Effect of annealing temperature and coiling temperature on r-value of nb and b-added extra low-carbon steel

Abstract

When a welded can body is expanded in the pail can manufacturing process, it shrinks in the direction of can height. The change of the can height is influenced by the r-value of the steel sheet. The effect of the annealing temperature and coiling temperature on the r-value of extra low-carbon steel with combined addition of niobium (Nb) and boron (B) was investigated by using commercial steels. The ferrite grain size of the annealed sheet decreased as the annealing temperature decreased. At the same time, the orientation density of (001) <110> increased and the r90°-value decreased. The behavior of the decrease of the r90°-value was dependent on the coiling temperature of the hot-rolled sheet. When a low coiling temperature was used, the r90°-value decreased rapidly as the annealing temperature decreased.