Welding performance analysis of ultra (ultra) supercritical thermal power units T91 and TP347H

Two kinds of heat-resistant steel,T91 and TP347H-overseas production ferrite SA213-T91 (domestic GB5310-T91) and overseas production austenite SA213-TP347H,are applied to the reheater,the superheater,the economizer,the main steam pipeline and the header of boiler heating surface,which the boiler withstands the supercritical pressure and the ultra 570℃ high temperature in manufacture and installment first-phase 2×600 MW coal-fired generating units in China-HK (Hong Kong) joint project through the Zhuhai Power plant. The metal characteristics and welding performance of the two kind steels are analyzed,and the primary factors of producing crack,corrosion and embrittlement flaw in the boiler production and the movement process are determined by experiments,and the craft evaluation of the parent metal and the welding material has carried out by using the corresponding craft measure. The fine weld joints are obtained,which will promote the using of the T91 and TP347H heat-resistant steel in the manufacture of the promotion (ultra) supercritical pressure thermal power unit boiler.