Effect of stretching angle on internal defects in valve roughcasts produced by single cross wedge rolling

The forming process of valve roughcasts by single cross wedge rolling was simulated with finite element software DEFORM-3D 6.0,focusing on the stress and strain fields and alternating times of rolled pieces at the center point under different stretching angles.Rolling experiments at different stretching angles were done on an H500 rolling mill,and the area of the centre hole was calculated for each rolled piece.The influence of stretching angle on internal defects in rolled pieces was analyzed on the basis of simulation and experimental results.It is shown that a relatively larger stretching angle can improve the internal defects.Experimental results show that the area of the centre hole decreases with the stretching angle increasing.The stretching angle of 8°40' is propitious to improve internal defects in valve roughcasts produced single cross wedge rolling when the other parameters are invariable.