Microstructure and Strengthening Mechanisms of HCM2S(T23) Steel
Microstructure and strengthening mechanisms of T23 steel used for superheater tube has been investigated by means of carbon replica method,transmission electron microscopy,SEM and EDS.The results showed that the microstructure of T23 by normalizing processing is granular bainite.For granular bainite steel,not only grain boundary and substructure strengthening,solution strengthen,but also dispersion strengthening of M/A island are effective.The microstructure of T23 under tempered after normalizing conditions is tempered granular bainite.For tempered granular bainite steel,The major portion of M/A islands decompose into carbide and ferrite.And a great deal of fine granular deposited MX phase precipitate in the intragranular and intergranular fields of T23 steel.The strengthening mechanism of T23 steel include the solution strengthening,grain boundary and substructure strengthening and the precipitation strengthening plays a significant role in strengthening mechanism.