本发明涉及一种制备先进超超临界含B的9Cr耐热钢的工艺，其采用真空碳脱氧加负压渗氮熔炼工艺结合电渣重熔冶炼工艺，先通过控制冶炼气氛和合金化顺序，得到合金元素含量均在目标范围内的铸锭，进行锻造成型，得到作为电渣重熔冶炼的电极，然后将该电极用于电渣重熔冶炼工艺，通过对电渣重熔过程中的渣系成分和冶炼气氛进行控制，得到化学成分均在目标范围内的电渣锭，该电渣锭可用于锻造成所需的9Cr耐热钢工件。本发明能够精确控制电渣重熔电极的化学成分和质量，从而使实现电渣重熔铸锭的冶金质量的可控性和稳定性，能有效控制含B的9Cr耐热钢中的O，N及已氧化合金元素含量控制在目标范围内，提高9Cr耐热钢的冶金质量。

The invention relates to a process for preparing advanced ultra supercritical 9Cr heat-resistant steel containing B, which adopts vacuum carbon deoxidation plus negative pressure nitriding smelting process combined with electroslag remelting smelting process. Firstly, by controlling smelting atmosphere and alloying sequence, ingots with alloy element content within the target range are obtained, forged and formed to obtain electrodes for electroslag remelting smelting, Then the electrode is used in the electroslag remelting smelting process. By controlling the slag system composition and smelting atmosphere in the electroslag remelting process, an electroslag ingot with chemical composition within the target range is obtained. The electroslag ingot can be used to forge the required 9Cr heat-resistant steel workpiece. The invention can accurately control the chemical composition and quality of electroslag remelting electrode, so as to realize the controllability and stability of metallurgical quality of Electroslag Remelting Ingot, effectively control the content of O, N and oxidized alloy elements in 9Cr heat-resistant steel containing B within the target range, and improve the metallurgical quality of 9Cr heat-resistant steel.