Drawability of Nickel Siver Sheet

Abstract

Drawability of metal sheets is known to be determined mainly by the factors such as preferred orientation and grain size. These factors affect differently to various metal sheets. In mild steel sheets the preferred orientation is the dominant factor for improvement of drawability and texture control provides the posibilities of improving drawing performance. On the other hand, in 18-8 stainless steel and 70-30 brass sheets the drawability is rather insensitive to the crystallographic texture and the useful improvement in drawing performance is accomplished by the control of grain size.
In nickel-silver sheets the contribution of these factors is not clear. The authors have studied the drawability of nickel-silver sheets in terms of the preferred orientation and grain size, and obtained the following results:
(1) With increase in reduction of cold rolling, the component orientated in (225)[73\bar4] develops in the annealing texture and the r-value in the direction 45° apart from the rolling direction becomes high. But conical cup value does not vary correspondingly with the r-value, so the drawability of nickel-silver sheets is insensitive to the crystallographic texture.
(2) The drawability of nickel-silver sheets is well correlated to the grain size, and the coarse grain sheet is favourable for drawing performance.