화학공학소재연구정보센터
Materials Science Forum, Vol.426-4, 1445-1450, 2003
Cold plasma discharge processes: An alternative technology for steel annealing
This paper presents the general features of a new heating process developed by the authors in order to conduct steel annealing in a potentially more economical and more efficient fashion than conventional technologies. This process consists of generating a cold plasma discharge in argon in the vicinity of the steel surface. The discharge is generated between the steel surface, cathode of the system, and the anode facing it. The steel heating results from the bombardment of its surface by energetic neutrals and ions. Conventional low carbon steel annealing cycles have been reproduced at laboratory scale with this new annealing technology and led to equivalent metallurgical properties. Moreover this new plasma annealing technology allowed the opportunity for new annealing cycles with higher heating rate (up to several hundreds of K/s), shorter soaking time and controlled cooling rate, so that well recrystallized samples were achieved in a few seconds total process time. Experimental evidence shows that process parameters such as the heating and cooling rates, the maximum annealing temperature and the soaking time strongly influence the recrystallization process and the metallurgical texture development, hence the steel mechanical properties. In conclusion, this paper indicates clearly that, at least for low carbon steel annealing, thanks to this new plasma annealing technology, the total annealing time can be significantly reduced compared to the time required by the industrial continuous annealing process used today to obtain equivalent metallurgical properties.