The steel smelting technology of the Great Han Empire was mainly based on two-step smelting steel, integrated into the foundation of large furnace coke coal smelting. First, weaving iron is produced, and the wrought iron is sold to small blacksmiths or other trading companies. Weaving technology is used for military production, while agricultural iron tools are partially filled with steel. The process of liquid crucible steel has been systematically studied at Xiangyang Institute of Technology, but large-scale promotion is unrealistic and is still in the stage of small-scale production and exploration.

Ancient Chinese steelmaking technology

Number897Date:2005-4-13

Ancient steelmaking technology in my country was invented at the late Spring and Autumn Period. From the pre-Qin Dynasty to the middle and late Western Han Dynasty, the main steelmaking process was block iron carburizing; from the Han Dynasty to the Ming and Qing Dynasties, the main steelmaking method was steelmaking method and steel filling method, followed by the steelmaking method and iron cooking method. There was also "cast iron decarbonization steel" during the Han Dynasty, Wei Dynasty, Southern and Northern Dynasties, and there was also crucible steelmaking method in the Han Dynasty. The steelmaking process mainly produced general wrought iron (including steel and cooked iron). The steelmaking process mainly produced blade steel with high carbon content. Steelmaking is the reprocessing of ordinary steelmaking. The "cast iron decarbonization steel" and iron-burning steelmaking process will be introduced in Chapter 5, and the other five types will be discussed here.

1. The invention of steelmaking and the use of iron carburized steel

The earliest steel artifact in my country seen in archaeological excavations is the late Spring and Autumn steel sword unearthed from Yangjiashan, Changsha in 1976. The sword has a total length of 38.4 cm and a length of 30.6 cm. After analysis, the carbon content is about the same as medium carbon steel, and the structure is uniform and dense. The cultural relics excavation team of the construction project of the East Railway Station of Changsha: "The New Discovery of Steel Swords and Iron Tools in the Late Spring and Autumn Period in Changsha", "Cultural Relics" No. 10, 1978. It can be seen that ancient steelmaking techniques in my country were invented at the late Spring and Autumn Period. After the middle and late Warring States Period, steelmaking techniques developed rapidly in many places in the north and south of my country, and first reached a higher level in the Chu State in the south.

. "Records of the Grand Historian·Biographies of Fan Ju" says: King Zhao of Qin sighed and said, "I heard that the iron sword of Chu is sharp and advocates the superiority and clumsy." "Xunzi·大全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全全

"These sharp swords and halberds are generally believed by later scholars to be made of steel. Among them, Mingshan (now Xinxian), Tangxi (now Xinxian), Hebo (Xiping County), Feng Chi (Xingyang County) "Records of the Grand Historian•; Biography of Su Qin" quoted "Xu Guang said: There is Feng Chi in Xingyang". Suo Yin: "Wan people made swords in Fengchi, and they were called Wanfeng", "Deng's country had a sword-making worker, so they were named Deng Shi." Deng State discovered ancient iron smelting sites in the southeast of Luohe City, Henan Province. Longquan, Tai'a (all in Xiping County, and now under the jurisdiction of Wuyang Iron and Steel Plant). Dong Wen'an: "A Preliminary Study on the Origin of the Ten Swords in South Korea", National History of Metal Science

Papers of the Art Symposium, in 1989, Wuyang and Moyang are in Xichuan County, Henan Province. In 1965, 15 steel swords, 19 spears, and 12 halberds were unearthed from Tomb No. 44, Yanxiadu, Yi County, Hebei Province. People analyzed 6 of them, except for one of them as a block of iron making, the remaining five were made of steel. Beijing Institute of Steel Pressure Processing: "Preliminary Report on the Metallurgy of Iron and Metallurgy of Tomb No. 44, Yi County Yanxiadu, Yi County". "Archaeology" No. 4, 1975, the excavation report is found in the same issue "Brief Introduction to Excavation of Tomb No. 44, Yanxiadu, Yi County, Hebei Province" in the same issue. It shows that the steelmaking technique of Yan State in the north had also developed.

The steel smelted in early humans is generally made of low-temperature reduction and smelting. The whole process is about two steps: the first step is to extract the ore from the ore to make iron, and the second step is to carburize the iron from the block to make steel. During this carburizing process, it is necessary to continuously fold and forge to help the diffusion of carbon. The steel obtained in this way is called block iron carburizing steel. The weapons such as Yanxiadu Steel Sword are made of this steel. If controlled properly, there are also those that are reduced and smelted into steel without going through the second step. This steel is called block steel or natural steel. The strength and hardness of these two steels are more powerful than block iron.

High. The disadvantages are: (1) The carbon content is generally low. (2) The carbon distribution is often not uniform enough. (3) The steel is often filled with more inclusions. (4) The productivity is low. In the Central Plains Cultural District, this steelmaking process was used until the middle of the Western Han Dynasty, and was gradually replaced due to the invention and development of steel frying. The Liu Sheng sword and the Cuojin Shudao unearthed from the Han tombs in Mancheng are all made of iron carburized steel. The inclusions are less than that of the Yanxiadu steel sword, and the structure is also relatively uniform and dense. This steel is mainly used to make swords and other weapons, and is rarely used in agriculture and handicrafts.

2. Steel frying and its process operations

The steel stir-frying process is a kind of semi-liquid smelting. It uses pig iron as raw material. After heating the pig iron to the liquid semi-liquid, it uses oxygen in the blower to decarbonize the pig iron to the composition range of steel and cooked iron. During the smelting process, the metal must be constantly stir-fried. It was called "cracking" in ancient times. Before the 1950s, it was commonly called stir-frying and stir-frying "cracking iron".

