Postalloy® 2521-B
Postalloy® 2521-B is a cobalt base hardfacing alloy offering good strength and toughness at elevated temperatures up to 1500 °F (816 °C), and is used for weld overlaying of hot-working dies and valves. A low carbon content weld deposit with dispersed hard carbides provide excellent resistance to thermal shock, galling, corrosion, and cavitation erosion. These deposits are strengthened by the addition of molybdenum and are very stable in thermal cycling environments.
- Weld deposits exhibit superior resistance to heat checking, spalling and chipping.
- Excellent resistance to corrosive environments, and outstanding resistance to cavitation, erosion and thermal shock.
- Resists oxidizing and reducing atmospheres up to 2100 °F (1149 °C).
- Postalloy® 2521-B also provides excellent resistance to corrosive environments.
Specifications
Product Type
- Tig
- Oxy-fuel
- Cobalt Base Hardfacing Alloy
Applications
- Forging dies, Hot trimming dies, Hot shears, Cavitation repair, chemical and petrochemical valves, Forging dies, Steam and fluid control valve bodies and Seamless pipe piercing mandrels.
Weld Deposit Properties
- Hardness as Welded:
- 30-35Rc
- Work hardens over 40Rc
- Deposits have very little tendency to relief check
- Deposit Thickness:
- 2 layers
- Machinable:
- Fully machinable
Welding Parameters
Current Type: DC Electrode Negative
| Volts | Amps | Gas | Tig |
|---|---|---|---|
| 15-25 | 50-80 | 100% Ar | .045" (1.2mm) |
| 15-25 | 55-90 | 100% Ar | 1/16" (1.6mm) |
| 15-25 | 75-100 | 100% Ar | 3/32" (2.4mm) |
| 15-30 | 90-120 | 100% Ar | 1/8" (3.2mm) |
| 15-30 | 120-140 | 100% Ar | 5/32" (4mm) |
| 15-30 | 140-160 | 100% Ar | 3/16" (4.8mm) |
| Oxyacetylene | Tip Size | Flame |
|---|---|---|
| .045" (1.2mm) | 3 | 3x-4x |
| 1/16" (1.6mm) | 3-4 | 3x-4x |
| 3/32" (2.4mm) | 3-4 | 3x-4x |
| 1/8" (3.2mm) | 4 | 3x-4x |
| 5/32" (4mm) | 4 | 3x-4x |
| 3/16" (4.8mm) | 5 | 3x-4x |
Welding Procedure:
Packaging Options
| Diameter | Standard Packaging |
|---|---|
| All Diameters | 10 lb (4.54kg) tubes |