I translated this article, and obtained permission from the lead author, Hua Jueming, to publish it, in 1984. He also supplied better photos for most of the figures. Unable to find a publisher for the translation, I laid it aside. I recently found it again, and publish it on-line here. I have made a few changes, including inserting the reference to an excavation report that had not yet been published at the time, but this is essentially the same translation that Professor Hua approved 35 years ago.

It should be noted that there is potentially a confusion, here and elsewhere, between SG-iron (also called ‘ductile cast iron’), an alloy which contains spherulitic graphite in the as-cast state, and malleable cast iron, which, depending on the precise alloy, after annealing, can contain spherulitic temper carbon.

Donald B. Wagner, 24 July 2019.

Ancient Chinese malleable cast-iron implements with spherulitic temper graphite

By Hua Jueming 华觉明, Li Jinghua 李京华, Guan Hongye 关洪野, and Ji Chengzhou 吉承周.
Translated by Donald B. Wagner 华道安.
22 June 1984.

Translator's note. By this time most archaeometallurgists are aware that whiteheart and blackheart malleable cast iron are both Chinese inventions, and were used as early as the third or fourth century BCE. Among the malleable cast-iron artefacts which have been found many contain spherulitic graphite. No explanation of how the ancient Chinese ironfounders could have achieved this structure has yet won general acceptance. It is generally assumed that spherulitic temper graphite can occur only in iron with relatively high sulphur and with the manganese-sulphur percentage ratio Mn/S < ca. 0.7 (e.g. Loper & Takizawa 1965), but the ancient Chinese artefacts have low sulphur (usually less than 0.05%) and often have Mn/S > 2. An article in the Chinese journal Qiutie (SG-iron) discusses the problem and describes in detail five ancient artefacts with spherulitic or compact temper graphite (Hua Jueming a.o. 1980). The following is a translation of these five descriptions.

1. Mattock-head from Nanyang, Henan

Figure 1. Cast-iron mattock-head from an ancient ironworks excavated at Wafangzhuang in Nanyang, Henan (artefact no. Tl:135). The scale shows cm.

This artefact (Figure 1) is either an agricultural implement or a craftsman's tool. It was unearthed in 1959 at the site of a Han-period (206 BC - AD 220) ironworks at Wafangzhuang, in Nanyang, Henan province 南阳瓦房庄 (HXKG 1991). It was sent for laboratory investigation to the Institute for the History of Science and Technology, Academia Sinica, in 1965.

Nanyang is located at the southern foot of the Funiushan 伏牛山 Mountains; the area is rich in iron ore and timber, and it was a famous center of iron production in ancient times. For example the Xun Zi 荀子, a book of the third century BCE, has: ‘The steel spears of Wan 宛 are as cruel as wasps and scorpions’ (Zhang Shitong 1974: 159; Watson 1963: 71–72). Wan was an ancient name for Nanyang. The Shi ji 史记, a book of the first century BCE, mentions a family of ironmasters named Kong 孔 who settled in this area at the end of the third century BCE (Shi ji 1962: 3278; Swann 1950: 454). Under the state monopoly of the iron industry, established in 117 BCE, one of the 47 Iron Offices established throughout the empire was here (Han shu 1962: 1555).

The Wafangzhuang ironworks site is precisely at the Han-period administrative seat of Henan Commandery. It is very large, with an area of about 120,000 square metres• There are three foundry areas and one smithy area. Large quantities of iron-smelting slag, firebrick, charcoal, blast-pipe fragments, and iron artefacts were found. Some of the iron artefacts have the inscription He yi 河一; this appears to indicate that the works was Ironworks No. 1 under the Henan Commandery Iron Office.


Figure 2. Microstructure of the mattock-head shown in Figure 1. Compact graphite.

The mattock-head was found in an Eastern Han (25–220 CE) stratum in test pit no. 1. It is complete, but almost totally corroded. See Figure 1. There is only a small amount of metal remaining, on the edge of the socket. In the cutting of samples a V-shaped shrinkage cavity, height 4 mm, was found at the centre of the cutting edge. Metallographic examination on the section A-A revealed relatively uniformly distributed compact graphite, similar to standard grade 2 graphite in rare-earth - magnesium SG-iron. It can be seen in Figure 2 that the form of the graphite is fairly regular, with clear boundaries; but graphite nuclei were not seen. With crossed nicols the graphite appears as scattered irregular aggregations, without a radiating structure. The matrix consists of coarse pearlite and ferrite. At the surface there is a decarburized layer (Shi Gang, forthcoming).

