Abstract: The Φ600 mm cast bloom of 4130X steel ( /% ：0. 31C, 0. 26Si, 0. 80Mn, 0. 008P, 0. 003S, 0. 99Cr, 0. 21Mo, 0.005Ti, 0.023Al) is produced by the technological route of umolten iron→vanadium extraction converter→pretreatment desulfurization→70 t converter→LF→VD→Ground bloom continuous casting→slow cooling". By control [ P ] ≤ 0. 140% , [ S ]≤0.070% in hot metal; KR pretreatment after vanadium extraction in converter, KR stirring speed 80 r/min for 15 min, and KR end [ S ]w0. 005% ; converter end point 0. 06% ~0. 10% C, end point [ P ] ≤0.008% , tapping steel temperature m 1 620 ℃ , and using slide plate slag blocking technology; LF using high Al refining slag system, with the initial slag 40% ～45%( CaO ), 10% ～15%( SiO₂ ),the final slag 35% ～40%( Al₂O₃ ),50% ～55%( CaO ), 5% ~15%( SiO₂ )；VD Ca treated to control 0. 000 5% ~ 0. 001 0% [ Ca ], the vacuum degree less than 67 Pa for ≥18 min, and the soft blowing time ≥20 min; in the process of continuous casting, using the mould ( 200 A/2. 0 Hz ) + solidification end electromagnetic stirring ( 900 A/6. 0 Hz ) combined stirring mode, the superheat 20 ～30 °C , the constant drawing speed 0. 21 m/min, and the secondary cooling specific water volume 0. 08 L/kg, the Φ600 mm casting bloom of 4310X steel for large volume seamless gas cylinder is successfully developed with class A and class D inclusions in steel ≤1. 0 grade, class B and class C inclusions 0, class Ds ≤l. 5 grade, and all the indicators to meet the requirements of users.

摘要： 采用"铁水→提钒转炉→预处理脱硫→70 t转炉→LF→VD→圆坯连铸→缓冷"的工艺流程生产4130X钢(/%:0.31C,0.26Si,0.80Mn,0.008P,0.003S,0.99Cr,0.21Mo,0.005Ti,0.023Al)Φ600 mm铸坯。通过控制铁水中P≤0.140%,S≤0.070%;转炉提钒后采用KR法进行预处理,KR搅拌速度≥80 r/min,搅拌时间15 min,控制KR出站S≤0.005%;转炉终点0.06%～0.10%C,终点P≤0.008%,出钢温度≥1 620℃,并采用了滑板档渣技术; LF采用高Al精炼渣系,初渣40%～45%(CaO),10%～15%(SiO₂),控制终渣35%～40%(Al₂O₃),50%～55%(CaO),5%～15%(SiO₂); VD Ca处理,控制钢中Ca含量0.000 5%～0.001 0%;真空度≤67 Pa,≥18 min,软吹≥20 min;连铸过程中采用结晶器(200 A/2.0 Hz)+凝固末端电磁搅拌(900 A/6.0 Hz),过热度20～30℃,拉速0.21 m/min,二冷比水量0.08 L/kg,成功研发出大容积无缝气瓶用4130X钢Φ600 mm连铸坯,钢中A、D类夹杂物均≤1.0级,B、C类夹杂物均为0,Ds类≤1.5级,所有指标均满足用户要求。

关键词: 无缝管用 4130X 钢, Φ600 mm 铸坯, 冶炼及浇注工艺, 生产实践