Weldability and properties of joints welded in the new-generation creep-resistant steels: T/P23 steel

Abstract

Higher steam parameters employed in boilers to increase the efficiency of power units and a reduction in the quantity of impurities emitted to the atmosphere jointly increase the level of demands put on the steels, of which elements of tubeplates are made. The 1Cr–1/2Mo steels now being used do not meet these requirements. Apart from the requirement for increased resistance to creep, any new-generation steel should also make possible to welding of tubeplates without the need for post-welding heat treatment of the produced joints. The increased requirements have led to the development of HCM2S (T23) steel in Japan. Encouraging results of the investigations into the HCM2S steel have widened the scope of applications of this particular grade to the large diameter, thick-walled tubing (P23 pipe).