Modeling the elastic behavior of dual-phase steels is complex due to the strain dependency of Young's modulus and high elastic nonlinearity. Since it is assumed that reasons for this are to be found in microstructural behavior, microscopic in-situ analysis are necessary, but due to the overlap of the martensite and ferrite peaks, the evaluation of diffraction profiles is highly complex. Within this work, CR590Y980T (DP1000) is investigated in a continuous cyclic tensile and tension-compression test under synchrotron radiation at High Energy Material Science beamline P07 in Petra III, DESY. On basis of additional EBSD measurements, an evaluation approach is shown to analyze the dual-phase diffraction profiles in such a way that martensite and ferrite can be separated for three lattice planes. The origin of the specific elastic-plastic behavior of dual-phase steels in terms of onset of yielding, anelasticity or early re-yielding is analyzed on the basis of lattice strains and interphase stresses. For this, the time-synchronously measured micro data is correlated with the macro stress-strain relationship and thermoelastic effect. The results help to better understand strain-dependent elastic-plastic behavior of DP steels on a micro level and provide great potential to improve characterization and modeling in terms of springback prediction.

由于杨氏模量和高弹性非线性的应变依赖性，对双相钢的弹性行为进行建模很复杂。由于假定其原因在于微观结构行为，因此需要进行微观原位分析，但由于马氏体和铁素体峰的重叠，衍射曲线的评估非常复杂。在这项工作中，CR590Y980T (DP1000) 在 DESY 佩特拉 III 的高能材料科学光束线 P07 在同步辐射下的连续循环拉伸和拉伸压缩试验中进行了研究。在额外的 EBSD 测量的基础上，展示了一种评估方法来分析双相衍射轮廓，从而可以将马氏体和铁素体分离为三个晶格平面。基于晶格应变和相间应力分析了双相钢在屈服、非弹性或早期再屈服方面的特定弹塑性行为的起源。为此，时间同步测量的微观数据与宏观应力-应变关系和热弹性效应相关。结果有助于更好地理解 DP 钢在微观水平上的应变相关弹塑性行为，并为改进回弹预测方面的表征和建模提供了巨大潜力。