Li Qiu, the old shopkeeper sent by the old lady from his side to help Li Jing manage the steel industry, came to Li Jing. Li Qiu spent most of his life as a shopkeeper in the Suzhou Iron and Steel Refining Workshop, and was kicked out because of the struggle between the proprietors' houses, and defected to the Li family for more than ten years.

"Young master, why don't you smelt the pig iron that has accumulated a lot in the past two days into steel, but instead burn the pig iron ingots red, and beat them with that what is called a hydraulic forging hammer."

"The blast furnace can only smelt raw iron, and steelmaking requires crucibles, converters or open hearths, which are too difficult, I don't have time to get them, I'm going to the capital and Liaodong soon, I don't have time to get them."

"Oh, my young master, where does steelmaking need to be so troublesome. Although the old man doesn't know what you said, the crucible, the open hearth or something, but the blast furnace you designed, young master, has never seen such a big and efficient one in his life. I guess your steelmaking method is even better, but now you can use the existing methods to make steel, and it doesn't cost too much. This time, many of the masters sent by the old lady will fill the steel method. ”

"I know the steel filling method, which is to use a blast furnace, lay wrought iron on the bottom, and pig iron on the top, after heating, the pig iron melts first, and the melted pig iron is poured on the wrought iron to form steel juice together. Then a steel opening is made in the place between the pig iron and wrought iron, and what flows out is the steel. But where did wrought iron come from? If we use the steel filling method, we need a lot of wrought iron, how can we make this?"

"Oh, my young master, you asked the old man earlier, wrought iron is the best. If wrought iron is made, the pig iron flows out and is connected within a few feet of a few inches, and a pond is built, which is blocked by four short walls, and its iron flows into the pond. Several people hold willow sticks and stand on the wall in rows, first dry them with dirty mud, sift them like noodles, and one person scatters them quickly, and everyone stirs willow sticks quickly, and immediately stirs the mature iron. Every time the willow stick is fried, it is burned two or three inches, and then it is even more. When it is slightly cold, wrought iron is obtained. ”

"What, it's okay like this, the pig iron juice flowing directly from the blast furnace can be stirred quickly with a willow stick." Li Jing thought for a while, and suddenly understood the principle. It turns out that the local method has such a big advantage.

What Li Qiu said is actually the process of oxidation and decarburization of pig iron. The main point of operation is to use oxygen in the air to oxidize silicon, manganese, and carbon in pig iron in a liquid and semi-liquid state. Stir the metal quickly throughout the process. Finally, after cooling, it is the steel that forms a clump.

Li Jing used a water hammer to beat out 100 steel, which was obviously not as good as the "steel filling" method that Li Qiu said. First of all, the method of "tempering and refining" is particularly labor-intensive and time-consuming, and the metal yield is low; The losses are too great. Secondly, the composition is not easy to control, and the slag removal ability is not strong enough. The strong slag removal ability of steel filling is mainly related to its own process characteristics, pig iron contains higher silicon, manganese and carbon, lower melting point, and more oxidation inclusions in "wrought iron" material; At the time of refining, the chemical reaction was very intense. Some of the iron oxides in "wrought iron" will be reduced by silicon, manganese, and carbon to improve the metal yield. Many bubbles are also generated during this process, and some of the oxides are carried out and flowed away, resulting in a less inclusional steel mass.

Li Jing touched his chin, thinking that such words would be simple. If it is so easy to get steel with different properties, simply make the rolling mill as well. Directly pressed into sheets. With water hammer, you can make molds, press them into plate armor, helmets, and so on.

Li Qiu continued: "The so-called Sugang is to beat wrought iron into thin slices, and then pour it with pig iron juice to form steel, which is more efficient than the Song and Yuan dynasties when wrought iron was beaten into wire rods and poured with pig iron juice. ”

Li Jing was inspired, and even thought one step further, the redox decarburization reduction of pig iron is not done instantaneously, he needs to keep stirring for a long time. If the decarburization is not carried out to the end, and the molten iron is stabilized and cooled down at a certain level of carbon content, then this is a variety of finished products of low-carbon steel or even high-carbon steel. There is no need for the back steel filling method to tap the steel. As for the degree of stirring, the amount of carbon content must have external manifestations, such as the color of the molten steel, the color of the flame, the temperature, the slag situation, etc., there must be a way to directly observe.

Li Jing opened the light curtain, and the customer service sister appeared. Li Jing asked, "Can you scan molten steel with different properties?" I want to see the external characteristics of steel with different carbon contents. ”

"I understand what you mean, this is simple, charge you ten coins, I will scan it directly, and then publish a book for you, you can judge the carbon content according to the external characteristics of the molten steel, and you can make different grades of steel."

Li Jing immediately took Li Qiu and a group of masters to the bottom of a blast furnace, let Li Qiu command, and temporarily built a mixing pool. A group of guys with willow sticks are ready. With a shout from the stove, the iron was out. A stream of red pig iron juice was poured into the mixing pool, and seeing that the pool was about to be full, the chief Sugang master shouted loudly, started stirring, and immediately the skilled guys began to stir.

Li Jing said: "This pool is for experiments, don't stop me to stir, don't be afraid of waste." ”

At the same time, the light curtain is turned on, and the light curtain starts scanning the whole process, and various numbers are constantly displayed on the screen. and a variety of different metal contents. Soon the pool of pig iron was stirred into wrought iron, which was close to the state of pure iron.

The customer service sister said: "Okay, the data is scanned, and I will give you a book in an hour to explain the optimized process and process in detail." With the naked eye, you can judge a variety of steels with carbon content. You need that kind of steel, just stop stirring when it matters. ”

This pool has already become mature iron, so it can only be beaten into thin slices to fill steel according to Li Qiu's method. Li Jing looked at everyone and asked, "Is there a master who understands casting?" ”

Immediately, more than a dozen masters came out of the crowd, bowed down and said: "Back to Gongzi's words, we all know the casting."

Li Jing saw that so many people knew how to cast, so he was a little surprised, so he directly took out rice paper and drew on the table, all of which were rolling pin-like rollers of the same length but different thicknesses. There are also some cast iron brackets. As well as some iron molds for stamping plate armor. The crowd looked at it for a while and began to discuss.