Steel is an alloy of iron and other elements, primarily carbon, that is widely used in construction and other applications because of its high tensile strength and low cost.
The turning point of the Pacific Campaign of World War II was the naval Battle of Midway, which occurred between June 4 and June 7, 1942.
Midway was a turning point because the Japanese navy lost 4 aircraft carriers together with hundreds of planes and pilots and thousands of sailors. Naval power was no longer in the form of the battleship like in WWI. The real power was in the aircraft carrier, which could attack other ships and ground targets by air.