【作者】 范建文； 张磊； 陆恒昌； 董瀚； 杨伟宁； 赵秀明；

【Author】 Jian-wen FAN;Lei ZHANG;Heng-chang LU;Han DONG;Wei-ning YANG;Xiu-ming ZHAO;Central Iron&Steel Institute;University of Science and Technology;Nanjing Iron&Steel Co.Ltd.;Nanjing Institute of Technology;

【机构】 钢铁研究总院； 北京科技大学； 南京钢铁股份有限公司； 南京工程学院；

【摘要】 对由转炉/电炉两种不同工艺流程生产的F40VS非调质钢中的硫化物,采用多种方法定量检验分析并推断其起源。结果表明,(1)钢中硫化物主要是凝固过程析出的(Mn,Fe)S夹杂物和以内生夹杂为核心形成的以(Mn,Fe)S为主的硫化物,且前者数量是后者的4-13倍,此外还包括以内生+卷渣夹杂为核心、以MgO耐材卷渣为核心形成的以(Mn,Fe)S为主的硫化物,以内生夹杂为核心形成的以CaS为主的硫化物;(2)转炉流程生产的F40VS钢中,以内生夹杂物为核心形成的以(Mn,Fe)S为主的硫化物夹杂数量是电炉钢的4倍;(3)等积圆直径5微米以上的硫化物,凝固过程析出硫化物和以内生夹杂物为核心形成长大的硫化物比较,前者无论尺寸还是轴比均大于后者。在此基础上,对该非调质钢硫化物的控制方法探讨并提出了建议:(1)降低钢中氧含量;(2)加强精炼末期的Ca处理,提高以内生夹杂物为核心形成的硫化物数量;(3)降低连铸过热度,强化结晶器电磁搅拌,以细化铸坯组织减少枝晶偏析。更多还原

【Abstract】 Sulphide inclusions in F40 VS micro-alloyed steel products manufactured with the BOF and the EAF process have been tested and analyzed by some methods respectively,and the generation mechanisms of sulphide have been inferred.The results show that sulphide inclusions mainly consist of(Mn,Fe)S originating during the solidification process from saturated precipitation and nucleation and growth on the basis of endogenous oxides nuclei during the refining process,and that the number of former is 4-13 times as that of latter.And the inclusions also originate form and grow on the basis of endogenous inclusions combined with entrapped inclusions,the exogenous MgO entrapped inclusions,and include the CaSinclusions.Foe the(Mn,Fe)S inclusions nucleating and growing on the basis of endogenous oxides nuclei during the refining process,the number of them by the BOF process is about 4 times as that by the EAF process.The amount,size and aspect ratio of the former sulphide inclusions from saturated precipitation are larger than those from formation and growth on the basis of endogenous oxides nuclei during the refining process.The(Mn,Fe)S inclusions on the basis of endogenous oxide inclusions in the F40 VS by the BOF process are 4 times as those by the EAF process.Finally,some suggestions have been supplied on the control of sulphide inclusions in micro-alloyed steel as follow,decrease of oxygen content in steel,enhancement of Ca treatment at the end of the refining process to increase the amount of the sulphide as the centre of endogenous oxides,low superheat control and strengthening the M-EMS during continuous casting process to make casting microstructure fine and decrease the dendrite segregation.更多还原