超薄铁素体不锈钢电处理辅助多步成形工艺研究  

Multi-Step Forming with Intermediate Electrical Treatment of Ultra-thin Ferritic Stainless Steel Sheet

作　　者：谭劲军 张翔鹭 闵峻英[1] TAN Jinjun;ZHANG Xianglu;MIN Junying(School of Mechanical Engineering,Tongji University,Shanghai 201804,China)

机构地区：[1]同济大学机械与能源工程学院,上海201804

出　　处：《精密成形工程》2025年第4期70-77,共8页Journal of Netshape Forming Engineering

基　　金：国家重点研发计划(2020YFB1505900);小米青年学者项目。

摘　　要：目的针对超薄铁素体不锈钢(厚度为0.1 mm)在常温下成形极限低的问题,提出一种电处理辅助的多步成形工艺,并研究电处理参数对超薄铁素体不锈钢成形性能的影响。方法进行电处理辅助多步单向拉伸实验,调节电处理时间(2~8 s)和功率(0~10.5 kW),分析电处理时间及处理温度对超薄铁素体不锈钢加工硬化指数和延伸率的影响。基于拉伸实验确定的电处理参数,进行电处理辅助的多步冲压成形实验,验证新工艺对超薄铁素体不锈钢双极板的极限成形深度和厚度均匀性的提升效果。结果与未经电处理的超薄铁素体不锈钢相比,经1000℃电处理后试样的加工硬化指数由0.013提升至0.069,总延伸率由0.203增加至0.305。在冲压成形实验中,与未经电处理的双极板相比,经1000℃电处理的双极板流道极限成形深度由250μm提升至325μm,且成形后双极板的厚度均匀性显著改善。结论电处理辅助多步成形工艺显著提升了超薄铁素体不锈钢的成形性能,增强了其加工硬化能力并提高了总延伸率,从而改善了双极板的极限成形深度和厚度均匀性。该工艺克服了传统常温冲压工艺中易开裂的问题,为超薄铁素体不锈钢在质子交换膜燃料电池双极板中的应用提供了新的解决方案,具有广阔的应用前景。The work aims to propose a novel electrically assisted multi-step forming method to improve the forming limits of ultra-thin ferritic stainless steel(FSS)with a thickness of 0.1 mm,and study the effect of electropulsing treatment parameters on the formability of ultra-thin ferritic stainless steel.Specifically,the effects of EPT duration and the resulting sample temperature on the work hardening coefficient and total elongation of FSS were evaluated through electrically assisted multi-step tensile tests,with the EPT duration varied from 2 to 8 s and the electric power from 0 to 10.5 kW.Based on the electric processing parameters determined by the tensile tests,an EPT-assisted multi-step forming experiment was carried out to verify the effect of the new process on the ultimate forming depth and thickness uniformity of ultra-thin ferritic stainless steel bipolar plates(BPPs).The results demonstrated that by applying an intermediate EPT,which achieved a maximum temperature of 1000℃,the work hardening coefficient of prestrained FSS increased from 0.013 to 0.069,and the total elongation improved from 0.203 to 0.305.Furthermore,stamping tests confirmed that the maximum achievable channel depth of the BPPs was enhanced from 250μm to 325μm,while simultaneously improving their thickness uniformity.Overall,the EPT-assisted multi-step forming process enhances the work hardening ability and total elongation of FSS,thus increasing the channel depth and improving the thickness uniformity of FSS BPPs.The process overcomes the problem of easy cracking in the traditional normal temperature stamping process,and provides a new solution for the application of ultra-thin ferritic stainless steel in proton exchange membrane fuel cell bipolar plates,and has broad prospects of application.

关 键 词：超薄铁素体不锈钢 多步冲压 电处理 双极板 精密成形 

分 类 号：TG156.7[金属学及工艺—热处理]