Able to withstand temperatures of up to 2240ºF, stainless steel foil also offers a high strength to weight ratio and resistance to oxidation at high temperatures.
Generally referred to as tool wrap, the most common application of stainless steel foil is to provide increased dimensional stability that helps prevent surface decarburization and other contamination of tool steel parts while they are undergoing heat treatment as well as being cool hardened.
Additional applications of stainless steel foil include shielding for high vacurm applications, x-ray imaging, heating elements and turbine engines. Formed using rolling mills and annealing processed, stainless steel foil can also be used to form stainless steel foil tape, which bonds to most metals and provides advantages such as vapor barrier protection and waterproof sealing.
Common industries that utilize stainless steel foil include manufacturing, medical, automotive, aerospace, defense, petrochemical, laboratory, nuclear and marine. Even though the material is very strong, stainless steel foil can be sheared, perforated or punched in order to better fit the desired application.
Stainless steel foil is typically made from the 200 and 300 series of stainless steel grades, which are all types of austenitic stainless steel. A non-magnetic type of stainless steel, austenitic stainless steel has the highest ratio of chromium and can be used in mild, harsh and corrosive environments. As a result, stainless steel foil is non-magnetic and highly corrosion-resistant.
The most common grades used to make stainless steel foil are 304 and 316. 316 stainless steel is an austenitic alloy that contains 16% chromium, 10% nickel and 2% molybdenum. As a result, 316 stainless steel foil is characterized by its high corrosion resistance as well as having excellent characteristics for forming and welding. 304 stainless steel is the most popular type of austenitic stainless steel and it is comprised of iron, 18-20% chromium and 8-10% nickel.
In addition, 304 stainless steel is easily formed and welded but is not a free-machining material. As a result, 304 stainless steel foil can withstand higher temperatures than aluminum foil as well as being Ultra High Vacuum (UHV) compatible. Additional grades used to form stainless steel foil include 430, 201, 301, 309, 302, 321 and 347.