Effect of Annealing Temperature and Coiling Temperature on r-value of Nb and B-added Extra Low-carbon Steel for Welded Cans

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