S45C、S55C等优质碳素结构钢广泛应用于汽车零部件加工,而S45C连铸坯碳偏析情况较严重,极差较大,碳含量呈"M"形分布,导致零件在后续热处理过程中变形程度较大,严重影响装配精度.为进一步探究影响连铸坯碳偏析的因素,通过实验验证结晶器电磁搅拌参数、二冷比水量及末端电磁搅拌参数对连铸坯碳偏析的影响效果.结果表明,在拉速为0.75 m/min,过热度为15～30℃的情况下,当结晶器电磁搅拌参数为150 A/3 Hz、二冷比水量为0.27 L/kg、末端电磁搅拌参数为350 A/6 Hz时,S45C钢碳偏析控制效果最好,C含量极差的分布范围为0.027%～0.037%.将此连铸工艺参数应用于生产S55C钢,除1炉因过热度较高导致C含量极差达到0.04%外,其他炉次C含量极差均控制在0.025%～0.035%范围内,极大地提升了铸坯均质化水平.经感应加热处理后的零件尺寸变形稳定,最大变形量均不高于0.05 mm.
Research on composition homogenization of high-quality S45C continuous casting billet for automobile
High-quality carbon structural steels such as grade S45C and S55C are widely used in automobile parts manufacturing.However,relatively serious carbon segregation of S45C continuous casting billets,with a large range and a M-shaped distribution led to significant deformation of the parts during subsequent heat treatment,seriously affecting assembly accuracy.For further study of the influencing factors of carbon segregation in continuous casting billet,a series of experiments have been conducted to verify the effect of the following factors on carbon segregation in continuous casting billets:parameters of mold electromagnetic stirring,water ratio in secondary cooling,and solidification end electromagnetic stirring parameters.The results showed that the carbon segregation control effect of S45C steel was best at a casting speed of 0.75 m/min,superheated of 15-30℃,mold electromagnetic stirring parameters of 150 A/3 Hz,water ratio in secondary cooling of 0.27 L/kg,and terminal electromagnetic stirring parameters of 350 A/6 Hz,with a carbon content range of 0.027%-0.037%.Applying this continuous casting process parameter to the production of S55C steel,due to the high superheated,the carbon content in one furnace reached a range of 0.04%,while the range of carbon content in other furnaces was controlled between 0.025%to 0.035%,greatly improving the homogenization level of the casting billet.The deformation of the automobile parts after induction heating treatment is stable,and the maximum deformation is not higher than 0.05 mm.
S45C steelthe range of carbon contentM-EMSball cage steel
万方数据
维普
