微量稀土Ce对DX51D+Z低碳钢连续冷却转变曲线的影响  

Effect of trace rare earth Ce on continuous cooling transformation curve of DX51D+Z low carbon steel

作　　者：杨维宇[1,2] 魏晓东 白雅琼 张晓峰[1,2] 郎荣彪 Yang Weiyu;Wei Xiaodong;Bai Yaqiong;Zhang Xiaofeng;Lang Rongbiao(Technical Center,Inner Mongolia Baotou Steel Union Co.,Ltd.,Baotou Inner Mongolia 014010,China;Key Laboratory of Rare Earth Steel Products Research and Development,Baotou Inner Mongolia 014010,China)

机构地区：[1]内蒙古包钢钢联股份有限公司技术中心,内蒙古包头014010 [2]内蒙古自治区稀土钢产品研发重点实验室,内蒙古包头014010

出　　处：《金属热处理》2024年第10期234-238,共5页Heat Treatment of Metals

摘　　要：利用Formaster-F型全自动相变仪,结合显微组织分析,绘制了添加和未添加稀土元素Ce的DX51D+Z低碳钢的连续冷却相变曲线,研究了不同冷速下稀土对DX51D+Z钢连续冷却相变点和显微组织的影响。结果表明,微量稀土Ce(9×10^(-6))的添加,使DX51D+Z钢的Ac_(1)相变点温度降低3℃,Ac_(3)相变点温度升高9℃,增大了缓慢加热过程中α-Fe→γ-Fe相变区间;当冷却速度为0.05~2℃/s时,微量稀土Ce对试验钢的相变开始和终止温度影响不大;当冷速≥5℃/s时,微量稀土Ce使试验钢的相变终止温度降低,扩大了铁素体+珠光体、铁素体+贝氏体的相变区间,使静态CCT曲线向左下方移动;在0.1~20℃/s冷速范围内,含稀土Ce的试验钢铁素体晶粒度比不含稀土的高0.2~0.4级,且晶粒尺寸分布更均匀。Continuous cooling phase transformation curves of the DX51D+Z low carbon steel with and without rare earth element Ce were drawn by Formaster-F automatic phase transformation instrument combined with microstructure analysis.The effects of rare earth on the continuous cooling phase transformation points and microstructure of the DX51D+Z steel at different cooling rates were studied.The results show that the addition of trace rare earth Ce(9×10^(-6))reduces the Ac_(1) transformation point temperature of the DX51D+Z steel by 3℃and increases the Ac_(3) transformation point temperature by 9,increasing the phase transformation interval fromα-Fe→γ-Fe during slow heating.When the cooling rate is 0.05-2℃/s,the trace rare earth Ce has litle effect on the the starting and ending temperature of phase transformation of the tested steel.When the cooling rate is greater than 5℃/s,the trace rare earth Ce reduces the phase transformation termination temperature,expands the phase transformation range of ferrite+pearlite and ferrite+bainite,and shifts the static CCT curve to the lower left.Within the cooling rate range of 0.1-20℃/s,the grain size grade of the tested steel with rare earth Ce is 0.2-0.4 higher than that without rare earth,and the grain size distribution is more uniform.

关 键 词：稀土Ce DX51D+Z低碳钢 CCT曲线 微观组织 

分 类 号：TG142.1[一般工业技术—材料科学与工程]