Grain size effect on high-speed deformation of Hadfield steel
Grain size effect on high-speed deformation of Hadfield steel
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DOI：
10.1007/s10853-012-6604-y
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发表时间：
2012-06
影响因子：
4.5
通讯作者：
R. Ueji;D. Kondo;Y. Takagi;T. Mizuguchi;Yasuhiro Tanaka;K. Shinagawa
中科院分区：
文献类型：
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作者：
R. Ueji;D. Kondo;Y. Takagi;T. Mizuguchi;Yasuhiro Tanaka;K. Shinagawa
研究了微观组织对Hadfield钢在高应变速率下拉伸性能和断裂行为的影响。通过中温轧制和随后的退火制备具有不同平均晶粒尺寸和碳相的哈德菲尔德钢样品。平均晶粒尺寸大于10μm且含有少量碳化物的样品在103s−1的高速拉伸变形速率下表现出具有局部伸长（均匀伸长后）的延展性。此外，随着应变率的增加，断裂表面从脆性变为延性。相比之下，含有碳化物的细晶粒样品在任何应变速率下都会发生脆性断裂。通过考虑动态应变时效以及裂纹产生的位错发射来讨论晶粒尺寸依赖性。晶粒细化导致的碳加速扩散被认为是细晶哈德菲尔德钢脆性断裂的重要原因之一。
The influence of the microstructure on the tensile properties and fracture behavior of Hadfield steel at high strain rate were studied. Hadfield steel samples with different mean grain sizes and carbon phases were prepared by rolling at medium temperatures and subsequent annealing. A sample with an average grain size larger than 10 μm, and a small number of carbides shows ductility with local elongation (post uniform elongation) at a high-speed tensile deformation rate of 103s−1. In addition, the fracture surface changes from brittle to ductile with increasing strain rate. In contrast, a fine-grained sample with carbides undergoes brittle fracture at any strain rate. The grain size dependence is discussed by considering the dynamic strain aging as well as the emission of dislocation from cracks. The accelerated diffusion of carbon due to grain refinement is considered as one of the important reason for brittle fracture in the fine-grained Hadfield steel.