(I) The invention and development of steel frying

Ancient steel frying technology in my country was invented around the middle and late Western Han Dynasty. The earliest relics now include: Han Dynasty steel frying furnace unearthed from smelting iron sites such as Tieshenggou in Gongxian, Wafangzhuang in Nanyang, Gudeng Village in Xin'an, and 14 fried products such as iron blocks, residual iron hoes, and iron trunks unearthed from Tieshenggou. The Tieshenggou steel frying furnace is a small shaped pit dug underground, coated with refractory mud, length 0.37 meters, width 0.28 meters, and residual height 0.15 meters. The wall of the furnace has been burned black, and an iron block remains in the interior. Henan Provincial Cultural Bureau Cultural Relics Work Team: "Tieshenggou in Gongxian", Cultural Relics Publishing House, 1962 edition,

Zhao Qingyun et al.: "Another Discussion on the Smelting and Casting Site of Tieshenggou, Gongxian," Journal of Archaeology, No. 2, 1985. Records of steel frying in ancient my country were first seen in the middle and late Eastern Han Dynasty. Volume 72 of "Taiping Jing" says: "Now military soldiers are an ominous tool... If you are anxious, you will then send craftsmen to strike and treat stones, ask for iron, burn them and smel them, and make them water. Then you will use good craftsmen to forge them, and then you will use thousands of good crafts to forge them to form Moye?" This "Moye" refers to sharp weapons. The three sentences such as "burning and smelting" refer to the entire process of frying and smelting and making tools. "Taiping Jing" is a Taoist work and basically maintains the original appearance of the middle and late Eastern Han Dynasty.

The invention of stir-fried steel quickly changed the use of wrought iron in our society. From 1952 to 1953, Luoyang Shaogou excavated 225 tombs from the mid-Western Han Dynasty to the late Eastern Han Dynasty, and 116 steel knives, 33 swords, 5 spears and 4 axes were unearthed. Among the bronze weapons and blades, there were only 7 bronze knives (ceremonial instruments), 1 spear, and no sword. Institute of Archaeology, Chinese Academy of Sciences: "Luoyang Shaogou Han Tomb", Science Press, 1959 edition. From 1957 to 1958, 217 same were excavated in the western suburbs of Luoyang.

During the Han tombs of the period, 52 steel knives, 58 swords, 1 halberd and 1 axe were unearthed; only 1 bronze weapon was slashed. Luoyang Excavation Team of the Institute of Archaeology of the Chinese Academy of Sciences: "Report on the Excavation of Han Tombs in the Western Suburbs of Luoyang", "Journal of Archaeology" No. 2, 1963. After the mid-West Han Dynasty, except for crossbows and horns, other weapons and blades were mostly made of steel, and the raw materials were obviously fried steel. In this way, steel objects completely replaced the dominance of bronze and wood and stone in agriculture, handicrafts and military aspects.

The steel stir-frying process was used in my country from the Han Dynasty to the Ming and Qing Dynasties. Relevant records can be seen in the Tang Dynasty's "Xiahou Yang Suanjing", Song Susong's "Tujing Materia Medica", Ming Tang Shunzhi's "Wu Bianqian", Zhao Changji's "Divine Artifacts Collection", Zhu Guozhen's "Yongzhuang Sketches", and Qu Dajun's "Guangdong Xinyu" and other books. Volume 15 of "Guangdong Xinyu" "Civilized Iron" says: "The iron stir-frying is made into the furnace with a pig iron ball, and it is burned red and then it is placed on an anvil, one person clamps it, two or three people hammer it, and more than ten boys next to it fan it. The boy must sing and then be refined and made into a pot." Volume 5 of Geng Buchan's "Shanxi Mining Affairs" published in 1920 says: "Put the refined pig iron is added to the coal powder and burn it, and it is turned into iron juice. After it is cold, it is placed in the stir-frying furnace to stir-fry it, and then it is mature. "In the 1980s, this method was still produced in Youxian, Hunan and other places.

The advantages of the steel stir-frying process are: (1) Pig iron used as raw materials is easy to obtain, which expands the source of raw materials. (2) Smelting is carried out in semi-liquid state, and decarbonization is relatively rapid and productivity is high. (3) The composition range is wide. According to analysis, the steel stir-frying material produced by Tieshenggou contains 1.288% carbon, 0.231% silicon, 0.017% manganese, 0.024% phosphorus, and 0.022% sulfur, which is equivalent to overeutically euthanized high-carbon steel; the other component is: carbon 0.048%, silicon 2.35%, trace amount of manganese, 0.154% phosphorus, and 0.012% sulfur, which is comparable to today's mature iron.

Dang. Li Zhong: "A Discussion on the Development of Steel Smelting Technology in the Early Period of Chinese Feudal Society", Journal of Archaeology, No. 2, 1975. Scholars in the present world often call the process of first smelting of pig iron first and then pig iron steel. The emergence of steel frying is the starting point of two-step smelting, and it has an important position in the history of world metallurgy. In Europe, similar processes to steel frying appeared in the 16th and 17th centuries, and the dominant part of the entire medieval era were the natural steel method and the block iron carburizing method. Therefore, the supply of wrought iron was not sufficient for a long time, which naturally had an impact on social progress.

