When you need to heat tool steel parts inside a regular furnace, you need an effective way of preventing oxygen reactions at high temperatures. Stainless steel wrap foil is your trusted helper in such situation, as it can be easily made into an airtight envelope for the component to be heated. Read below the handy tips that can ensure flawless results:
- The best way to seal it
Once you have carefully wrapped the foil around the tool, you need to seal it edges. First of all, decide to leave a vent of maximum 5-6 mm, to avoid breakage due to air dilatation. Anything larger than this will let in too much air. Proceed to sealing the edges with a double fold.
- Careful handling
Steel tool wrap foil is very flexible and can take many shapes, but it can also be torn with ease. Protect it from punctures and tearing through a careful maneuvering. You may press to make the air in the package come out, but not too much, since this can damage the foil.
- Check the metallurgical standard
As steel comes in many types, each with different properties, so is tool wrap foil. Check with the manufacturer to determine its exact use and resistance. Not any stainless steel heat treatment foil may resist to the temperatures you work with, for example. There are different foil grades – make an informed choice.
- Preventing discoloration
Discoloration of components is a real issue when processing these in high temperatures. Luckily, foil wrapping will protect the from this unwanted effect, not just from decarburisation. The surface will be unaltered.
- Adjusting the temperature
Stainless steel foil is made to resist temperatures of over 1,000 degrees Celsius and 2,000 F. Because it has an isolation effect, you can safely increase the temperature a bit when heating parts, if you notice the standard level is not enough.
Remember you should only use stainless steel tool wrap with air hardening steel. Manufacturers do not recommend it for other types. If you are working with a vacuum or controlled atmosphere furnace, then the foil is no longer needed.