锆脱氧钢中非金属夹杂物及对显微组织的影响  

Non-metallic Inclusions and Its Effect on Microstructure of Zr Deoxidized Steel

作　　者：王超[1] 王国栋[1] 

机构地区：[1]东北大学轧制技术及连轧自动化国家重点实验室,辽宁沈阳110819

出　　处：《东北大学学报（自然科学版）》2015年第5期641-645,共5页Journal of Northeastern University(Natural Science)

基　　金："十二五"国家科技支撑计划项目(2012BAF04B01)

摘　　要：实验用钢在低碳锰钢基础上采用锆脱氧及钛微合金化,研究了连续冷却和等温热处理条件下的组织转变行为,分析了夹杂物的析出类型及对组织转变的影响机理.统计结果表明：夹杂物在0.2~1μm尺寸范围内有较高的数量密度,主要为Zr O2·Mn S和Zr O2·Mn S·Ti N复相夹杂,与热力学分析结果一致.实验钢以1℃/s连续冷却及500℃等温时均得到晶内针状铁素体组织,促进铁素体形核的主要夹杂物类型为Zr O2·Mn S·Ti N.Mn S以Zr O2为核心复合析出形成贫锰区是促进铁素体形核的重要因素,Ti N的复合析出降低了铁素体形核界面能,进一步促进了针状铁素体转变.Transformation behaviors of a Zr deoxidized and Ti microalloyed low C-Mn steel under continuous cooling and isothermal treatment were studied. The precipitation of non-metallic inclusions and its influence on the microstructure were analyzed. Statistical results showed that the inclusions are mainly ZrO2· MnS and ZrO2· MnS. TiN composites, which are in accordance with thermodynamic analysis. The size of inclusions is in the range of 0. 2 - 1μm and the number density of inclusions is high. Intragranular acicular ferrite is obtained under both conditions of continuous cooling with 1 ℃/s and isothermal treatment at 500 ℃. Inclusions, which can promote ferrite nucleation, are mostly ZrO2 · MnS. TiN type. Formation of Mn-depletion zone with MnS precipitation on the ZrO2 core is an important factor in ferrite nucleation. Composite precipitation of TiN can reduce the interface energy of ferrite nucleation, which can further promote acicular ferrite transformation.

关 键 词：锆脱氧钢 非金属夹杂物 针状铁素体 贫锰区 ZRO2 

分 类 号：TG142.1[一般工业技术—材料科学与工程]