Retracted: Dissolution Behavior of Boron Nitride Inclusions and Segregation of Nb Element in Martensitic Ferritic Steel.

The solid solution strengthening of the B and N elements improves the creep resistance of the CB2 cast heat‐resisting steel, and the formation of boron nitride (BN) plays an important role in the strengthening results. The elimination of BN inclusions is usually the focus of BN research in steel, and the dissolution process of BN inclusions and the effect on Nb‐containing nitrides are ignored. Herein, secondary ion mass spectrometry (SIMS) and scanning electron microscopy (SEM) are used to study the changes of morphology and size of BN with temperature, and the mechanism of the influence of BN dissolution on the strength and ductility of CB2 steel is revealed. The BN particles having sharp corners become hollow spheres and then disappear when the temperature is raised from 1100 to 1200 °C. The dissolution of BN in CB2 steel is accompanied by an increase in strength and plasticity. When 1200 °C is selected as the heating temperature, the tensile strength and yield strength of CB2 steel are significantly increased. Furthermore, significant segregation of the niobium element occurs in the final stage of dissolution of BN inclusions. As the BN dissolves, the segregation of the Nb element is promoted. [ABSTRACT FROM AUTHOR]