Microstructure based prediction and homogenization of the strain hardening behavior of dual-phase steel
Microstructure based prediction and homogenization of the strain hardening behavior of dual-phase steel
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DOI：
10.1007/s00419-014-0974-3
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发表时间：
2015-01
影响因子：
2.8
通讯作者：
F. Rieger;T. Böhlke
中科院分区：
文献类型：
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作者：
F. Rieger;T. Böhlke
采用两种不同的方法对汽车用双相钢（DP）的力学行为进行了模拟：全场代表体积元（RVE）和平均场模型。在这项工作的第一部分中，全场RVE是由一个晶体塑性为基础的铁素体基体与冯米塞斯型马氏体夹杂物。为了隔离马氏体的影响，将全场DP结果与全场比较RVE进行比较。在比较RVE中，所有马氏体夹杂物被表现出平均铁素体行为的相替代。较高的相对马氏体晶界覆盖率有利于淬火后平均位错密度的增加。然而，单轴变形超过10%，晶粒尺寸依赖关系逆转，并表现出缓慢的硬化。在第二部分中，我们将从全场模拟的主要结果到一个非线性平均场模型的Hashin-Shtrikman类型。位错密度产生参数和饱和位错密度是基于晶粒尺寸和马氏体覆盖率建模的。这两种方法的比较显示出良好的协议的整体和组成的平均行为。
The mechanical behavior of automotive dual-phase steel (DP) is modeled by two different approaches: with a full-field representative volume element (RVE) and with a mean-field model. In the first part of this work, the full-field RVE is constituted by a crystal plasticity-based ferrite matrix with von Mises-type martensite inclusions. To isolate the martensite influence, the full-field DP results were compared to a full-field comparison RVE. In the comparison RVE, all martensite inclusions were replaced by a phase that exhibits the average ferrite behavior. A higher relative martensite grain boundary coverage facilitates an increased average dislocation density after quenching. However, for uniaxial deformations above ∼10%, the grain size-dependent relation reverses and exhibits slowed-down hardening. In the second part, we incorporate the main findings from the full-field simulations into a nonlinear mean-field model of Hashin–Shtrikman type. The dislocation density production parameter and the saturated dislocation density are modeled based on grain size and martensite coverage. The comparison of both approaches shows good agreement for both the overall and constituent averaged behavior.