ASTM A516 Gr 70 steel for moderate and low temperature service is required to provide high strength, ductility, and toughness in pressure vessels that must serve at -45°C and lower.
ASTM A516 Gr 70 steel plates are applicable for the construction of power boilers (ASTM BPVC Section I), nuclear power plant components (ASTM BPVC Section III Classes 2 & 3), pressure vessels (ASTM BPVC Section VIII Divsion 1), and transport tanks (ASTM BPVC Section XII). According to ASTM BPVC Seciton II, the maximum temperature limits and its application for ASTM A516 Gr 70 steel plates are listed respectively:
ASTM Section I: 850°F
ASTM Seciton III CL 2 & 3: 700°F
ASTM Section VIII-1: 1000°F
ASTM Section XII: 650°F
Generally ASTM A516 Gr 70 steel plates have no problem above -45°C if the requirements of ASTM Code are satisfied (like bhushan76 say). In any case, with -50 °C, you must have an impact test at minimum -50 °C and you have to choose the value required (Joule) by the code (or by PED Dyrective if you have to use it).
