Percy Carlyle Gilchrist
- December 16
) was a British chemist and metallurgist born in Lyme Regis, Dorset, and who studied at the Royal School of Mines. He is best known for his collaboration with his cousin, Sidney Gilchrist Thomas
on what became the standard method of making steel
The entailed producing low-phosphorus steel from high-phosphorus ores, such as those commonly occurring in the UK and this meant that steel became cheaply available to British industry.
He developed the process in 1875-77, together with his cousin and it involved melting pig iron 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.