Sheet Steel Surface Treatments for Enhanced Formability

Surface friction is an important characteristic which influences the formability of sheet steel products. Numerous friction tests have been developed, and many previous investigations have reported effects of surface characteristics, coatings, lubrication, etc., on formability. Recently, increased attention has been focussed on reducing friction via the application of solid film lubricants or special surface post-treatments such as phosphates, metallics/intermetallics, etc. This paper presents the results of selected laboratory evaluations conducted using a variety of steels and surface treatments. Formability was measured using Limiting Dome Height and Drawbead Simulator friction testing, along with Limiting Draw Ratio testing in one instance. The examples highlight some potential opportunities which may be considered for improving formability in industrial stamping operations.