Abstract Cementite dissolution behavior of pearlitic steels subjected to rolling-sliding contact deformation is comprehensively investigated by combining experimental characterization and phase-field modeling. An elasto-plastic phase-field model, incorporating the elastic strain-induced free energy contribution from first-principles calculations and the plastic counterpart from a rolling-sliding contact finite element model assisted with a plastic strain accumulation model, is originally proposed to simulate the real-time evolution of cementite volume fraction, cementite morphology and carbon distribution for different rolling cycles and contact depths. Upon experimental validations, the proposed model predicts more accurate and realistic results than Sauvage’s model. A three-stage behavior of cementite dissolution is also revealed, which well explains an experimentally observed significant cementite dissolution gradient along the depth direction. Besides, the effect of ferrite/cementite interface thickness and the initial lamellae thickness of cementite on cementite dissolution kinetics is studied. The proposed phase-field model can not only help understand the mechanism of cementite dissolution, but also give new sights into quantitative predictions of the mechanical properties and even the rolling contact fatigue life of pearlitic rail steels in service.

中文翻译：

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了解珠光体钢在滚动-滑动接触载荷下的渗碳体溶解：结合实验和理论研究

摘要 结合实验表征和相场模拟，综合研究了珠光体钢在滚滑接触变形下的渗碳体溶解行为。弹塑性相场模型，结合了第一性原理计算的弹性应变引起的自由能贡献和塑性应变累积模型辅助的滚动-滑动接触有限元模型的塑性对应物，最初被提出来模拟不同轧制周期和接触深度下渗碳体体积分数、渗碳体形态和碳分布的实时演变。经过实验验证，所提出的模型比 Sauvage 的模型预测的结果更准确、更真实。还揭示了渗碳体溶解的三阶段行为，这很好地解释了实验观察到的沿深度方向显着的渗碳体溶解梯度。此外，研究了铁素体/渗碳体界面厚度和渗碳体初始片层厚度对渗碳体溶解动力学的影响。所提出的相场模型不仅有助于理解渗碳体溶解的机制，而且为定量预测珠光体钢轨钢的力学性能甚至滚动接触疲劳寿命提供了新的视角。