2. Axehead from Mianchi County, Henan

Figure 3. Cast-iron axehead from a trove in Mianchi County, Henan (style II, artefact no. 257). Ca. 10 × 12 cm.

This axehead (Figure 3) could have been used as a tool or as a weapon. It is one of a trove of over 4,000 iron artefacts found in Mianchi County 渑池县, Henan. The artefact types and inscriptions indicate that most of the artefacts are to be dated from the Wei period (220–265 CE) to the Northern Wei (386–534 CE), but that a few may be several centuries earlier (WW 1976.8: 45–51).

The axehead is complete and only slightly rusted. It has the inscription Ling you 陵右; this may refer to a military ironworks at the ancient city of Daling 大陵 in modern Wenshui County 文水县, Shanxi.

Laboratory examination in 1974 by the Beijing University of Iron and Steel Technology indicated that the axehead had been subjected to a decarburizing treatment. The

Figure 4. Microstructure of the axehead shown in Figure 3. Spherulitic graphite in a matrix of ferrite + pearlite.

metallographic structure for the most part corresponds to steel with about 0.4% carbon, with no temper graphite; but around the socket, in a U-shaped section 50 mm long and 3.2 mm thick, thirty graphite spherulites were found, with diameter about 20 μm. In this part the matrix consists of coarse pearlite and ferrite. analysis is:

C 0.6–0.9%  Mn 0.05%  S 0.02%  P 0.11%.

The cutting edge had been worked (Li Zhong 1975). We have further examined other parts of the socket, and found spherulitic graphite throughout; see Figure 4 for the form of the graphite and the structure of the matrix.

3. Mattock-head from Gongxian County, Henan

Figures 5–6. Cast-iron mattock-head from an ironworks site of the first century BCE excavated at Tieshenggou in Gongxian County, Henan (style II, artefact no. lin-5). Ca. 7 × 20 cm.

This mattock-head (Figures 5–6) was found in 1959 in the excavation of an ancient ironworks site at Tieshenggou 铁生沟 in Gongxian 巩县 County, Henan. The site is located at the northern foot of Songshan 嵩山 Mountain. The area of the site is over 20,000 square metres; there were found eighteen smelting furnaces, one melting furnace, and a large quantity of iron-smelting remains. Some of the iron artefacts have the inscription He san 河三, and this appears to indicate that this was Ironworks No. 3 under the Henan Commandery Iron Office (Gongxian Tieshenggou 1962).

On excavation the mattock-head was complete and only slightly corroded. It was examined in 1976 by the Chinese Archaeometallurgy Study Group. It has the typical characteristics of SG-iron (Figures 7–9). The graphite crystals are equi-axed polygons with regular form, corresponding to grade 1–2 graphite in the modern standard for SG-iron. Under polarized light it has a radiating structure. The matrix consists of pearlite and ferrite. At the surface is a decarburized layer. The chemical analysis is:

C 1.98%  Si 0.16%  Mn 0.04%  S 0.048%  P 0.297%

Figures 7–9. Microstructure of the mattock-head shown in Figures 5–6. Spherulitic graphite in a matrix of ferrite + pearlite.

Spectral analysis and electron microprobe analysis showed no clear traces of magnesium, alkaline-earth metals, or rare-earth elements. Nickel and chromium contents were very low.

The site is dated to the period from the mid-Western Han to the Wang Mang interregnum [i.e. about the first century BCE] Therefore this mattock-head is both the oldest and the highest-quality ancient SG-iron artefact yet found (KGXB 1978.1: 20).

4. Shovel-head from Mianchi County, Henan

In 1979 the Investigation Group for Ancient Cast Iron (formed by the Foshan SG-Iron Institute, the Institute for History of Natural Science, and the Henan Provincial Museum) discovered among the artefacts of the Mianchi trove two shovel-heads (artefact nos. Hl:312, Hl:321) which have spherulitic and compact graphite in their structures.

Figure 10. Compact graphite in a shovel-head from a trove in Mianchi County, Henan (artefact no. Hl:312).

The shovel-head is an agricultural implement. No. Hl:312 has the inscription shan 山 (mountain); this should, as in other inscriptions on early iron agricultural implements, be an abbreviation for a place name. It has not been possible to identify the place name intended, but it was probably in modern Laiwu County 莱芜县, Shandong. A shovel-head mould found in Laiwu in 1971 includes the same inscription in a similar calligraphic style.

This shovel-head has relatively round spherulitic graphite, as seen in Figure 10.

5. Shovel-head from Mianchi County, Henan

Figure 11. Compact graphite in a shovel-head from a trove in Mianchi County, Henan (artefact no. Hl:321).

