It turned out that Li Xian had been working day and night with Xuan Zheng and a fourth-order master these days, just to find an effective way to produce special knife steel from graphite crucibles.

In human history, the method of melting metal into molten steel from graphite clay crucibles was first applied by the Englishman Hunzman () in 1742.

The specific method is to cut the carburized iron into small pieces and place them in a closed clay crucible, heat them outside the crucible, and the iron will continue to absorb the carbon in the graphite and melt it into high-carbon molten steel, which will be cast into small ingots and then forged into the desired shape.

When the steel is melted in the crucible, the graphitic carbon can also act as a reducing agent, and the reduction reaction occurs.

In this process, the oxygen in the steel can be removed, and various inclusions can also be removed from the liquid steel, so the quality of the steel is better than that of general metal materials, which can be used to make tools for processing metal materials.

If Li Xian wants to improve his industrial capacity and improve the level of military production, he needs the support of a large number of machine tools.

General machine tools are not enough, the real key machine tools need special steel materials with particularly excellent material properties, and the tool steel required for cutting is indispensable.

Originally, Li Xian could directly import advanced machine tools from Europe, as well as the tools consumed in the production process, but he knew that this key material completely relied on imports, and there would be endless troubles in the future, so it was inevitable that he would master the advanced graphite crucible production technology and realize the production process of this tool steel and special steel.

However, such a high-level technology is not something that can be quickly obtained knowing that graphite crucibles can be used to make molten steel, or even being reproduced by obtaining relevant books.

Li Xian obtained a large number of books on graphite crucible steelmaking through various channels, and even purchased professional finished graphite crucibles and the raw materials used to make crucibles, and led the blacksmiths he recruited from Foshan to conduct many experiments, but it was not enough to master the technology immediately.

In general time-traveling books, the protagonist often goes back to ancient times, then finds graphite raw materials, and then directs local blacksmiths to produce, and soon obtains a large amount of high-quality steel, which is simply impossible in reality, and this is too much to underestimate the difficulty of realizing such an epoch-making steelmaking technology.

There are generally three technical difficulties involved in graphite crucible steelmaking technology, the first is to process the fuel required for steelmaking to obtain sufficient furnace temperature, the second is to have a good enough blast equipment, and the last is to produce a usable graphite crucible.

In terms of technical difficulty, the difficulty of blower equipment is higher than that of fuel treatment technology, and the production method of graphite crucible is much higher than that of the previous two.

According to Li Xian's estimate, even if he has enough detailed technical information, a large number of finished products as models, and a large number of excellent craftsmen at hand, it will take three or five years to imitate a graphite crucible that can withstand high temperatures, and it will take even longer to master the entire set of steelmaking technology.

In Li Xian's world, Japan began to explore liquid steelmaking technology in the 19th century, and it took more than three years to master open-hearth steelmaking technology with a large number of steelmaking industry professors and detailed information provided by the great powers.

The graphite crucible steelmaking technology looks smaller than the open-hearth steelmaking technology, but the actual difficulty has increased.

Under normal circumstances, if Li Xian wants to master the graphite crucible steelmaking technology, he must introduce coal suitable for making metallurgical coke from Nanyang, and then learn the technology of making metallurgical coke from coal;

Then, he studied the production of large-scale hydraulic blowers or steam engine blowers, obtained complete steelmaking furnace design drawings, and obtained complex and difficult exhaust equipment design and installation technology;

After that, he played with graphite materials, tried different graphite ore materials, refractory clay, kaolin, etc., according to the instructions of technical materials, and finally learned to make graphite crucibles that can withstand high temperatures by chance.

If you are lucky, you can learn it in three or five years, and if you are unlucky, you can learn it for more than ten years.

Fortunately, Li Xian himself is a martial artist who has mastered the Dao Species, and he has met an innate master like Xuan Zheng and a large number of fourth-order great master-level masters, so there is no need to completely follow the ordinary route to study the crucible steelmaking technology, and there are many shortcuts to choose from.

The method Li Xian chose was to let Xuan Zheng use the fire system Dao method to increase the temperature of the flame when he was burning the fire, and then let several fourth-order great masters who were proficient in the earth system Dao method use the earth system true qi to protect the crucible so that it would not disintegrate in the high temperature.

As for the production of graphite crucibles, which should be the most difficult, it is not difficult to achieve, that is, to use true qi to put into the finished crucible and explore its raw material processing methods and physical properties.

Graphite crucible is not actually made of mud kneaded on the line, the production process is shaped and then put into a special kiln for firing, after molding, there is a layer of glaze on it, strong and durable, in this sense, graphite crucible is actually a special material porcelain.

Fortunately, China's ceramic production technology is still the most advanced in this era, Li Xian specially recruited the best ceramic workers to come in, and also gave the Chaos Dao Seed to improve the imitation ability of these workers, and then asked Xuan Zheng and the fourth-order great masters to follow and study the production technology of graphite crucibles, and finally overcame this difficulty in a short time.

Therefore, the research and development of graphite crucible steelmaking technology on Li Xian's side is actually reversed, that is, to use the abilities of martial arts masters to use low-quality fuel and crucibles to produce molten steel, and in the process master key parameters such as calcination temperature, time, and raw material ratio, and then think about this method to reduce the participation of masters, and use machines and ordinary means to achieve the effect that originally required masters.

It is also for this reason that Li Xian put forward the concept of universalization, that is, to let the masters refine the product first, and then reproduce it by ordinary means.

Of course, there is also a huge limitation of this method, that is, in the main world, the masters cannot sense and drive the innate elements, so they cannot use this method, and can only be carried out in the blessed land.

Fortunately, Sanyuanguan sits on the blessed land of Sanyuan, and Li Xian puts the Steelmaking Research Institute in the blessed land, and he can start the research and development of this steelmaking black technology.

With the help of the abilities of the martial artists, refining molten steel is not easy to do, Li Xian has an innate master like Xuan Zheng on his side, and several fourth-order great masters to help, but the ratio of carburized iron bars alone has to be confirmed by many experiments, and it has been smelted for more than five hundred furnaces before the first furnace of molten steel is smelted, and then after many explorations to produce the first furnace of qualified knife steel, the materials and manpower consumed in the middle are astronomical.

With this experience, after many attempts, Li Xian also figured out the formula and production method of special performance steel in practice, and then replaced Xuanzheng's temperature control work with coke, charcoal and steam engine blowers, and then improved the high temperature resistance of graphite crucibles, so as to realize the universalization of molten steel production, that is to say, relying on ordinary craftsmen can also produce various tool steels.

With a variety of tool steels, Li Xian can try to imitate all kinds of advanced machine tools, and then use machine tools to produce steam engines to increase production capacity, and can also greatly improve the current military production capacity, can produce artillery, rifled guns and smoothbore guns by himself, etc., without the need to import everything or seize it in battle.

Today, after refining this furnace of molten steel, even if Li Xian has mastered a new knife steel formula and production process, it is of great significance.