See also the later, more detailed version.
Donald B. Wagner
Until very recently it was a reasonable hypothesis that the first use of iron in China was in the Southeast, perhaps in the 6th century BC, and that is the position I took in my book, Iron and steel in ancient China (Leiden: Brill, 1993, ch. 2-3). New finds, together with old finds only recently studied and published, have made this position untenable. It now seems likely that the technology of iron smelting diffused to China by the 8th century BC from the West via Scythian nomads in Central Asia.
Meteoritic iron had been used to some extent in China as early as the 11th century BC for the blades of luxury weapons, cast into bronze handles which were sometimes inlaid with silver or precious stones. The tradition of making luxury weapons with cast-in iron blades continues to about the 5th century BC, but in this period the makers shift from meteoritic to smelted (presumably bloomery) iron. The group of burials of the Guo state recently excavated near Sanmenxia, Henan, with cultural connections to the Northwest, five bronze-iron edged artefacts were unearthed, all clearly related in style, and on analysis it turns out that three are of meteoritic iron and two of smelted iron.
The following is tentative, for a good deal of material has not yet been properly published, and a further problem is that Russian archaeologists are divided on when or even whether the steppe peoples knew the technology of iron smelting. Nevertheless I suggest as a working hypothesis that the craftsman of an indigenous Chinese tradition of making luxury weapons with meteoritic iron blades, which were probably better than bronze weapons, at some time learned bloomery smelting from steppe peoples and began substituting bloomery iron for meteoritic iron. These weapons were probably not a match for bronze weapons, but by this time they were probably intended for display rather than actual fighting.
Perhaps it was not until this technology had spread to the Southeast that it was used to make anything useful. In most of China the only uses for bronze had been for ritual objects and weapons; the `barbarian' peoples of the Southeast were the first in the region of Chinese influence to use bronze agricultural implements to any great extent, and iron presumably provided a useful cheap substitute for bronze in this sort of application. It was probably here that iron casting was first developed, beginning with the carburisation and melting of iron blooms in the kind of furnace that was used to melt bronze. The blast furnace probably developed here as well, as bloomeries were optimised for the purpose of providing iron for casting rather than forging.