摘要
使用热膨胀仪等手段研究了稀土对Fe-C和Fe-C-Si-Mn低碳钢连续冷却过程奥氏体-铁素体相变温度和等温过程相变动力学的影响。结果表明,添加微量的RE元素可显著降低连续冷却过程中先共析铁素体相变的开始点温度。同时,添加微量稀土还能改变等温过程中的铁素体相变动力学:RE元素通过抑制碳扩散减缓了Fe-C-(RE)合金整个相变过程的相变速率;而对于Fe-C-Si-Mn合金,RE通过抑制C元素扩散和改变晶界能的双重作用,使其相变孕育期延长和相变初始阶段速率降低,但是提高了相变中后期的速率。
With the increasing cleanliness of steels in recent years,it has made possible for making micro-alloyed steels with rare earth elements.It is found that the addition of rare earths has a significant effect on the solid-state phase transformation behavior of steels,especially for low-carbon low-alloy steels.The effectiveness in modifying the inclusions and inducing nucleation by RE addition has been studied intensively and approved substantially.Whereas,the micro-alloying effect of RE on the ferrite phase transformation of steel is still unclear.The effect of rare earth elements(RE)on austenite-ferrite transformation temperature during continuous cooling,and the isothermal transformation kinetics of Fe-C alloys and Fe-C-Si-Mn low carbon steels has been investigated in this article.It is found that a tiny amount of RE addition can reduce the starting point temperature of proeutectoid ferrite during continuous cooling.Additionally,the addition of RE also changes the ferrite transformation kinetics in the isothermal process:for Fe-C-(RE)alloys,the addition of RE slows down the transformation rate during the whole transformation process due to the pinning carbon diffusion effect;For Fe-C-Si-Mn alloys,RE elements can play a double role of pinning carbon diffusion and changing grain boundary energy,and then prolong the incubation period and decreases the rate of phase transformation during the initial stage,while increase the phase transformation rate during the middle and late of phase transformation.
作者
郭飞
郑成武
王培
李殿中
GUO Fei;ZHENG Chengwu;WANG Pei;LI Dianzhong(Institute of Metal Research,Chinese Academy of Sciences,Shenyang National Laboratory for Materials Science,Shenyang,110016,China;School of Materials Science and Engineering,University of Science and Technology of China,Shenyang,110016,China)
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2023年第7期495-501,共7页
Chinese Journal of Materials Research
基金
国家自然科学基金(52031013)。
关键词
金属材料
相图与相变
低碳钢
奥氏体-铁素体相变动力学
稀土元素
metallic materials
phase diagram and phase transformation
low-carbon steels
austenite ferrite phase transformation kinetics
rare-earth element
