摘要
46MnVS钢是一种典型的中硫非调质钢,钢中硫化物的类型、大小、分布和硫偏析对其产品使用性能有重大影响。依托国内某厂的46MnVS连铸坯开展硫偏析行为及硫化物分布的研究,采用了扫描电镜、夹杂物三维腐刻等实验方法,分析了铸坯中硫化物类型、大小、分布的变化规律,总结硫偏析行为规律。研究发现铸坯中心和铸坯1/4处出现严重的正偏析,最大正偏析指数分别为1.13、1.08。计算结果表明,MnS在固相率为0.80、温度为1 425.0℃时开始从液相中析出,此时残余液相S含量为钢液初始含量的4.60倍。铸坯激冷层中硫化物的三维形貌多为不规则状;从柱状晶区边部到中心不规则状硫化物逐渐增加;中心等轴晶区从外部到中心硫化物主要为不规则状,八面体占比逐渐降低,板片状硫化物逐渐增大。
46MnVS steel is a typical medium-sulfur non-quenched and tempered steel. The type, size, and distribution of sulfide and segregation of sulfur elements in the steel have a significant impact on the performance of product. Relying on the 46MnVS continuous casting slab of a domestic factory, the sulfur segregation behavior and sulfide distribution were studied. By using scanning electron microscopy, inclusion three-dimensional etching and other test methods, the change laws of sulfide type, size and distribution in the slab were analyzed, and the sulfur segregation behavior laws were summarized. It is found that severe positive segregation occurs in the center of the slab and 1/4 of the slab, and the maximum positive segregation indexes are 1.13 and 1.08, respectively. The calculation results show MnS starts to precipitate from the liquid phase when the solid fraction of MnS is 0.80 at 1 425.0 ℃, and the residual liquid S content is 4.60 times of the initial concentration of liquid steel. The three-dimensional morphology of the sulfide in quench layer of the cast slab is mostly irregular. From the edge of columnar crystal zone to the center, the irregular sulfide increases gradually. From the outside to the center of the central equiaxed crystal region, the sulfide is mainly irregular, the proportion of octahedron decreases gradually, and the plate-like sulfide increases gradually.
作者
沈伟
李志伟
田钱仁
付建勋
SHEN Wei;LI Zhiwei;TIAN Qianren;FU Jianxun(Center for Advanced Solidification Technology(CAST),State Key Laboratory of Advanced Special Steel,Shanghai University,Shanghai 200444,China)
出处
《钢铁研究学报》
CAS
CSCD
北大核心
2023年第1期43-51,共9页
Journal of Iron and Steel Research
基金
国家自然科学基金资助项目(52074179,51874195)。
关键词
46MnVS钢
硫偏析
硫化物分布
夹杂物三维形貌
46MnVS steel
sulfur segregation
sulfide distribution
three-dimensional morphology of inclusion
作者简介
沈伟(1998-),男,硕士生,E-mail:sw980930@shu.edu.cn;通讯作者:付建勋(1969-),男,博士,教授,E-mail:fujianxun@shu.edu.cn。
