稀土对低碳高铌钢相变行为及组织的影响  

Effect of Rare Earth on Transformation Behavior and Microstructures of Low Carbon High Niobium Steel

作　　者：方琪[1,2] 李春龙[3] 勤牧 白海瑞[1,2] 董元[1,2] 孙伟[1] 

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010 [2]内蒙古自治区白云鄂博矿多金属资源综合利用重点实验室省部共建国家重点实验室,内蒙古包头014010 [3]包头钢铁(集团)公司,内蒙古包头014010

出　　处：《稀土》2015年第1期35-39,共5页Chinese Rare Earths

基　　金：国家自然科学基金项目资助(51201086);内蒙古自然科学基金项目资助(2011BS0803);内蒙古科技大学产学研合作培育基金项目资助(PY-201002)

摘　　要：利用L78 RITA热膨胀相变仪研究了不同冷速下稀土对低碳高铌钢相变行为的影响,并结合金相法绘制了加稀土和未加稀土两种成分试验钢的连续冷却相变曲线,分析了稀土对连续冷却组织的影响规律。试验结果表明,稀土加入低碳高铌钢后使连续冷却相变曲线向右移动,在相同冷速下显著降低了奥氏体向铁素体转变的开始温度,并且随着冷速的增加使降低程度增大。冷速从0.1℃/s增加到15℃/s时,加稀土的低碳高铌相变开始温度点下降了90℃,而未加稀土的下降了52℃;另一方面,稀土对低碳高铌钢在0.1℃/s到1℃/s冷速下的组织有较大影响,促进了针状铁素体的转变,并能在冷速增至5℃/s后使其更易获得板条状贝氏体组织。Effect of rare earth on transformation behavior of low carbon high niobium steel was studied by L78 RITA thermal dilatometer at various cooling rates. The continuous cooling curves for two kinds of test steels were obtained by metallography. The influence of rare earth on microstructures was also analyzed. The results show that the CCT curves shift to right,the transformation starting temperature of austenite to ferrite significantly reduces and the reducing degree enlarges with the imcrease of cooling rate by addition of rare earth. When the cooling rates increasing from 0. 1℃/s to 15℃/s,the transformation starting temperature of low carbon high niobium steel with rare earth falls 90℃,but steel without rare earth falls only 52℃. On the other hand,rare earth also has a great influence on the microstructures of low carbon high niobium steel. When cooling rates is during 0. 1℃/s to 1℃/s,the acicular ferrite transformation was promoted. Besides,the bainite ferrite was obtained easily when the cooling rates above 5℃/s.

关 键 词：稀土 低碳高铌钢 连续冷却转变曲线 相变 

分 类 号：TG142.33[一般工业技术—材料科学与工程]