摘要
20CrMnTiH(TS)钢冶金流程为60 t顶底复吹转炉-LF-VD-150 mm×150 mm方坯连铸。钢厂20CrMnTiH(TS)钢夹杂物一次检验不合格率达2.0%,主要为B类(复合钙铝酸盐+镁铝尖晶石,以及部分三氧化二铝)和D类夹杂(钙铝酸盐,部分为复合钙铝酸盐+镁铝尖晶石+氮化钛),尺寸>20μm。通过采用低磷铁水和优质废钢,转炉终点[C]≥0.09%,转炉出钢加40 kg硅钙和40kg钢芯铝替代原只加80kg钢芯铝预脱氧,LF精炼采用SiC70替代SiC45进行扩散脱氧,VD后喂Ti线,保证精炼终渣碱度为3.0,控制连铸时钢包余钢量>2 t等工艺措施使T[O]从12×10^(-6)降至8×10^(-6),一次夹杂物检验不合格率下降至0.5%。
The metallurgical flow sheet for steel 20CrMnTiH （TS） is 60 t top and bottom combined blowing converter- LF- VD- 150 mm~ 150 mm billet casting. The unqualified rate of inclusions in steel 20CrMnTi H（TS） at first examination at steelworks is up to 2% , main inclusions are B series （ compound calcium aluminate ＋ magnesia-alumina spinel, and partial alumina） and D series （ calcium aluminate, and partial compound calcium aluminate ＋ magnesia-alumina ＋ titanium ni- tride）, that size is more than 20 μm. With the process measures including using low phosphorus hot metal and high quality scrap, converter end [ C] ≥0.09% , adding 40 kg silicon-calcium and 40 kg aluminium cladding steel to replace original only adding 80 kg aluminium cladding steel for pre-deoxidation in converter tapping, using SIC70 to replace SIC45 to diffu- sion-deoxidize in LF refining, feeding Ti wire after VD, insuring refining end slag basicity 3. O, and controlling heel liquid more than 2 t, the T[ O] decreases from original 12 × 10 -6 to 8 × 10 -6 and the unqualified rate of inclusions in steel at first examination decreases to 0. 5%.
出处
《特殊钢》
北大核心
2015年第5期39-42,共4页
Special Steel
