Effect of Heat Treatment on Microstructures and Tensile Properties of Ultrafine Grained C-Mn Steel Containing 0.34 mass% V
Effect of Heat Treatment on Microstructures and Tensile Properties of Ultrafine Grained C-Mn Steel Containing 0.34 mass% V
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DOI：
10.2355/isijinternational.44.1057
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发表时间：
2004-06
影响因子：
1.8
通讯作者：
Kyung-Tae Park;S. Han;D. Shin;Young‐kook Lee;K. Lee;K. Lee
中科院分区：
文献类型：
--
作者：
Kyung-Tae Park;S. Han;D. Shin;Young‐kook Lee;K. Lee;K. Lee
采用等通道转角挤压（ECAP）工艺制备了一种含较高钒量的超细晶C-Mn钢，并对其显微组织和拉伸性能进行了研究。研究了材料加工过程中钒析出相的析出阶段对超细晶C-Mn钢拉伸性能，特别是强度和应变硬化性能的影响。为此目的，对本钢进行两种不同的热处理：（a）在ECAP之前进行常规正火以使钒沉淀，和（B）在ECAP期间进行等温转变以使钒沉淀和随后的退火。结果表明，第二次热处理可使纳米级钒析出相均匀分布，并与超细铁素体晶粒内的晶格位错发生广泛的相互作用，从而更有效地提高钢的热稳定性和整体拉伸性能。此外，通过对二次热处理后的钢与不含钒的超细晶C-Mn钢的显微组织和应力-应变曲线的比较，探讨了提高超细晶C-Mn钢应变硬化能力的可行性。
An ultrafine grained (UFG) C-Mn steel containing a relatively large amount of vanadium was fabricated by equal channel angular pressing (ECAP) and its microstructures and tensile properties were examined. This investigation was aimed at demonstrating the effect of precipitation stage of vanadium precipitates in the course of the material processing on the tensile properties of the ultrafine grained C-Mn steel, especially strength and strain hardening capability. For this purpose, the two different heat treatments were carried out on the present steel: (a) conventional normalization for vanadium precipitation before ECAP, and (b) isothermal transformation for vanadium precipitation during ECAP and subsequent annealing. The results showed that the second heat treatment was more effective on improving the thermal stability and the overall tensile properties of the steel by better uniform distribution of nano-sized vanadium precipitates which yielded an extensive interaction with lattice dislocations inside ultrafine ferrite grains. In addition, in this report, the feasibility enhancing the strain hardening capability of the UFG C-Mn steel was explored by comparing the microstructure and stress-strain curve of the steel prepared by the second heat treatment with those of the UFG C-Mn steel without vanadium.