Metal Materials Application Analysis of 700℃ Level Advanced Ultra-Supercritical Coal-Fired Boiler

Different countries began to research advanced ultra-supercritical(A-USC)power generation technology in recent years.The design temperature and pressure of AUSC boiler had improved to 700℃ and 35 MPa.In the meantime,the high temperature strength,oxidation-resistance,corrosion-resistance and weld-ability of metal materials should be improved.To the A-USC unit research programs of main countries,the paper presented the microstructure,the mechanical properties and the researching progress of main materials which were used to fabricate superheater and main steam pipe.These Nibased high temperature alloys contained Inconel617,Haynes230,Inconel617 B,Nimonic263and Inconel740.In the last,some suggestions were mentioned to select Ni-base alloy for researchers and users.