柔性薄膜太阳能电池用精密不锈钢基板冷轧成形的数值模拟

Simulation of Cold Rolling Process of Stainless Steel Strip Used as Flexible Thin Film Solar Cell Substrate

利用有限元方法,研究了压下量及前后张力对柔性薄膜太阳能电池用不锈钢基板轧制过程中应力分布的影响。结果显示,适当增加压下量有利于表面应力的均匀分布,且可减少轧制道次,但过大压下量容易导致不均匀塑性变形;采用后张力稍大于前张力的轧制工艺,可使基板应力分布趋向均匀,当前后张力值分别为40 kN和58 kN时,应力分布均匀且板内最大等效应力值最小。研究表明,采用后张力稍大于前张力、压下率控制在30%以内的轧制工艺,可保证薄板应力值较小且分布均匀。最后,在模拟结果的指导下,成功轧制得到厚0.25 mm的不锈钢基板,其厚度分布与模拟结果基本一致,且粗糙度满足基板的使用要求。

This paper uses the finite element methodl （FEM）to investigate the influence of rolling reduction and tension on stress distributed along stainless steel strip for flexible thin film solar cell substrate during cold rolling process. The result shows that proper increase in rolling reduction can lead to uniform distribution of stress and minimize rolling passes, but the oversize results in uneven plastic deformation. The higher back than front tensile force method can be used to uniformize the distribution of stress along the srip. When the fronVback tension is 40 kN/58 kN, the rolled strip facial stress is well-distributed and the peak value turns back to the lowest value. The results indicate that the stress along the stainless steel strip, which is rolled under 30% reduction rate using higher back tension force is ensured to be appropriate and uniform. Afterwards, the stainless steel strip with the thickness 0.25 mm is successfully formed under the direction of FEM results. This thickness is accordance with the simulation results and its roughness meets the substrate demands.