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Development of new deep drawing steels by doping with surface active elements
Author(s) -
Beyer Gerhard H.,
Grabke Hans Jürgen
Publication year - 1999
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.199905665
Subject(s) - materials science , recrystallization (geology) , metallurgy , annealing (glass) , doping , ultimate tensile strength , vacuum induction melting , microstructure , paleontology , optoelectronics , biology
In this study, the effects of doping with the surface‐active elements Ge, Te, Se, As, Sb and Sn in atomic mass contents of 10 to 200 ppm on the texture and drawability of an IF‐steel (FeP06, DIN‐EN 10130) and an ELC‐steel (FeP05, DIN‐EN 10130) were investigated. Twenty‐six ingots were produced by melting and doping in a vacuum‐induction furnace, followed by forging, hot‐rolling and cold‐rolling. The cold‐rolling reduction was ɛ = 72 %. Recrystallization annealing was performed in a batch‐annealing simulation furnace. Subsequently, the orientation distribution function (ODF) and the α, γ, η‐fibre textures of both the cold‐rolled and recrystallized state were measured by means of an X‐ray diffraction goniometer and compared with the undoped reference material. The results indicate that the IF‐steel specimens doped with 100 ppm Te and Se show a significantly enhanced γ‐fibre {111}<110>‐{111}<112> texture compared to the reference specimen. Also the ELC‐steel specimens showed a higher γ‐fibre by doping with atomic mass contents of 10 to 100 ppm Se and Te. To investigate whether the drawability has been improved, Lankford‐value ( r m and Δ r ) measurements by means of tensile tests were applied. The compositions with improved γ‐fibre also showed higher r ‐values and therefore confirmed the results of the texture measurements. Se doping was found to be especially beneficial in texture and drawability for both investigated materials. The growth of selenides and tellurides at the surface of Ti 4 C 2 S 2 ‐ and Ti 2 S‐ precipitates was observed by means of scanning transmission electron microscope linescans equipped with field emission gun (STEM‐FEG). Doping with Sb and Sn rendered no notable improvement of the materials, and Ge and As proved to affect the mechanical properties unfavourably.