The most significant innovation in the making of mild steel during the 20th century was made at Linz. Here in 1949 molten pig iron was decarburized by the insertion of oxygen lances to produce mild steel. This process, with many variations, is now used throughout the world. It is known as the basic oxygen or Linzer Dusenverfahren process or Linz Donawitz or LD process.
The steelworks at Linz is the largest industrial site in Austria and extends over 5.2 sq km. Stahlwelt (Steel world) is a multi-media centre which vividly illustrates every aspect of the history and manufacture of iron and steel, and can be experienced in 1,5 hours. Visitors who have more time can choose from a several tours. One, taking about 3 hours, is a tour by coach of the whole plant, usually, when the exigencies of steel-making operations allow, taking in the blast furnaces, the hot rolling mill, the terminal on the River Danube where raw materials are delivered, and the platinum plant. Another goes to a display inaugurated in 2009 commemorating 60 years of the LD process. The uses of steel in the manufacture of motor vehicles are highlight in another tour, which includes the plant where certain sections of steel are galvanised, and a section of the works where platinum, used as a catalyst in exhaust systems, is produced. Further tours are specifically designed for schoolchildren of particular age groups. A café above Stahlwelt offers panoramic views of the works.