Alloy Wire International
Datasheet: Heatseal 29
Heatseal 29
A Nickel-Iron-Cobalt alloy having a controlled expansion coefficient. Its expansion with temperature rise is less than that of 80/20 NiCr.
Available in all profile options
Key Features
Having low expansion as it’s temperature increases makes it an ideal heating element wire for heat sealing (plastic bag welding) over a long straight length.
Typical Applications
Heat sealing (plastic bag welding) long lengths of plastic bags where low expansion of the wire is important to ensure straightness of the weld.
Examples include heat sealing plastic bags for bed mattress’s.
Designations
AWS 094
Chemical Composition
| Element | Min % | Max % |
|---|---|---|
| Fe | 53.00 nominal | |
| Ni | 29.00 nominal | |
| Co | 17.00 nominal | |
| Mn | – | 0.50 |
| Si | – | 0.20 |
| C | – | 0.04 |
| Al | – | 0.10 |
| Mg | – | 0.10 |
| Zr | – | 0.10 |
| Ti | – | 0.10 |
| Cu | – | 0.20 |
| Cr | – | 0.20 |
| Mo | – | 0.20 |
Alloy Details
| Density | Melting Point | Inflection Point | Thermal Conductivity | Coefficient of Expansion |
|---|---|---|---|---|
| 8.16 g/cm³ | 1450 °C | 450 °C | 16.7 W/m• °C | 6.0 µm/m °C (20 – 100 °C) 4.6 – 5.2 µm/m °C (20 – 400 °C) |
| 0.295 lb/in³ | 2640 °F | 840 °F | 116 btu•in/ft2•h °F | 3.3 x 10-6 in/in °F (70 – 212 °F) 2.6 – 2.9 x 10-6 in/in °F (70 – 752 °F) |
Heat treatment of finished parts
| Condition as supplied by Alloy Wire | Type | Temperature | Time | Cooling |
|---|---|---|---|---|
| Anneal | 850 – 1000 °C (1560 – 1830 °F) | 0.5 Hr | Air or water | |
| To prepare for glass to metal sealing | Decarburization | 900 – 1050 °C (1650 – 1920 °F) | 1 Hr | Air or water |
| If a metal oxide interface is required (time and temperature depend on required oxide thickness) | Oxidize | 600 – 1000 °C (1110 – 1830 °F) | 1 Hr | Air |
The alloy is usually supplied and used in the annealed condition (residual cold work distorts the coefficients of thermal expansion.) Annealing times may vary due to section thickness. Oxidising time and temperature to be selected depending on required oxide thickness.
Properties
| Annealed | ||
|---|---|---|
| Approx. tensile strength | <550 N/mm² | <80 ksi |
| Approx. operating temperature | up to +400 °C | up to +750 °F |
| Hard Drawn | ||
|---|---|---|
| Approx. tensile strength | 700 – 900 N/mm² | 102 – 131 ksi |
| Approx. operating temperature | up to +400 °C | up to +750 °F |
The above tensile strength ranges are typical. If you require different please ask.