The steel frying method is the basic process of the production of wrought iron in ancient my country. Its main uses are three: (1) to make general forgings. From the Han Dynasty to the Ming and Qing Dynasties, the forgings in my country, including production tools, daily necessities and weapons were roughly made of stir-frying steel and reprocessed products. (2) Used as raw materials for steel frying. (3) Used as raw materials for filling steel.

(II) Process operation of steel frying

There are three main types of steel speculation in my country:

(1) Single-chamber frying. The basic feature is that metal smelting and fuel combustion are carried out in the same furnace. This method was invented earlier and has been used for a long time. The Han Dynasty frying methods of Tieshenggou, Nanyang Wafangzhuang, and Xin'an Gudeng Village all belong to this category. In the 1950s, a "ground furnace" was popular in Henan, Shanxi and other places. The furnace was built below the ground, which was like a crook or straight cylinder, and the furnace mouth was straight to the ground. During smelting, charcoal (coal) was first placed first, and then the pig iron needed to be crushed, and then covered with coal powder. Then ignite, send air, and close the furnace mouth. When the pig iron is approaching melting, the furnace mouth is opened and the metal is constantly stirred with iron rods or wooden sticks. As the stir-frying progresses, the carbon fraction continues to decrease, and the melting point of the metal increases, and it is bonded into a sponge-like solid block, and then the hammer is clamped out.

Eliminate inclusions and give a certain shape, which is fried products. A "table furnace" has been popular in some southern provinces. The furnace is built on a special furnace table and has a larger heating and fried space. The fried furnace in Wenzhou area is made of bricks, like a chicken cage, with the bottom of the furnace close to the ground plane, and the fried room is an irregular rectangular space. There is a furnace opening on the front of the furnace, where the feed, operation, steel is produced, and thus the waste gas is escaped; the blower enters from the bottom of the furnace and is facing the middle of the furnace; the operation method is similar to the ground furnace. There is also a similar furnace in Youxian, Hunan. The Wenzhou fried technology system surveyed in 1977, and the Youxian steel fried system surveyed in 1980, and they were all in production. The advantage of single-chamber fried is that the equipment is simple, and the disadvantage is that the metal and fuel are in direct contact, which often contains more harmful inclusions.

(2) Double-chamber frying, or a reflector (inverted flame furnace) frying. The basic feature is that fuel combustion and metal smelting each occupy an independent space. The high-temperature flame flow generated by fuel combustion passes through the fire wall (fireway) and enters the smelting chamber, heats the metal, and then discharges from the furnace door or specially set up chimney. Because the metal does not come into direct contact with the fuel, the possibility of harmful impurities phosphorus and sulfur entering it is reduced. The invention time of this steelmaking method remains to be found. It is published in 1935

The seventh edition of "China Industrial Chronicle (Hunan Province)" says: "The local steelmaking in Shaoyang, Wugang, Xinning and Xiangtan County in Hunan Province has a long history. Shaoyang was originally named Baoqing, and the steel produced in it is called "Baoqing Datiao Steel". Wugang near Shaoyang and Xinning are produced in Shaoyang, and people in the industry are also named "Baoqing Datiao Steel". In the early Qing Dynasty, Baoqing Datiao Steel was very famous and produced a lot, and was the first to be Shaoyang Nanxiang." Because Baoqing Datiao Steel is made of inverted flame furnace, this record shows that it is evident from this section.

, the reflection furnace should have been invented before the early Qing Dynasty. The earliest inverted flame kiln seen in archaeological excavations is a row of six glazed kilns built in the early years of Hongwu, which was discovered in the Yanxiang Temple in Nanjing. Nanjing Museum: "Nanjing Jubaoshan Glazed Kiln in the Ming Dynasty" and "Cultural Relics" No. 2, 1960. In 1958, this inverted flame furnace steelmaking was used in many places in the north and south of my country. The furnace in Lushan, Henan is relatively simple, with two rooms close to each other, both built below the ground, and the blower blows from the combustion chamber

The lower part enters, and then enters the fried room from the top of the fried room. The furnace in Xi'an is another example. The fried room is built below the ground, the combustion room is built above the ground, and the two rooms are superimposed up and down, and the bottom of the combustion chamber is opposite the center of the fried room. The wind bulges from the upper part of the combustion chamber, and then shoots directly into the fried room through the fire outlet at the bottom of the combustion chamber. The top mouth of the combustion chamber is closed with a cover plate. Edited by Science and Health Press: "Civilized Low-Temperature Steel Making" Vol. Sixth "The Simplest Reflector Steel Making", 1958 edition.

(3) Frying in series. The relevant records are only found in the "Iron" Volume 14 of "Tiangong Kaiwu" by Song Yingxing of the Ming Dynasty: "If you make cooked iron, then when the pig iron flows out, it will be connected within a few feet, lowered by several inches, and built a pond with a short wall. The iron flows into the pond, and several people hold willow sticks and stand on the wall. First, dry it with dirt mud. Pound the fine silk as flour, and one person sprinkles with his hands quickly. The willow sticks are stir-fried and cooked immediately. The willow sticks are fried twice each time, and the willow sticks are fried.

If you use it again, then it will be changed. When it is slightly cold, some people may cut into squares in the pond, or some people may propose to wield the vertebrae and round the goods. If you are smelted in Liuyang, you don’t know if this is the case.” (Figure 2-3). This "dirty sludge" is likely to be a slag-making flux. Here we talk about the entire process of tandem stir-frying. The advantage of this method is that the pig iron flows directly into the square pond after it is released, which saves the pig iron reheating process, thereby saving working hours and reducing costs.

