Predictive of die wear during trimming of high strength steel automotive parts

点击翻译按钮获取中文摘要

The severe die wear that results from trimming advanced high-strength steel (AHSS) automotive parts is significantly increasing production costs. Indeed, damage of the trim edges deteriorates the quality of the sheared edges of stamped parts with potential for splitting in subsequent operations, and requires more frequent die maintenance. The broad objective of this research is to develop a methodology to determine the micro-mechanisms of wear, and then predict the evolution of wear in automotive trim dies. In collaboration with Ford of Canada, the University of Windsor will first determine the type of wear that occurs at the edges of trim dies. Using Ford's semi-production trimming facility, coils of DP980 steel will be continuously trimmed up to large numbers of cycles so as to produce worn trim dies under specific trimming conditions. The edge of worn trim dies will be meticulously analyzed using state-of-the-art microscopy, spectroscopy and profilometry techniques in order to understand the wear micro-mechanisms and how they evolve with repeated trimming cycles. An instrumented laboratory-scale trimming press will also be constructed at the University of Windsor with in-situ observation capability to investigate the evolution of microstructural features of die inserts during trimming tests. Finally, numerical tools will be developed that are able to model the accumulation of microstructural damage and predict die wear and the consequent dulling of the trim edges. In this research, 3 graduate students and 1 post-doctoral fellow will be trained to evaluate, analyze and understand the micro-mechanisms of wear, adhesion, micro-cracking and chipping near the edge of trim dies. Furthermore, the PhD student will develop predictive tools that will enable Ford process engineers to evaluate the durability of various combinations of die materials/coatings and AHSS sheet materials. This will not only facilitate the selection of more durable tool materials/coatings, but it will also help to reduce maintenance costs associated with stamping AHSS parts, which help to reduce vehicle weight and fuel consumption.