Microstructure and crystallographic texture of an ultrafine grained C-Mn steel and their evolution during warm deformation and annealing
Microstructure and crystallographic texture of an ultrafine grained C-Mn steel and their evolution during warm deformation and annealing
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DOI：
10.1016/j.actamat.2004.10.051
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发表时间：
2005-02
期刊：
影响因子：
9.4
通讯作者：
R. Song;D. Ponge;D. Raabe;R. Kašpar
中科院分区：
文献类型：
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作者：
R. Song;D. Ponge;D. Raabe;R. Kašpar
研究了0.2%C-Mn钢在大应变温变形及随后退火过程中的组织和织构演变。温变形过程中的晶粒细化过程是形成超细晶粒的关键。研究表明，显着的回复，而不是一次再结晶，需要获得大部分的大角度晶界（HAGB）作为一个先决条件，在温变形过程中的超细晶粒的发展。在这种情况下，一次再结晶而不是回复的流行通常不是有益的，因为它显著降低了位错密度，并消除了亚结构，这对于亚晶粒的逐渐形成以及最终被HAGB包围的超细晶粒的形成是重要的。超细晶0.2%C-Mn钢经大应变温变形和退火后的织构主要由α-（α 110 α RD）织构纤维组成，具有较强的回复性。再结晶铁素体钢中的γ-（α 111 α ND）织构纤维没有出现。因此，在变形和随后的退火期间发生的过程可以被解释为明显的恢复过程，在该过程中，在没有先前的成核的情况下产生新的晶粒。
The evolution of microstructure and texture of a 0.2%C–Mn steel during large strain warm deformation and subsequent annealing has been investigated. The process of grain subdivision during warm deformation is essential for the formation of ultrafine grains in such a material. The study reveals that pronounced recovery instead of primary recrystallization is required to obtain a large fraction of high-angle grain boundaries (HAGBs) as a prerequisite for the development of ultrafine grains in the course of warm deformation. The prevalence of primary recrystallization instead of recovery is not generally beneficial in this context since it reduces significantly the dislocation density and removes the substructure which is important for the gradual formation of subgrains and, finally, of ultrafine grains which are surrounded by HAGBs. Consistently, the texture of the ultrafine grained 0.2%C–Mn steel observed after large strain warm deformation and subsequent annealing, consists primarily of the α-(〈110〉∥RD) texture fiber which indicates strong recovery. The γ-(〈111〉∥ND) texture fiber which is typical of recrystallized rolled ferritic steels does not appear. The process occurring during the deformation and subsequent annealing can, therefore, be interpreted as a pronounced recovery process during which new grains are created without preceding nucleation.