It should be noted that the ancient word "cracked iron" was mentioned twice in the above quotation. It is often seen in other ancient documents that its meaning is different from that of modern crucian iron. The ancients did not have the concept of carbon content. The main basis for distinguishing pig iron, steel, and crucian iron is its use performance. The hard and brittle ones are "raw", the forging ones are "craved", and the strong ones are "hard and steel" are steel. Because the frying process is carried out in a semi-liquid state, it is difficult to separate slag iron, and the product contains

The mixed content is often more. Even if the carbon content is high, its nature is not strong, and it can only be called "fried iron". The "Occasional Record" article in the Volume 2/19 of "Jingwu Kuan" forged by the Yuan Dynasty said: "The ground is like mud, with gold color, and a fishy smell. The soft iron burns red and throws it twice or three times, and it can be cut into jade." This "soft iron" means "fried iron". Su Gong's "Tang Materia Medica" says: "Soft iron is also cooked iron." This is to distinguish steel from "fried iron" based on material properties. Su Song's "Tujing Materia Medica" says: "First refining

The one who removes ore and casts the utensils is pig iron. After repeated sale and sale, the one that can be used as a slaughter is iron, which is also called ripe iron." Su Gong's "Tang Materia Medica" and Su Song's "Tujing Materia Medica" are all quoted from Volume 8 of "Compendium of Materia Medica". This is to distinguish steel and iron based on material properties and smelting technology. Volume 14 of "Iron": "Any iron is cooked when it is cooked when it is cooked, and it is cooked when it is fried." Here, smelting technology is used as the standard for distinguishing steel and iron.

Some scholars regard the "cry iron" in ancient times as equivalent to modern times as cooked iron, and include the process of stir-frying "cry iron" in Volume 14 of "Tiangong Kaiwu" in the ironmaking process. We believe that from the perspective of carbon content, the "cry iron" in ancient times should be equivalent to today's wrought iron, that is, it should refer to all forged iron-carbon alloys with carbon content below 2%. He Tangkun: "Two Issues on Steelmaking Technology in the Ming Dynasty", "Research on the History of Natural Sciences" Issue 1, 1988-

3. The essence of steelmaking and its technology

(1) The emergence and development of steelmaking in 100

As mentioned earlier, steel frying is carried out in a semi-liquid state, so it is still difficult to separate slag and iron. Only through repeated forging can the inclusion be further eliminated. Under certain conditions, the more repeated forging, the more sufficient inclusion is eliminated, the better the quality of the steel, so a process is produced that uses "refining numbers" to indicate the quality of the steel. He Tangkun: "Hundred Steel Making and its Processes", "Collected History of Science and Technology" Volume 13, Shanghai Science and Technology Press, 1985 edition.

In ancient my country, steel processing technology that uses craftsmanship was first seen in the early and mid-term Eastern Han Dynasty. In the beginning, there were "300" and "500" and so on. In 1978, Tongshan County, Xuzhou City collected a 500 steel sword. The total length was 109 cm, and there were 21-character gold inscriptions on the front of the sword handle: "In the second year of Jianchu, Wang Yan, the western engineer of Shu County, built 500 □□□ Sun Jiankou." "Xuzhou Museum: "The discovery of 500 □2 of Jianchu in Xuzhou in Xuzhou" and "Cultural Relics" No. 7, 1979. Jianchu" (76-84) is the reign of Emperor Zhang of the Eastern Han Dynasty, and "大" is the same as "大". In 1974, Cangshan County, Shandong Province, a 300 steel sword was collected, with a total length of 111.5 cm. The knife

There are 18-character gold inscriptions on the back: "The 30-ton gold sword was built in Bingwu, May 6, 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 2005, and 200

According to the existing information, the theory of "Hundred Steelmaking" appeared around the late Eastern Han Dynasty. By the Wei, Jin, Southern and Northern Dynasties, this technology reached a relatively prosperous stage. In 1961, a hundred steelmaking knife was unearthed from the ancient tomb of Todajiyama, Libien Prefecture, Nara Prefecture, Japan. It is 103 cm in length and has 24-character gold inscriptions on the back: "Zhongping □ May Bingwu made a supporting knife, Bailianqing, and the star supi." Zhongping (184-189) is the reign of Emperor Ling of the Eastern Han Dynasty.

. Umehara Moji: "The Iron Knife of Hanzhongping Chronicle (Oral Paintings and Readings) Unearthed from the Ancient Tomb of Liben Le Dajiyama, Nara Prefecture", "Journal of Archaeology" Volume 48 No. 2. This is the earliest physical object of steelmaking today. At this time, there are also more records. "Yiwen Leileju" Volume 59 quotes Chen Lin's "Wu Jun Fu" and says: "Aujian is the Donghu Quegong, and the hundred refined steelmaking is the name of Jia." Quegong is the name of Jia. "Taiping Yulan" Volume 3,45 quotes Cao Cao's "Inner Commandment"

Cao Cao once made "a hundred refining tools to prevent bad luck". Cui Bao of Jin's "Ancient and Modern Notes·; The First of Yufu" says: "The Emperor of Wu had three precious swords,... One is a hundred refining, two is a green calf, and three is a leaking scenery." Volume 3,46 of "Taiping Yulan" quotes Tao Hongjing's "Sword Record": "The Lord of Shu Liu Bei ordered Pu Yuan to make five thousand swords, all of which were serialized, and the blade was engraved with 72 tons." It can be seen that Wei, Shu, and Wu had made famous swords with "a hundred refining" or marked with other refining numbers.

