL Co4 | 1.0 | 31.0 | 1.0 | 14.0 | ≤3.0 | ≤1.0 | ≤0.5 | ≤0.5 | Bal. | | 45-50 | Hot extrusion die, dry battery industry |
| WL Co6 | 1.2 | 29.0 | 1.0 | 4.5 | ≤3.0 | ≤3.0 | ≤1.0 | ≤1.0 | Bal. | | 40-46 | Engine valve, high temperature valve, turbine blade |
| WL Co12 | 1.4 | 30.0 | 1.3 | 8.5 | ≤3.0 | ≤3.0 | ≤1.0 | ≤1.0 | Bal. | | 44-50 | Pressure valves, sawteeth screw fights |
| WL Co20 | 2.5 | 32.0 | 1.0 | 17.0 | ≤3.0 | ≤3.0 | ≤0.5 | ≤1.0 | Bal. | | 54-59 | Wear plate, bearing sleeve, etc. |
| WL Co21 | 0.2 | 27.0 | 1.0 | 0.2 | ≤3.0 | ≤2 | ≤1.0 | ≤5.5 | Bal. | | 20-40 | Fluid valve seat, turbine blades, hot forging die |
| WL Co25 | 0.05 | 20.0 | 1.0 | 15.0 | 10.0 | ≤2.0 | ≤1.5 | ≤1.0 | Bal. | | 24 | High temperature and corrosion-resistant valve sealing surface,
pressure casting dies, etc. |
| WL Co31 | 0.5 | 26.0 | 1.0 | 7.5 | 10.0 | ≤3.0 | ≤1.0 | ≤1.0 | Bal. | | 30-35 | Extrusion die, steam turbine blade, etc. |
| WL Co32 | 1.8 | 26.0 | 1.2 | 12.0 | 22.0 | ≤1.5 | ≤0.5 | ≤1.0 | Bal. | | 40-45 | Engine inlet and exhaust valve |
| WL Co190 | 3.2 | 26.0 | 1.0 | 14.0 | ≤1.0 | ≤3.0 | ≤1.0 | ≤1.0 | Bal. | | 54-60 | Petroleum drill bit, mining industry |
| WL CoT400 | 0.08 | 8.5 | 2.6 | | 1.5 | ≤1.5 | ≤1.0 | 28 | Bal. | 0.8 | 50-60 | Valve and roller path, plastic extruder in strongly corrosive |
| WL CoT800 | 0.08 | 18.0 | 3.4 | | ≤1.5 | 1.5 | ≤1.0 | 28 | Bal. | 0.8 | 52-58 | Valve and roller path, plastic extruder in strongly corrosive |
