摘要
大型夹杂物对钢材的加工性能、力学性能和耐腐蚀性能等产生十分有害的影响。用电解萃取法研究了钙处理钢中大型球状/棒状夹杂物的性质,通过对大型球状/棒状夹杂物形貌的扫描电镜观察和元素成分能谱分析,指出钢中的大型球状/棒状夹杂起源于呈团簇状的铝脱氧产物Al2O3。大量小颗粒Al2O3夹杂组成尺寸较大的夹杂团簇,在钢包内复杂流场作用下形成球状或棒状。钢液在钙处理过程中,变性充分的夹杂物形成了低熔点的铝酸钙,在钢液凝固后形成致密的球状夹杂物;变性不充分的夹杂外形仍然保留Al2O3夹杂颗粒形貌。钙处理使Al2O3夹杂变性所需的w([Ca])/w([Al])主要受钢液中硫质量分数影响。铝酸钙对钢液中的硫有较强的吸收溶解能力,在浇铸过程中,随着钢液温度下降,铝酸钙吸收的硫以CaS夹杂形式从基体中饱和析出。
Large inclusions have a very harmful effect on the processing properties,mechanical properties and corrosion resistance of steel.The properties of large spherical or bar-shaped inclusions,which were obtained by electrolytic extraction method in calcium treated steel,were investigated.The results of both the scanning electron microscopy(SEM)and elemental composition analysis indicated that the large spherical or bar-shaped inclusions were originated from the clustered aluminum de-oxidation product,such as Al2O3.A large number of small Al2O3 particles had the tendency to form large-sized inclusion clusters,which further form a spherical or bar-shaped by the complex flow field in the ladle.During the calcium treatment process,the modified inclusions can form a low melting calcium aluminate,which can form dense spherical shaped inclusions during the solidification process of molten steel;the shape of the inclusions with insufficient modified was still kept the same morphology as Al2O3 inclusion.The w([Ca])/w([Al])ratio required for calcium treatment to modify Al2O3 inclusions is primarily affected by the content of S.The calcium aluminate has a strong absorption and dissolution ability to S in molten steel.During the casting process,as the temperature of molten steel decreasing,the S element absorbed by the calcium aluminate was precipitated from the matrix in the form of CaS inclusions.
作者
秦正丰
薛正良
李金波
李博思
QIN Zheng-feng;XUE Zheng-liang;LI Jin-bo;LI Bo-si(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China;Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan 430081,Hubei,China;Hansteel Co.,HBIS Group,Handan 056015,Hebei,China)
出处
《钢铁》
CAS
CSCD
北大核心
2020年第5期31-38,共8页
Iron and Steel
基金
国家自然科学基金资助项目(51874214)。
关键词
大型球状/棒状夹杂
簇状Al2O3
夹杂物电解萃取
钙处理
large spherical or bar-shaped inclusions
alumina cluster
electrolytic extraction of inclusions
calcium treatment
