关键词: Φ1 200 mm, 大截面连铸圆坯, 弧形连铸机

Abstract: Φ1200 mmS355NL/Q355NE steel (Ceq0.38-0.41) continuous casting round bloom is manufactured by 100 t KR-BOF-LF-RH-R18M continuous casting process. Full protective casting, precise cooling process, three-stage electro- magnetic stirring, slow cooling process and other technical measures are adopted. The superheat is controlled at 1545 ℃, the drawing speed is 0.14-0.20 m/min, the electromagnetic stirring is 300 A/2 Hz, the secondary cooling water ratio is 0.20 L/kg, the slow cooling time into the pit is ≥72 h, and the pit exit temperature is ≤300 ℃. The results show that [0]≤0.0018%,[H]≤0.00008%; the central porosity of cast bloom≤1.5  rating, the central crack≤1.5 rating, the shrinkage cavity ≤0.5 rating, and the carbon content range of the whole section≤0.07%. Chemical composition, macrostruce, surface quality all meets the standard requirements. After the round bloom is forged into wind turbine flanges with wall thickness of 450-550 mm by customer, the test results of inclusions, mechanical properties, internal flaw detection and other quality indexes are satisfactory, which fully meet the technical specifications and user requirements.

Key words: Φ1 200 mm, Large Section Round Bloom, Arc Continuous Caster