The Lankford coefficient (also called Lankford value, R-value, or plastic strain ratio) is a measure of the plastic anisotropy of a rolled sheet metal. This scalar quantity is used extensively as an indicator of the formability of recrystallized low-carbon steel sheets.
Contents
Definition
If
where
More recent studies have shown that the R-value of a material can depend strongly on the strain even at small strains . In practice, the
For sheet metals, the
The planar anisotropy coefficient or planar R-value is a measure of the variation of
Anisotropy of steel sheets
Generally, the Lankford value of cold rolled steel sheet acting for deep-drawability shows heavy orientation, and such deep-drawability is characterized by
In an ordinary cold rolled steel,