Friction and stress distribution in coated steel sheet during forming

The use of lighter-gauge sheet of high-tensile steel for drawn panels has promoted the application of protective zinc or aluminium/zinc coatings. However, lighter-gauge sheet is more subject to loss of shape resulting from elastic distortion after removal of the forming load. In the present work, it was found that zinc and aluminium/zinc coatings change the friction stresses very little and coatings of the thickness employed cause little residual stress; they do not influence spring-back behaviour greatly. © 1990