鴉片戰爭時期，中英鐵砲砲身均為鑄鐵組織，不同的是，清軍鐵砲以白口鑄鐵為主，英軍鐵砲則以灰口鑄鐵為主。在灰口鑄鐵組織中的石墨形態上，清軍鐵砲皆為片狀石墨；英軍鐵砲除片狀石墨外，還有菊花狀石墨，其占灰口鑄鐵總數的25%。由於菊花狀石墨組織的灰口鑄鐵性能比片狀或粗大的石墨構成的灰口鑄鐵要好，故英軍鐵砲材質優於清軍。此外，英軍鐵砲的鑄造及加工技術亦優於清軍鐵砲。由於鐵砲的材質、製造和加工技術直接關係著鐵砲的質量，而鐵砲質量則是影響鐵砲性能的最重要因素，故中英鐵砲性能上的差異是影響鴉片戰爭勝負的關鍵因素之一。 Although both cast in metal, Chinese cannons dating from the Opium War were different from the British ones in microstructure. First of all, the proportions of white iron and gray iron in the cannon bodies were different. The Chinese cannon bodies were largely cast in white iron, while the British ones were mostly cast in gray iron. Secondly, the shapes of graphite in the gray iron composition show some differences. In the Chinese cannons, the graphite is mostly in the form of flakes; however, in the British cannons, the graphite has two forms (75% flakes, 25% flowers). Flower-shaped graphite provides for better-quality gray iron. In addition, Britain had better casting and processing technologies. As a result of these factors, British cannons from the Opium War were of better quality than Chinese ones, and this, in turn, affected British performance. We believe that the difference in cannon composition was one of the major factors that decided the outcome of the Opium War.