Sword. Volume 130 of "Book of Jin" says that when Helian Bobo became king in Xia (407-431), he also "made a sword of steel making for a hundred steel making, which was a ring of dragon birds." Volume 665 of "Taiping Yulan" quotes Tao Hongjing: There was a kind of "horizontal method" in the Southern Dynasty, which was also made of "hundred and hundred tempering". Literary scholars often used "hundred and hundred tempering" as a metaphor. Among them, the most popular one is Liu Kun's poem "Redeemed to Lu Chen": "Why do you mean to make steel making, and turn it into softness around your fingers."

After the Tang and Song dynasties, due to the development of steel filling technology, the 100 steel making has decreased, but this craft has been used. Volume 169 of "The Emperor's Department" says that there was a "nine-refined pure steel" in the Five Dynasties, Shen Kuo's "Mengxi Bitan" says that there was a 100 steel making in Cizhou in the Northern Song Dynasty, and the 600-refined steel making in the Song and Zhou dynasties "The Rise of the Lingwai" Volume 6 "Ban Knife" Article, and the 100-refined steel making in the Ming Dynasty Volume 10 "Hammer Forging·; Jin Axe" Article, and Huang Mian of the Qing Dynasty's "Flying Bomb Cannons" all talked about "100 steel making in the Steel". The 100 steel making technology has also been passed down to Korea and Japan. There are seven swords handed down from the Ishikami Temple in Nara Prefecture, Japan.

The sword is shaped like a tree branch, and the single branch is in the shape of a sword. It is a weapon made by King Baekje for the King of Japan. The sword body has 33-character gold inscriptions: "On May 16, the fourth year of Tai, Zhengyang made seven swords with hundreds of iron training, and hundreds of soldiers were detained in the world, and it is suitable for the King of Marquis to be made." "Taihe" (366-371) is the year of the Abandoned Emperor of the Eastern Jin Dynasty. A large steel knife was unearthed from the ancient tomb of Chuanshan in Kumamoto Prefecture, with silver inscriptions and horse-shaped patterns on the back, called "Eighty Tons", which may be an object from the fifth century AD. "Japan" Volume 3 of "World Archaeology" The steelmaking process had many important influences on Japanese swords.

(2) Process operation of steelmaking in 100

Volume 3 of Shen Kuo's "Mengxi Bitan" says: "I went to Cizhou to visit Cizhou and watched the iron crafting in the forging workshop to understand the real steel. Any iron with steel is like steel, if there are tendons in the face, and the soft surface is washed, the gluten will be seen, and the same is true for steel. But if the fine iron is forged for more than a hundred fires, each forged, it will be called light, and it will not be reduced until it is fed, then pure steel is, even if it is refined, it will not be consumed. This is the pure iron, its color is clear and bright, and it will be dark and black, which is common.

Iron is very different. Some people who have been refined at the end but no steel are all produced by the ground. "This "fine iron" refers to the raw material of steelmaking, which should be an iron-carbon alloy with a slightly higher carbon content and does not contain much inclusion. "One forging and one light" should be the continuous removal of inclusions, and the iron oxide sheet will continue to produce and fall off. "It is forged and not reduced in weight" should be relatively speaking. "It is refined at the end but no steel" may contain more sulfur and produce hot and brittle

Because of this, this is the most detailed passage in ancient Chinese literature about the process and principles of steelmaking in steelmaking. It can be seen that "Hundred Fine" means "Hundred Fine" and the center link is repeated forging. "Hundred Fine" is a kind of "pure steel" after removing the inclusions. From the perspective of modern technical principles, repeated forging can be evenly composed and densely organized, and sometimes fine grains, thereby greatly improving the quality of the material. Xu Shen's "Shuowen Jiezi" says: "Forging is also small syr." This makes sense. Some scholars believe that the central link of "Hundred Fine" is carburizing, and steelmaking is a kind of carburizing steel; some scholars believe that the central link of "Hundred Fine" is decarbonization, and steelmaking is a kind of pig iron decarbonization, which is a misunderstanding. We think that although the carbon content of metals may change during the process of refining, this is not the purpose of refining.

Regarding the specific operation of "Hundred Refining", from the perspective of many aspects of information, it should include at least three types:

(1) Multi-layer stacking and forging are legal, that is, many blocks are stacked and forged together. The components of these raw materials can be the same or different; they can also be folded again after stacking and forging. There are three aspects of information that can be proved.

First, it is documentary records. According to Cao Zhi's "Bao Dao Fu", during Jian'an, Cao operated five treasure swords. Cao Cao called this knife a "hundred-refining weapon" in the "Inner Commandment" and also called it "hundred-refining sword" in the "Bao Bi Dao Ling". "Bao" is a fold, multi-layered and folded repeatedly. It shows that this "hundred-refining" is a specific way of "hundred-refining".

