In 2025, the comprehensive qualification rate of continuous casting blooms at the Steelmaking Plant of Xingtai Iron & Steel reached 99.95%, a record high and comfortably exceeding the corporate budget target of 99.77%. As a core gauge reflecting bloom quality and rolling performance, the comprehensive qualification rate covers not only the surface quality of cast blooms but also imposes stringent requirements on internal inclusions and gas content after rolling. Centered on this key target, the steelmaking plant rolled out a full suite of refined management initiatives and technical upgrades targeting improvements in both surface finish and internal cleanliness of cast blooms.

To upgrade the surface quality of cast blooms, the plant rigorously enforced the grade-specific supervisor accountability system and set up dedicated taskforces to tackle corner cracking issues for hot-rolled Cr-Mo steel blooms and Grade A peritectic steel, alongside teams tasked with quality optimization of bearing steel and spring steel cast blooms. Meanwhile, mould flux management was refined by classifying mould fluxes into low-carbon grade, peritectic steel grade, boron-bearing low-carbon grade and other categories matching respective steel grades, effectively curbing quality fluctuations triggered by mismatched mould flux performance.

For enhanced molten steel cleanliness, the plant pushed forward process optimization and equipment retrofitting. It independently developed an RH nitrogen boosting process for 30MnVS6 and S20A steels, which greatly improves molten steel cleanliness while securing targeted nitrogen content. A string of upgrades including argon sealing modification on LF furnace hoods, argon seal revamp for ladle long nozzles and custom-built argon-shrouded tundish covers helped steadily cut nitrogen levels in conventional steel grades. The qualification rate for nitrogen content ≤50ppm has stayed above 85%, peaking above 95% in certain months.

Furthermore, the plant standardized operational workflows and enriched emergency contingency plans. Throughout 2025, six quality contingency documents were revised and four new operational specifications were compiled, markedly lifting quality reliability amid abnormal and non-steady production conditions. Thanks to the full implementation of above measures, the bloom comprehensive qualification rate has climbed steadily, laying a solid footing for the company’s high-quality development.