Shovel-head no. Hl:321 has the inscription Jiangyi zuo 绛邑左. Jiangyi is an ancient place name in modern Quwo County 曲沃县, Shanxi. The designation zuo 左, "left", probably indicates a military unit, so it was probably produced in Jiangyi under the military production system of the Wei dynasty (220–265 CE).

Most of the graphite in this artefact is spherulitic or compact, but near the surface it tends toward a structure of accumulation of grains; it does not have the compactness required in modern SG-iron. See Figure 11.

Bibliography and abbreviations

Gongxian Tieshenggou 1962 巩县铁生沟 (The Han-period ironworks site at Tieshenggou, in Gongxian County, Henan), by the Archaeological Team, Henan Provincial Cultural Office. Beijing: Wenwu Chubanshe. English abstract pp. 39–40. English title: T'ieh Sheng Kou, Kung Hsien.

Han shu 1962 汉书 (History of the Former Han Dynasty [206 BCE – 7 CE), by Ban Gu 班固 [32–92 CE] and others; a modern critical edition). 12 vols., Shanghai: Zhonghua Shuju.

Hua Jueming 华觉明 (a.o.) 1980 ‘Liangqian nian qian you qiuzhuang shimo de zhutie 两千年前有球状石墨的铸铁’ (Spherulitic graphite cast-iron two thousand years ago), Qiutie 球铁 (SG-iron), 1980.2: 1–8.

HXKG = Huaxia kaogu 华夏考古 (‘Huaxia archaeology’)

HXKG 1991.1: 1–110 ‘Nanyang Beiguan Wafangzhuang Han dai yetie zuofang fajue baogao 南阳北关瓦房庄汉代冶铁作坊发掘报告’ (Report on the excavation of a Han-period ironworks at Wafangzhuang in Nanyang, Henan), by the Henan Provincial Museum.

KGXB = Kaogu xuebao 考古学报 (‘Acta archaeologia Sinica’).

KGXB 1978.1: 1–24 + plates 1–2 ‘Henan Han dai yetie jishu chutan 河南汉代冶铁技术初探’ (‘The iron and steel techniques of the Han dynasty in Henan’), by the Henan Provincial Museum; the Blast Furnace Plant of the Shijingshan Steel Plant, Shoudu Iron and Steel Company; and the Chinese Archaeometallurgy Study Group.

Li Zhong 李众 1975 ‘Zhongguo fengjian shehui qianqi gangtie yelian jishu fazhan de tantao 中国封建社会前期钢铁冶炼技术发展的探讨’ (‘The development of iron and steel technology in ancient China’), KGXB 1975.2: 1–22 + plates 1–6. English summary pp. 21–22.

Loper, C. R. & Takizawa, N. 1965 ‘Spheroidal graphite development in white cast irons’, Transactions of the American Foundrymen's Society, 72: 520–528.

Shi Gang 史刚, ‘Nanyang Wafangzhuang tieqi fenxi 南阳瓦房庄铁器分析’ (Analysis of iron artefacts from Wafangzhuang, Nanyang, Henan). [‘Forthcoming’ in 1980; not available to the translator.]

Shi ji 1962 史记 (Records of the Historian, by Sima Tan 司马谈 (180 – ca. 110 BCE) and Sima Qian 司马迁 (145 – ca. 86 BCE); a modern critical edition). 10 vols., Beijing: Zhonghua Shuju.

Swann, Nancy Lee (tr.) 1950 Food and money in ancient China: The earliest economic history of China to A.D. 25. Princeton, N.J.: Princeton University Press.

Watson, Burton (tr.) 1963 Hsün Tzu: Basic writings. New York & London: Columbia University Press.

WW = Wenwu 文物 (‘Cultural relics’)

WW 1976.8: 45–51 ‘Mianchi xian faxian de gudai jiaocang tieqi 渑池县发现的古代窖藏铁器’ (A buried trove of ancient iron artefacts discovered in Mianchi County, Henan), by the Mianchi County Cultural Office and the Henan Provincial Museum.

WW 1976.8: 52–58 + plate 4 ‘Henan Mianchi jiaocang tieqi jianyan baogao 河南渑池窖藏铁器检验报告’ (Metallographic examination of iron artefacts from the trove in Mianchi County, Henan), by the Department of Metal Materials and the Central Analytical Laboratory, Beijing University of Iron and Steel Technology.

Zhang Shitong 张诗同 (ed.) 1974 Xun Zi jianzhu 荀子简注 (Xun Zi, a book by Xun Kuang 荀况 [313–238 BCE], modern edition with brief commentary). Shanghai: Renmin Chubanshe.