The second is physical data. Scientific analysis shows that the metallographic structures of the "Santhak Knife" in the sixth year of Yongchu and the "Fifty-Ten" long sword in the second year of Jianchu were obviously layered. The former sampled at the blade and the carbon content is about 0.6-0.7%, the inclusions are thin and dispersed, with a large deformation, and a uniform distribution, with roughly about 30 layers. The latter is divided into three parts, and the central part can be divided into about 15 layers, with a carbon content of 0.7-0.8%, and the tissue is evenly formed; the two sides are symmetrical, each with

The carbon content is not very uniform at about 20 layers, with the high carbon part being 0.6-0.7%, and the low carbon part being 0.3-0.4%, totaling more than 50 layers. Ke Jun et al.: "Old Steel Making in Ancient Chinese", "Research on the History of Natural Sciences" Issue 4, 1984. It can be seen that in the early 10 steelmaking process, there was a certain relationship between the number of 10 steelmaking and the number of tissue layers. Of course, not all 10 steelmaking is like this. "Old" should be too much, rather than a strict digital index.

The third is Japanese knife technology. According to research, the skin and core of Japanese knife are often forged from multi-layered materials. The leather is often made of "yu steel" with a carbon content of about 1.3%. First forged the jade steel into many small pieces, then folded horizontally and vertically. It is said that it must be folded repeatedly 23 times. The heart is often mixed with "fu Ding iron" and "yu steel" with slightly lower carbon content, with a ratio of 2:1. After being forged, it must be folded more than 10 times. Uchida Teno: "New Study on the Great Japanese Sword", 1934, pages 297, 298.

(2) Single material is repeatedly folded and forged. Before folding, if the material is one layer, after folding, 2n layers will appear. Modern Longquan Sword once said that "Nine Refining" is the saying, "Nine" also means "long", but the actual number of forgings depends on the quality of the raw materials and the requirements for product performance, and it usually takes half a day forging. Japanese knife also has similar operations. Some people say that the new knife period needs to be folded 15 times, and 32,768 layers of tissue were obtained; some people say that the modern Japanese knife only folded 7-8 times, and 128 or 256 layers of tissue were obtained Honma Shunji: "Japanese Knife", Iwahara Bookstore, 1939, pages 34-36. Under a metallographic microscope, this tissue can sometimes be decomposed, but sometimes cannot be distinguished.

(3) Rotary forging is legal. Wei Yuan's "Haiguo Tuzhi" quoted Huang Mian's "Flying Bomb Cannons" as saying: "Use iron bars to burn and melt them for hundreds of times, and gradually rotate them into a ball, and only every five kilograms can be refined into one kilogram." According to investigation, before the 1930s, there was a similar operation in Beijing's treasure knife technology, but the number of times it rotates and forging depends on the situation.

Due to the difficulty in making steel and low metal collection rate, it is mainly used as precious objects such as swords and swords. It has few applications for ordinary blades and production tools.

4. Steel filling and its process principles

The steel filling process is the main method of the production of blade steel in ancient my country. It uses pig iron and "cracker iron" (a fried product with a high carbon content) as raw materials, heats them above the melting point of the pig iron, and combines them to form steel.

(I) Invention and development of steel filling technology

The records of steel in ancient my country were first seen in the late Eastern Han Dynasty. Volume 91 of "Complete Later Han Chinese Text" Wang Can (177-217) "Blade Inscription" says: "In the time, yin and yang are used to make soldiers, and all color agents are used to examine the turbid and clear; the folds have been counted, and the quality has been shown. The back loads are reversed and the shapes are staggered." This article describes the entire process of making a treasure knife. The "filling" means tweaking, and "filling" originally refers to the pleats on clothes, which should refer to the multi-layer stacking of steel materials and repeated folding. "filling has been counted" means multiple infusions. It can be seen that in the late Eastern Han Dynasty, people used steel to make swords, and their invention was at the latest in the late Eastern Han Dynasty. He Tangkun: "Several Issues About Steel Insert", "Collected History of Science and Technology" Volume 15, Shanghai Science and Technology Press, 1989 edition.

Later, Zhang Xie of the Jin Dynasty also talked about the craft similar to that mentioned in Wang Can's "Blade Inscription": "There is more than the sheep's head, and the slurry (钟) is forged, and it is refined and melted, and thousands of times are slurry; the slurry is flourishing, and the charcoal is flying in full bloom." This "slurry" was quoted by Li Shan of the Tang Dynasty as "pig iron". Li Shan interpreted it as "Guangya" as "selected". Li Shan's notes said: "Bi means stacking, and pouring means casting." Volume 35 of "Selected Notes of Six Ministers" Zhang Xie's "Seven Times" Notes. Therefore, this "10,000-pig" refers to multiple layers and multiple times of filling, which is the steel filling process.

During the Northern and Southern Dynasties, steel infused was promoted in the north and south of my country and used in the production of agricultural tools. Volume 4 of "Repairing Zhenghe Classics and History of the Preparation of Materia Medica" quoted Liang Tao Hongjing: "Steel is a mixed practice of raw croaker and made of sickles." Qi Wuhuaiwen of the Northern Qi Dynasty also made steel infused swords. In the Song Dynasty, there were more records. Volume 78 of Zhang Junfang's "Yunji Qixuan": "When it is poured, charcoal such as Linli must be used, and the rest are not worth using it." It also says: "Picking naturally into iron, and then taking the pounding of hard and five poundings are better." Volume 4 of "Repairing Zhenghe Classics and History of the Preparation of Materia Medica" also quoted Su Song of the Northern Song Dynasty: "The one who uses softness to mix and use it as a sword and sword sharp blade is steel." Steel infused was used in my country until the Ming and Qing Dynasties, and was still popular in Sichuan and other places in the 1930s.

