Patent AT-E399606-T1: [Translated] METHOD FOR INTERNAL HIGH PRESSURE FORMING A TUBULAR BLANK MADE OF STEEL

This invention relates to a method for manufacturing a metal tubular blank suitable for forming into a product comprising the steps of providing an essentially planar blank, said planar blank having a first surface and a second surface; producing the tubular blank from the planar blank whereby the second surface of the planar blank becomes the outside of the tubular blank; wherein a first layer with a first friction influencing function is applied to at least part of the first side of the planar blank and/or a second layer with a second friction influencing function is applied to at least part of the second side of the planar blank prior to forming the planar blank into a tubular blank, so as to influence the friction between the tubular blank and forming tools which can be used to form the tubular blank into the product, and wherein the first and/or second layer are applied in the form of a foil, a dry lubricant, a wax or an oil. The invention further relates to a tubular blank and a product produced from such a tubular blank.