Q. Define Carbon steel?

At ambient temperatures and under dry conditions, caustic is not particularly corrosive and can be handled in carbon steel. However, stress corrosion cracking may occur at various concentrations at elevated temperatures. Since tensile stress is required for stress corrosion cracking, the potential for SCC will be reduced by stress relieving heat treatment following forming and welding. Aqueous caustic solutions up to 50% concentration and 122°F (50°C), can be handled in non-stress relieved carbon steel.