Austria: Steel’s Magic Wand

The LD oxygen furnaces at the Richard Thomas & Baldwins mill are the newest weapon that steelmen around the world are wielding to compete with cement, aluminum and plastics. Pure oxygen, when blown into steel crucibles, enables them to make steel faster and cheaper than ever before. Last August, boldly investing in the future despite poor current business, U.S. Steel Corp. announced that it will build two iso-ton “basic oxygen” furnaces at its Duquesne works. Last month. National Steel Corp. opened two 300-tonners at its Great Lakes works. In all, LD fur naces are now pouring steel in 17 nations from Japan to Portugal.

The LD process takes its name from the initial letters of Linz and Donawitz, two picture-postcard Austrian towns where the technique was first developed ten years ago. At the government-owned Voest steelworks along the Danube at Linz, scientists soon after World War II began seeking a way to make steel with less scrap—of which Austria has little. Joined by experts from another nationalized steel company, the Alpine Montan works of Donawitz, they derived the LD process from the principle, discovered a century ago by Sir Henry Bessemer, that pure oxygen speeds the cooking of iron, coke and limestone into steel.

In the LD process, a water-cooled, 30-ft.-long steel lance is lowered through the top of the furnace, like a narrow straw into a thick-walled cream pot, and sprays compressed oxygen at supersonic speeds over the bubbling mix. With a roar that would drown out a brace of jet fighters, the oxygen burns off the sulphur, carbon and other impurities in the white mass. Because it takes barely half an hour to cook a batch of LD steel, v. eight hours in the conventional, open-hearth furnace, the oxygen process melts the costs of labor, power and fuel. Production costs are about $3 a ton lower than in an efficient open hearth, and to build an oxygen furnace costs only half as much.

Today a majority of the world’s basic oxygen furnaces employ the LD process under license deals that furnish much of Austria’s foreign exchange. And tomorrow, say steelmen, every new steel furnace will use some kind of oxygen process.