Li Shizhen's Volume 8 "Compendium of Materia Medica" Volume 8: "There are three types of steel, including pig iron and cooked iron, some refined iron and steel, and some produced in the mountains of the southwest sea, like purple quartz." The former is steel filling, the second is steel making, and the latter is a diamond error. It can be seen that in the minds of the ancients, steel filling was one of the main varieties of ancient steel in my country. Because of its high carbon content, it is usually mainly used to make weapons such as knives, swords, sickles, and other weapons, and the edges of production tools, which played an important role in the development of production in ancient my country's society.

(II) Process operation of steel filling

There were few records in this area before the Song Dynasty, and there were at least three different craft types after the Song Dynasty.

The first method is to trap pig iron. Volume 3 of Shen Kuo's "Mengxi Bitan" says: "The so-called steel in the world is to use soft iron to curl it, then use pig iron to trap it and seal it with mud and smel. Forging it into it is called round steel, also called stuffed steel." This "soft iron" is the ancient "melting iron". There are three functions of this "soft iron": (1) Make all parts of the iron material uniformly heated and allow pig iron to melt slowly. (2) prevent the loss of pig iron after melting, so that it can better function with soft iron. (3) prevent and reduce the burning of carbon in the furnace gas.

The second type is the method of covering pig iron. Song Yingxing's "Tiangong Kaiwu" Volume 14 says: "For the method of crafting steel, use cooked iron to make thin slices, such as a wide finger head, about half an inch long, and wrap the tip (clip) with iron sheets, and place the soil of pig iron (Part 1) (Original note: Guangnan pig iron is called "False Born Steel". He also uses broken grass shoes to cover it (Original note: Those who stick to soil, so they cannot be quickly transformed), and apply mud under it. When the fire power arrives, the raw steel will first be transformed, seeped into the cooked iron, and the two are in love. Take it out Add a hammer, then refine and hammer, and it will be more than the same. Commonly known as tumble steel, it is also called steel filling." This operation has made some progress compared to the method of falling into the pig iron: (1) Pig iron is placed on "cooked iron" and seeps downward after melting, which increases the chance of raw and "cooked" iron contact reaction, reducing the chance of pig iron loss. (2) There is no need to seal mud, but the upper cover is broken and the grass is applied to the bottom, which simplifies the operation. (3) "cooked iron" is thin, increasing the reaction surface and improving productivity.

The third type is pig iron pouring method. It was founded around the mid-Ming Dynasty and was prosperous in Wuhu, Anhui, Xiangtan, Hunan and other places during the Qing Dynasty. It is said that it was founded by craftsmen in Jiangsu, and it is also known as "Sugang".

The "Iron" article in the "First Edition of Wubian" by Tang Shunzhi of the Ming Dynasty said: "There is no source of cooked steel, and it is made of cooked iron and made of cooked iron. It is made of cooked iron and can be clad with cooked iron, and the pot is covered with mud and fire and then cast with pig iron and 'cooked iron'. When it is very mature and the pig iron is about to flow, it is used to rub it into it." This "cooked steel" is steel filling. Here are two operations. The former is similar to what Shen Kuo said, and the latter is the Su steel process.

Volume 1 of Chen Chunhua's "Jiaqing Wuhu County Chronicle" also contains Su Gang's records: "Doctors of steel industry in the iron management industry, and hundreds of people have to work every day. First, they forged "mixed iron" in the furnace, and Xu Yisheng sucked it, called "mixed iron". If the slag is full, it will not be filled. At that time, the dregs are gone, and they will be hammered and stripped to form steel." Volume 11 of the "Guangxu Xiangtan County Chronicle" published in 1935, the seventh chapter of "China Industrial Chronicle (Hunan)" is said that Xiangtan Su Gang was passed down from Wuhu during the Qianlong period. It can be seen that Wuhu Su Gang was more developed in the early and mid-Qing Dynasty.

Compared with the first two methods, the advantages of Sugang operation are: (1) Its "fried iron" is only forged, and the tissue is relatively loose, which increases the rawness. The "fried" iron contacts the reaction surface and contains more oxidation inclusions, which can improve the strength of the carbon and oxygen reaction and enhance the slag removal ability. Moreover, some ferrous oxide can be reduced, which increases the metal yield. (2) Pig iron does not directly cover the "fried iron" or is not sandwiched between "fried iron", from "big iron to

"Crafting iron" on top, rub it in," and "Xu Yisheng sucks it under the slightest sentences", pig iron, "cooking" iron, can be kept at a certain distance, and can be poured in a controlled manner. According to Mr. Zhou Zhihong's investigation in 1938, Zhou Zhihong: "Creative Achievements in Early Steel Smelting Technology in China", "Science Bulletin" February 1956. Chongqing Beibei Sugang also adopted a similar operation. It did not require sealing mud, applying mud, or covering broken grass shoes, and the process was simplified.

These three operations reflect the process of continuous development of steel filling technology and the gradual deepening of people's understanding.

(III) The process principle of steel filling He Tangkun: "A Preliminary Discussion on Steelmaking Technology in Ancient China" and "Several Issues on Steel Pourging", see "Collected History of Science and Technology" Volume 14 (1985), Volume 15 (1989), Shanghai Science and Technology Publishing House.

Because steel filling uses pig iron and "cracker iron" as raw materials, some scholars believe that it is a process that uses pig iron to carburize into cracked iron, which is a misunderstanding. The main purpose of steel filling smelting is not to adjust the carbon content, but to eliminate inclusions. In fact, the hundreds of refining methods and the refining methods were invented on the basis of stir-frying steel to further remove inclusions. The basis is:

(1) As mentioned earlier, the carbon content of "cracker iron" in ancient times was equivalent to that of wrought iron. Because the poured steel uses "cracker iron" as the raw material, after the pouring, its carbon content may increase, decrease, or change little.

