Microalloying method for promoting refining and redissolution of NbX phase in austenitic heat-resistant steel

The invention provides a microalloying method for promoting refining and redissolution of a NbX (X = C, N) phase in austenitic heat-resistant steel, and belongs to the technical field of preparation and application of austenitic heat-resistant steel. The element B easy to segregate to a phase interface is introduced into the austenitic heat-resistant steel, so that the size of the NbX phase is limited, the redissolution temperature of the NbX phase is reduced, and redissolution of the NbX phase is accelerated; in percentage by weight, the element B is less than or equal to 0.008%; the method can inhibit the growth of the NbX phase, limit the size of the NbX phase, promote the dispersion of the NbX phase, reduce the redissolution temperature of the NbX phase and shorten the redissolution time of the NbX phase. 本发明提供了一种促进奥氏体耐热钢中NbX(X＝C,N)相细化、回溶的微合金化方法，属于奥氏体耐热钢的制备与应用技术领域。本发明通过在奥氏体耐热钢中引入容易向相界面偏析的B元素，来限制NbX相尺寸，降低NbX相回溶温度，加速NbX相回溶；按照重量百分比计，元素B≤0.008％；该方法可以抑制NbX相长大、限制NbX相尺寸、促进NbX相弥散，还可以降低NbX相回溶温度，缩短NbX相回溶时间。