Experimental analysis of the hot formability of usibor 1500 steel sheets with reduced thickness

Abstract

It was learnt in the first phase of the Undergraduate Research Project (September 2012 to August 2013) how boron hardenable steels DIN 22MnB5 and DIN 27MnCrB5 are influenced by heating temperature and cooling rate during hot, warm, cold and aus stamping. Such processes are very advantageous for many industries due to improve mechanical properties, and to reduce costs and raw material. In the automotive industry, these processes provide reduction of weight, increase of absorption in eventual impacts or collisions, decrease of fuel consumption and safety improvement. Currently, there are few studies on warm stamping, especially with boron steels. The increase of material toughness was the first goal of the project. The metallographic analyses done in the first phase were extremely important to confirm the improvement of mechanical properties, mainly because of the ferrite-perlite to martensite phase transformation from the raw material to the stamped part. The activities were held at the Laboratory of Metal Forming, School of Mechanical Engineering, University of Campinas (UNICAMP). The main objective of this research abroad is to study the hot formability of a high strength steel, at the Laboratory of Precision Manufacturing Engineering, Department of Industrial Engineering, University of Padova, Italy, within an abroad internship program funded by FAPESP. Prof. Stefania Bruschi will be the supervisor abroad. She is proposing an industrial project in collaboration with an automotive company to support this research. Nakajima tests will be carried out at different temperatures and strain rates, in order to determine the material hot formability limits. The sheet metal object of the investigation will be the Usibor 1500 steel, provided in sheets thinner than the conventional ones, with the aim of evaluating the reduction of formability due to the thickness reduction. This research will contribute to improve the abilities and skills of the student in the second phase of his Undergraduate Research (September 2013 to August 2014), as well as in his first experience abroad. (AU)