(2) In 1938, Mr. Zhou Zhihong conducted a composition analysis on the raw materials and products of the Sugang Workshop in Beibei, Chongqing, and the results are listed as Table 2-6.

It can be seen that the carbon content of its products is the same as the carbon content of the raw material "crystalline iron". The main difference between them is: the silicon, manganese, phosphorus and sulfur content in the finished steel is slightly lower than that of the raw material "crystalline iron". This is obviously because of the inclusion. In other places, the carbon content of its Suste Steel products may also be higher or lower than the carbon content of the raw material "crystalline iron", but this is not the main purpose of ingestion.

Steel pouring is an outstanding creation of ancient Chinese metallurgical technology. It uses the characteristics of high carbon content of pig iron and high oxidation and inclusions of "cracker iron" to oxidize silicon, manganese, and carbon in pig iron, causing a fierce "boiling" and achieving the purpose of removing inclusions. Although the operation is simple, the effect is very obvious. This is the highest achievement achieved in ancient human steelmaking technology. Volume 5 of Tang Shunzhi's "Wu Bian Zhang" said: "This steel is combined with two iron,

The hands of the two classics are combined into one, with less sand, soil, dregs, so it is easy to train." Chen Chunhua said that "the dregs were gone at the time", which is without exaggeration. John Day (John Day) praised steel as "the predecessor of the method of open furnaces in later generations" in his book "Use of Prehistoric Steel", which is not an exaggeration. It is quoted from Li Hengde's "Iron and Steel Metallurgical Technology in Chinese History", "Natural Science" Volume 1, No. 7, December 1951.

5. Crucible Steel

There is only one example of steel in ancient my country's crucible steel, He Tangkun et al.: "Preliminary Study on Crucible Adhesive Steel in Luoyang", "Research on History of Natural Sciences" No. 1, 1985. But it is very conclusive. Crucible steel was undoubtedly smelted in the Han Dynasty of my country.

In 1979, the Luoyang Cultural Relics Team excavated a batch of Han tombs in the Geely Working Area on the north bank of the Yellow River. One of them was unearthed 11 crucibles. The crucibles are all straight and cylindrical, with a slightly rolled outer edge, a round bottom, and an outer diameter of generally 14-15 cm, an outer height of 35-36 cm, and a wall thickness of 2 cm. Both the inner and outer walls are burnt, with coal blocks, slags and other substances on the surface, and the inner surface is relatively smooth, and a thin layer of iron slag is stuck in some places.

.A steel block is adhered to the middle section of the inner wall of one of the crucibles. The steel blocks are halberd-shaped, with a yellow-brown surface, 10 cm long, 15 cm wide and 0.4 cm thick. The accompanying objects are five Wuzhu coins, which are equivalent to the II and III types (mid-West Han Dynasty) of the "Mancheng Han Tomb Excavation Report". After the crucible thermal light-release test, it dates from 1832-147. The burial age is generally determined from the middle and late Western Han Dynasty to the middle Eastern Han Dynasty.

After chemical analysis, the carbon content of the steel block is 1.21%, which is an overeutically eutectic high-carbon steel. The results of the component analysis of scanning electron microscope (energy spectrum) are: iron 98.637%, phosphorus 0.277%, sulfur 0.584%, silicon 0.117%, aluminum 0.383%. It can be seen that it contains phosphorus and sulfur is relatively high. From the metallographic analysis, the metal matrix is ​​pearlite, and there are many mesh cementites, phosphorus eutectics and oxides distributed on the intergranular boundary. The carbon distribution is relatively uniform, basically is equiaxed, and no obvious columnar crystals are seen. The phosphorus eutectics are distributed on the intergranular boundary in irregular star shapes. After scanning electron microscope analysis, the eutectic region contains 9%-12%. No matter whether the metal grains or non-metallic inclusions, there is no stretching or crushing, indicating that the steel block has not undergone any pressure processing after condensation.

After analysis, the components of the crucible are: SiO243.57%, Al2O337.28%, Fe2O33.46%, K2O0.63%, Na2O0.26%, C13.66%. It can be seen that its alumina amount and carbon amount are relatively high, which is obviously a purpose-built. The advantage is that it has high refractory resistance and good thermal stability. After measurement, the refractory resistance of the crucible is 1580-1610℃. According to the Fe-C balance diagram and taking into account the influence of other inclusion elements, the temperature of the complete melting of the crucible attached steel is about 1470℃, so the refractory resistance of the crucible can meet the smelting requirements. This also reflects the superb refractory material technology in ancient my country.

There is no more information available for the smelting process of crucible attached steel. We speculate that it is likely to be a direct smelting, that is, iron ore as raw material, charcoal and coal as reducing agent and carburizing agent, and directly reducing carburizing in the crucible. Generally speaking, the products obtained in this way should be pig iron, but properly controlled, steel can also be obtained. It is said that the crucible steel in ancient India was obtained in this way. However, most of the crucible steel in ancient India did not reach liquid state, but a semi-liquid state with glue melting. The baked products are often a solid block with extremely uneven structure and composition. Luoyang crucible steel was fully melted. In the West, liquid crucible steel only appeared in 1740, and my country refined liquid crucible steel in the Han Dynasty, which is really commendable.
Chapter completed!