Gilchrist, Percy Carlyle (1851-1935)

British metallurgist who devised a method of producing low-phosphorus steel from high-phosphorus ores, such as those commonly occurring in the UK. This meant that steel became cheaply available to British industry. Gilchrist was born in Lyme Regis, Dorset, and studied at the Royal School of Mines. He developed the steelmaking process 1875-77, together with his cousin Sidney Gilchrist Thomas. The product became known at first as 'Thomas steel'. Pig iron was melted in a convector similar to that used in the Bessemer process and subjected to prolonged blowing. The oxygen in the blast of air oxidized carbon and other impurities, and the addition of lime at this stage caused the oxides to separate out as a slag on the surface of the molten metal. Continued blowing then brought about oxidation of the phosphorus.