Could you please tell me what is the temperature range of cryogenics? In other words, is -100°F considered cryogenic, or does it start lower? Could I expect to see some extended life in D2 stamping dies? What would the recipe be to achieve the desired results using cryogenics?
3 Comments
Peter Kittel
August 1, 2008Cryogenics is generally considered to be below 120 Kelvin (120K or -153C).
James Fesmire
August 1, 2008The temperature range of cryogenics is generally considered to be about -260°F (methane normal boiling point) down to -460°F (absolute zero). The more conventional refrigerants operate in the range of -20°F down to -200°F.
Dr. Randall F. Barron
August 1, 2008There is not really a sharp dividing line between the ‘cryogenic’ temperature range and those temperatures used in ‘refrigeration’. The prefix ‘cryo’ comes from the Greek kryos, meaning ‘icy cold’, so cryogenics is the area involving ‘very low’ temperatures, whatever that means.
A fairly widely accepted dividing line for cryogenics is that ‘cryogenics’ involves the temperature levels below minus 150°C (-238°F or 123K). According to R.B. Scott, Cryogenic Engineering, D. van Nostrand Co., Princeton NJ, (1959), pg. 1: ‘It is rather difficult to assign a definite temperature which will serve as the dividing point between refrigerating and cryogenic engineering, but it will probably conform to present usage to say that cryogenic engineering is concerned with temperatures below -150°C.’
Also, from K.D. Timmerhaus and T.M. Flynn, Cryogenic Process Engineering, Plenum Press, New York, (1989), pg. 1: ‘The lower end of the cryogenic scale is conveniently fixed at absolute zero. The upper end of the cryogenic region is less specific but certainly less than any natural temperature recorded on earth. Minus 150°C, where some common gases condense and form liquids, is a useful working value.’
You had asked whether -100°F (-73°C or 200K) would be considered ‘cryogenic’. This temperature can be achieved by R-12 at 1.44 psia or 0.10 atm. R-12 is not considered to be a cryogenic fluid. Also R-22 can reach -100°F. at 2.4 psia or 0.17 atm, and R-22 is considered to be (although now outlawed) an ‘ordinary’ refrigerant. Thus, technically speaking, -100°F is not within the cryogenic temperature range.