The first domestically produced FB2 medium pressure rotor of the world's largest grade, developed by China National Machinery Corporation, has been successfully shipped, marking China's successful capture of the key core technology for the entire process of FB2 medium pressure rotor forgings in million kilowatt ultra supercritical units. It has successfully achieved the import substitution of FB2 materials for a full series of rotor forgings, providing a hard core support for ensuring the security of the national energy equipment industry chain supply chain. It is reported that the FB2 medium pressure rotor delivered this time is a key core component of the highest temperature level 1000 MW ultra supercritical unit currently in commercial operation. It weighs more than 50 tons and has a diameter of over 1200 millimeters. It is currently one of the heaviest and largest martensitic heat-resistant steel rotor forgings in the world. It will be used in the 1000 MW 620 ° C ultra supercritical secondary reheat unit, further accelerating the localization engineering application of FB2 rotors, which has significant practical significance and far-reaching impact. (Lai Xin She)