Abstract: The  transverse  cracks  with  length  10～30  mm  and  maximum  wide  2  mm  at billet  corner  vibrating  mark trough of pickled 300 mm×320 mm low carbon steel cast bloom produced at Xingcheng special  Steel were observed. The  production   practice   indicated   that   as   [Al,]   of   SA-210   series   steel   for   boiler(0.13～0.25C,0.45～1. 10Mn)increased  from  0.009% to  0.021% the  index  of transverse  crack  at  corner  of casting bloom  increased  from  0.03 to 2.64,while with  adding micro titanium in steel the transverse crack at corner of casting bloom decreased obviously as micro titanium is avail able to improve hot forming ability of steel at lower deformation rate. The formation of transverse crack at corner of casting  bloom  of  SA-210C  steel  was  avoided  by  control  adding  Al  amount  to  ensure  [Al,]≤0.010%,adding  Ti  to  get  about  0.02%[Ti],and  adopting  the  operation  measures  such  as  to  increase  molten  steel  flowability  and  cast  bloom  straightening  temperature  ≥900℃.

Key words: Concasting Bloom, Low Carbon Steel, Transverse Crack at Corner, [Al_t], [Ti]

摘要： 兴澄特钢300mm×320mm低碳钢铸坯酸洗后,可观察到铸坯角部振痕波谷处的横向裂纹,其长度为10～30mm,最大宽度达2mm。生产实践表明,当SA-210系列锅炉钢(%:0.13～0.25C、0.45～1.10Mn)的[Al_t]从0.009%增加至0.021%时,铸坯角部横裂纹指数从0.03增加到2.64。因微量钛能改善钢在较低变形速率下的热成型性,钢中加微量钛,可以明显减少铸坯角部横裂纹的产生。通过控制加Al量使[Al_t]≤0.010%,加Ti使[Ti]≈0.02%,同时采用提高钢水流动性和铸坯矫直温度≥900℃等措施,避免了SA-210C钢的铸坯角部横裂纹的产生。

关键词: 连铸方坯, 低碳钢, 角部横裂, [Al_t] , ,  ,  , [Ti]