What is the ambient temperature of ASTM A240 steel plate?

ASTM A240 steel plate is suitable for water and other low temperature environments.
Overall corrosion resistance can be reduced by exposure to temperatures ranging from 800 to 1500°F (427 to 816°C). Astm 240 347 steel plates are primarily designed for high temperature sensitization applications and thus prevent intercrystalline corrosion at low temperatures.

Chromium carbide precipates at grain boundaries when ASTM A240 347 steel plates are kept in the range of 800 to 1500°F (427 to 816°C) or are cooled slowly.
In the presence of some highly corrosive medium, these grain boundaries are preferentially eroded, the metal generally weakens, and complete disintegration may occur.