In order to adapt to the harsh service environment of 700 ℃ advanced ultra-supercritical coal-fired power generation unit(700 ℃ A-USC)

and facilitate the development of high efficiency

low consumption and low carbon coal-fired power generation technology

high temperature superalloy will be used to manufacture the high-temperature components in boiler and turbine. Many countries and regions such as the United States

Europe

China

Japan and India have put forward research plans of 700 ℃ A-USC technology with national characteristics

respectively. Due to the variety of elements

high welding difficulty

and high tendency to produce welding defects in high-temperature alloys

welding technology and weld joint comprehensive performance evaluation technology have a significant influence on the factory manufacturing

on-site processing and repair

as well as service safety and integrity of high-temperature components. The current progress in practical application of the 700 ℃ technology at home and abroad is slow

which is mainly due to incomplete resolution of technical barriers such as manufacturing

connection

and testing. The research plans and development prospects of the 700 ℃A-USC technology around the world are summarized. The material selection of high temperature components including the boiler side and the turbine side is discussed. The current status

advantages and disadvantages of the welding technology for superalloy are summarized

and the critical focus points of the joint comprehensive properties evaluation technology for high temperature components are analyzed. Finally

some suggestions on developing the 700 ℃ A-USC technology are put forward.