Bubble Steel Sheet Metal for Very Light-Weight Structures 970154

In order to save more weight using steel sheet, Thyssen Stahl has recently completed research work on creating a very light-weight composite steel material. Two thin steel sheets currently as low as 0.30 mm in thickness are joined by local welds of a certain spacing. Prior to joining, locally formed, hemispherically shaped domes are used to keep the cover sheet metals at the intended distance. These depressions can be applied either to one, or even to both cover sheet metals. The total thickness of the final compound steel sheet varies from 1.0 mm to 1.8 mm. The material weight per unit area is equal to 0.7 mm, yet it is able to serve for certain mechanical properties of about 1.0 mm solid steel. A weight saving of 30 % seems possible for specific panel applications. Because of the similarity between the depression shape and a bubble, the material is designated as “Bubble Steel Sheet Metal”. In its flat as produced condition, this steel sheet is rigid and able to withstand bending loads. It is formable in common stamping tools, weldable within certain limits, and also has air-borne noise damping properties. Coated steel is used in order to fulfil corrosion protection requirements. The means to produce the material are still on a low-volume basis although the manufacturing process is computer-driven and semi-automatically operated. The blank size is limited to a max. 1250 mm x 1250 mm due to the welding equipment used.