Iron industry

China

In the 11th century, there is evidence of the production of steel in Song China using two techniques: the first a co-fusion technique, combining cast iron with wrought iron to obtain steel. Hartwell compares this with the European Berganesque process and discusses the resulting product's lack of homogeneity and thus quality. The second technique was a direct decarburization technique, working cast iron under air blast to remove carbon, which Hartwell associates with Song ironmaking and Shen Kuo's 1075 description. By the 11th century, there was a large amount of deforestation in China due to the iron industry's demands for charcoal. By this time however, the Chinese had learned to use bituminous coke to replace charcoal, and with this switch in resources many acres of prime timberland in China were spared.