On the formability of sheet steels

Formability of sheet steel in stamping operation primarily depends on strain hardening exponent (n), average plastic strain ratio ( ) and the maximum strain the material can undergo before the onset of localized necking. The formability parameters (n and ) and the forming limit diagrams have been evaluated for a variety of sheet steel products, extensively used for press forming of components of diverse shapes e.g. extra deep drawing quality auto-body sheets, high strength cold rolled sheets, LPG steel for gas cylinders, austenitic and ferritic stainless steels, etc. The effect of sulphide shape control on formability of hot rolled HSLA steel has also been studied. Additionally, the press performance of auto-body sheets and austenitic stainless steels have been monitored and evaluated at customer’s end for complete information on the formability.