“Thermomechanical processing necessary to produce DP 980 steel using CASTRIP hot band was investigated. The resultant steel has an ultimate tensile strength of 1038 MPa, yield strength of 744 MPa, and total elongation of 8.6%. These mechanical properties were achieved by batch annealing the hot band at 649°C for 48 hours and cold rolling to a 20% reduction. The steel was continuously annealed to simulate a galvanization cycle with an intercritical temperature of 810°C. The possibility of improving the texture of the steel by warm rolling under dynamic strain aging conditions was investigated. Dynamic strain aging in the CASTRIP hot band was found to have an onset activation energy of 82 kJ/mol. This indicates that dynamic strain aging is controlled by carbon diffusion in ferrite. Vickers hardness and differential scanning calorimetry tests prove that warm rolling at reductions of 20% generates a higher concentration of defects than ambient temperature cold rolling. Recrystallization was not obtained during warm rolling or during the continuous annealing heat treatment. Tensile tests and x-ray diffraction results show that warm rolling in dynamic strain aging conditions does not significantly improve the texture of the steel, which remains an essentially randomly oriented texture”--Abstract, page iii.
Van Aken, David C.
O'Malley, Ronald J.
Moats, Michael S.
Materials Science and Engineering
M.S. in Metallurgical Engineering
Missouri University of Science and Technology
x, 90 pages
© 2019 Brenton Allen Hrebec, All rights reserved.
Thesis - Open Access
Electronic OCLC #
Hrebec, Brenton Allen, "Development of CASTRIP dual phase steel" (2019). Masters Theses. 8046.