Activist investors go after a German industrial icon

White heat of change FEW industrial scenes offer the drama of a steelworks in full flow. Perched high in a cabin, a technician guides a bucket the size of a house to send 250 tons of lava-like molten metal into a vast crucible. As a roar echoes across a gargantuan hall, a pile of scrap slides into the mixture. Plumes of illuminated smoke rise. Sparks like giant fireflies tumble down. ThyssenKrupp's steelmaking plant in Duisburg makes 30,000 tons of the metal daily. The firm itself is going throu...