Experimental and numerical investigations on the description of cold formability of extra abrasion-resistant steel considering surface roughness effects were performed in this study. A novel multiscale numerical approach to quantitatively evaluate the impacts of surface roughness on the cold formability/bendability of heavy plates was proposed and verified. The macroscopic ductile damage behavior of the investigated steel was described by a hybrid damage mechanics model, whose parameters were calibrated by notched round-bar (NRB) tensile tests and single-edge notched bending (SENB) tests. The surface roughness was characterized by confocal microscopy and statistically incorporated into a two-dimensional representative volume element (RVE) model. For the assessment of the bendability of heavy plates in the component level, the critical ratio between the punch radius and the sample thickness r/t in three-point bending tests was predicted and compared with experimental results. After the surface roughness effects were taken into consideration, a significant improvement in the predicted results was achieved. A good match between the simulation and experimental results confirmed the indispensable influences of surface roughness on the bendability of steels and validated the efficiency of the multiscale simulation approach in the quantitative description of surface roughness affected ductile damage evolutions.

在这项研究中，考虑了表面粗糙度的影响，对描述超耐磨钢的冷成形性能进行了实验和数值研究。提出并验证了一种新颖的多尺度数值方法，用于定量评估表面粗糙度对厚板的冷成形性/弯曲性的影响。用混合损伤力学模型描述了被调查钢的宏观延性损伤行为，该模型的参数通过缺口圆杆（NRB）拉伸试验和单边缺口弯曲（SENB）试验进行了校准。通过共聚焦显微镜对表面粗糙度进行表征，并将其统计合并到二维代表性体积元素（RVE）模型中。为了评估重型平板在组件级别的可弯曲性，预测了三点弯曲试验中的r / t并与实验结果进行了比较。在考虑了表面粗糙度的影响后，预测结果得到了显着改善。模拟与实验结果的良好匹配证实了表面粗糙度对钢的可弯曲性必不可少的影响，并验证了多尺度模拟方法在定量描述表面粗糙度影响韧性破坏演变方面的效率。