高品质超级13Cr不锈钢精炼与铸锭工艺优化

Optimization of refining and ingot casting process on high quality super 13Cr stainless steel

针对超级13Cr不锈钢管坯钢质要求,在VOD真空度小于等于200 Pa下,脱碳沸腾时间由15 min延长到18 min,还原硅铝分开,铝单独在第二批加入;在LF阶段将炉渣中Al_(2)O_(3)质量分数由15%~20%提高到20%~25%,增加3min钢包底吹中搅拌,弱搅拌时间由15 min延长到18 min;模铸发热剂由高热值1530型替代低热值1200型。按生产流程:铁水三脱预处理→90 t K-OBM-S初炼→90 t VOD脱碳→90 t LF调渣→模铸8.4 t钢锭→热轧开坯400 mm×400 mm→径锻管坯→车光→探伤→交库,生产Ф210 mm超级13Cr不锈钢管坯,非金属夹杂物评级达标率由60%提高到100%,探伤合格率由67.5%~79.1%提高到97%~100%,达到电渣重熔水平,省去了电渣重熔,实现了高质量、低成本、批量生产,进一步提高了模铸超级13Cr不锈钢管坯市场竞争力。

According to the requirements of the steel quality of super 13 Cr stainless tubular billet,the decarburization of the boiling was extended from 15 min to 18 min under the condition of VOD vacuum less than or equal to 200 Pa,and the reduced silicon and aluminum were separated,and aluminum was added separately in the second batch.In LF stage,the mass fraction of Al_(2)O_(3) in slag was increased from 15%-20%to 20%-25%,the ladle bottom stirring was increased by 3 min,and the weak stirring time was extended from 15 min to 18 min,and the exothermic compound high calorific value 1530 was used to replace low calorific value 1200.Ф210 mm super 13 Cr stainless tubular billet was produced by the process of hot metal pretreatment→90 t K-OBM-S primary smelting→90 t VOD decarburization→90 t LF adjusting slag→8.4 t ingot→hot rolling blooming 400 mm×400 mm→radial forging→lathing→detecting→delivery,and non-metallic inclusion grading was increased from 60%to 100%,the detection qualified rate increased from 67.5%-79.1%to 97%-100%,achieved the electro-slag level.High quality,low cost and batch process are realized without ESR,and the market competitiveness of super 13 Cr stainless tubular billet has been further improved.