Not A333Cr6 it should be A333Gr6, ASTM A333/A333M "cryogenic equipment standards of seamless and welded steel" level (Grade) 6, the chemical composition of C ≤ 0.30%, Mn :0.29-1 .06%, P ≤ 0.025 %, S ≤ 0.025%, Si ≥ 0.10%; yield strength ≥ 240MPa, a tensile strength ≥ 415Mpa; the material minimum impact test temperature of -45 ° C. Due to for steel A333Gr6, the individual is more recommended GTAW + SMAW (argon ITU welding) process the wire election TGS-1N, electrode selection W707Ni. This welding consumables matching has been used in more than one of the Refinery and Petrochemical Plant Construction, is a relatively mature.