Grain refinement and formation of ultrafine-grained microstructure in a low-carbon steel under electropulsing
Grain refinement and formation of ultrafine-grained microstructure in a low-carbon steel under electropulsing
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DOI：
10.1557/jmr.2002.0311
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发表时间：
2002-08
影响因子：
2.7
通讯作者：
Yi-zhou Zhou;Wei Zhang-;B. Wang;G. He;Jingdong Guo
中科院分区：
文献类型：
--
作者：
Yi-zhou Zhou;Wei Zhang-;B. Wang;G. He;Jingdong Guo
对固态低碳钢进行了大电流电脉冲处理。揭示了晶粒度与实验条件的关系。研究发现，当电流密度、加热速度和冷却速度都较高时，可以形成超细晶(UFG)组织。电脉冲法制备的UFG样品没有孔洞和污染，也没有大的微应变。此外，它们的抗拉强度比粗晶材料显著提高，而延性并没有降低。探讨了UFG组织的形成和细化机制。认为载流体系中热力学势垒的降低和成核速率的提高是不能忽略的。
High current electropulsing was applied to a low-carbon steel in the solid state. The relationship between grain size and experimental conditions was revealed. It was found that the ultrafine-grained (UFG) microstructure could be formed when electric current density, heating rate, and cooling rate all were high. The UFG samples prepared by applying electropulsing were free of porosity and contamination, and had no large microstrain. Also, their tensile strength was dramatically enhanced over that of their coarse-grained counterparts, without a decrease in ductility. The mechanism for grain refinement and formation of the UFG microstructure was discussed. It is proposed that the effect of a decrease in thermodynamic barrier and enhancement of nucleation rate in a current-carrying system cannot be neglected.