303F易切削不锈钢Φ9.0 mm盘条的工艺开发与生产实践

易切削不锈钢盘条303F(/%:≤0.15C,≤1.0Si,≤2.0Mn,0.15～0.35S,≤0.045P,17.00～19.00Cr,8.00～10.00Ni,≤0.6Mo)的生产工艺流程为30 t EBT EAF-AOD-LF-150 mm×150 mm CC-高速线材轧制Φ9.0 mm盘条。通过AOD还原熔渣二元碱度1.0～1.4使硫铁中硫的回收率达到70%以上,LF精炼≤45min,能有效防止S]的流失。连铸钢水过热度30～40℃,二冷比水量0.28～0.32 L/kg,选用特定保护渣,能有效的避免絮流,铸坯表面质量良好,连铸坯低倍中心疏松≤2.0级,中心偏析≤2.0级,锭型偏析≤2级,无气孔缺陷。开轧温度1 230～1250℃,终轧温度≥1050℃,进行关水轧制,能有效避免轧制头部开裂。结果表明,303F 钢中硫化物夹杂级别为2.5～3.0级,以MnS夹杂为主。盘条抗拉强度650～670 MPa,晶粒度11～12级,HBW硬度值180～195,车屑呈银灰色的断屑。

Process Development and Production Practice of 303F Free-cutting Stainless Steel Φ9.0 mm Rod

The production process of free-cutting stainless steel 303F (/% : W0. 15C,W1. OSi, W2. 0Mn,0. 15 ~0.35S,≤0.045P,17.00 ?19.00Cr,8.00 ?10.OONi, ≤0.6Mo) wire rod is 30 t EBT EAF-AOD-LF-150 mm x 150 mm CC-Φ9.0 mm Wire Rod High-speed Rolling. By AOD reduction slag binary basicity 1.0 ~ 1.4 ,the yield of sulfur in the iron sulfide reaches more than 70% ,and control LF refining ≤ 45 min, the S] loss can be effectively prevented. With superheat of continuous casting value of 30 ~ 40 °C ,secondary water specific water rate 0.28 ~0.32 L/kg,and using specific protective slag to effectively avoid flocculation, and get good billet surface quality, the center porosity of continuous casting billet is less than 2.0 rating,center segregation≤2.0 rating,ingot type segregation ≤2 rating, no blowhole defects. With breakdown at 1230 ?1250 ℃, final rolling at m 1050 °C and water shut-off rolling the rolling product head cracking can be effectively avoided. The results show that the rating of sulfide inclusions with main MnS in steel 303F is 2.5 ?3.0. The tensile strength of the wire rod is 650 ?670 MPa, the grain size is 11 ~ 12 rating, the value of HBW hardness is 180 ?195, and the turning chips are silver gray broken chips.