Composite Behavior of Lath Martensite Steels Induced by Plastic Strain, a New Paradigm for the Elastic-Plastic Response of Martensitic Steels
Composite Behavior of Lath Martensite Steels Induced by Plastic Strain, a New Paradigm for the Elastic-Plastic Response of Martensitic Steels
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DOI：
10.1007/s11661-016-3845-4
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
T. Ungár;S. Harjo;T. Kawasaki;Y. Tomota;G. Ribárik;Zengmin Shi
中科院分区：
文献类型：
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作者：
T. Ungár;S. Harjo;T. Kawasaki;Y. Tomota;G. Ribárik;Zengmin Shi
基于高分辨率中子衍射实验，我们将表明，在板条马氏体钢中，最初均匀的位错结构，即，在晶粒尺寸的长度尺度上是均匀的，被塑性变形破坏，这又产生了在马氏体板条包的长度尺度上的复合物。塑性应变马氏体钢的衍射图样显示出特征性的不对称峰形，其方式与在具有异质位错结构的材料中观察到的相同。通过淬火形成的准均匀板条结构被塑性变形破坏，产生复合结构。有利于或不利于位错滑移的板条束变软或变硬。两个板条束类型的发展，其中的位错密度变得更小或更大相比，初始的平均位错密度的加工软化或加工硬化。分解成软，硬板条包是伴随着负载重新分配和两个板条包类型之间的长程内应力的形成。板条马氏体塑性变形的复合行为为理解这类材料的弹塑性响应开辟了一条新途径。
Based on high-resolution neutron diffraction experiments, we will show that in lath martensite steels, the initially homogeneous dislocation structure,i.e., homogeneous on the length scale of grain size, is disrupted by plastic deformation, which, in turn, produces a composite on the length scale of martensite lath packets. The diffraction patterns of plastically strained martensitic steel reveal characteristically asymmetric peak profiles in the same way as has been observed in materials with heterogeneous dislocation structures. The quasi homogeneous lath structure, formed by quenching, is disrupted by plastic deformation producing a composite structure. Lath packets oriented favorably or unfavorably for dislocation glide become soft or hard. Two lath packet types develop by work softening or work hardening in which the dislocation densities become smaller or larger compared to the initial average dislocation density. The decomposition into soft and hard lath packets is accompanied by load redistribution and the formation of long-range internal stresses between the two lath packet types. The composite behavior of plastically deformed lath martensite opens a new way to understand the elastic-plastic response in this class of materials.