There are a lot of firewood piled up on both sides of the centipede stove, and there is a house outside the ground, and the flame at the mouth of the furnace can be spewed out more than a foot long.

"It was a stove just now, and now it's lighter. ”

Tianyou did not operate it by himself all the time, but handed over the bellows to Kuroko to operate. Although it's the first time I've seen this thing, the bellows are really not technical, and the sunspot will be able to take a look.

The flame is indeed much smaller after slowing down, but the temperature inside is already very high. The old horse who helped was still standing at the mouth of the stove according to his previous habit, wrapping the door handle with a damp cloth soaked in water, but as soon as he opened the door of the stove, a heat wave immediately hit his face, and his face and chest instantly felt hot and unbearable, so he hurriedly ran to the water tank and scooped up the scoop of water and splashed his face to feel better. When he turned around, Kuroko found that his eyebrows and beard were already burnt, and they were still smoking after being stained with water.

"Uncle Ma, be careful, the temperature of the furnace is too high, it is better to stand on the side of the furnace mouth. After Tianyou finished speaking, he reminded the sunspot, "Brother Hei, don't pull it yet, we want to fill it." ”

As soon as Kuroko heard that he didn't need to pull the bellows for the time being, he and the old horse began to help with the filling.

The development of the metal smelting process in this world is a little off, and it is generally similar to the ancient smelting technology that Tianyou knew in his previous life, and it is very backward in terms of basic smelting, but because there are some special smelting methods that use the attributes of aura, the overall level is basically the same as the metal smelting level of the Song Dynasty that Tianyou understands. Of course, there will be some very few super weapons among them, but those are mainly the effects of aura, magic circles and the like, and they have nothing to do with metal smelting technology.

In ironmaking, crucibles are still used to heat the iron ore and then pour out the liquefied molten iron, leaving iron slag. Of course, there are a lot of impurities in the molten iron produced by this method, which is not even pig iron, and needs further treatment.

Although Tianyou has studied knife manufacturing with Japanese knife casting masters and German metal experts, due to the technology of this era, he will definitely not be able to make those super-quality special materials in his previous life. However, there is no way to do it without equipment, although it can't make a super metal, but Tianyou can make a super strong alloy that the local aborigines can't think of.

The iron ore was put into the No. 2 furnace door to preheat, and Tianyou began to get busy with Lao Ma and Kuroko again.

Under the command of Tianyou, open the door at the end of the centipede furnace and put in a large amount of firewood. This step was completely incomprehensible to the old horse and Kuroko, because the wood at the end could not be lit at all. The air intake of the centipede furnace is only at the very front, and there is no oxygen left after the air passes through the three-stage combustion chamber, so even if the firewood is put in the back door, it will not be lit at all.

Although they didn't understand Tianyou's purpose for doing this, Kuroko and the others felt that he must have a good intention, so they didn't say anything, anyway, they did whatever Tianyou said.

In fact, what Tianyou is doing is very simple, he is burning charcoal. The combustion efficiency of firewood is actually very bad, and although there are many reasons why the furnace temperature cannot go up, firewood itself is also a big problem.

The front combustion chamber of the centipede furnace will run out of oxygen in the air, creating a low-oxygen or oxygen-free environment, while the furnace still retains a high temperature. This state is actually how the coke oven works. So Tianyou would be so surprised when he saw the centipede furnace before, because in addition to completing the work of smelting, calcining, annealing, and tempering, the centipede furnace can actually make a cameo appearance as a coke oven. The only pity is that there is no way to recover coke oven gas.

After putting the firewood, Tianyou and Lao Ma closed all the furnace doors together, and the sunspot began to pull the bellows, this time because the furnace door was tightly sealed, but there was no need to worry about igniting the house again, and under the guidance of Tianyou, the speed of the sunspot was not very fast, just ensure that the fire is appropriate. To be honest, even if there is more pump air for firewood, the temperature is not high, and the subsequent steps depend on the charcoal.

Smelting iron ore is a slow process, especially if the equipment is not good enough. A few hours later, Kuroko and Tianyou had already exchanged two times, and after the charcoal and firewood in the furnace had been exchanged several times, the iron ore finally melted into molten iron completely.

In this process, Tianyou has already stockpiled enough charcoal, and the next one will depend on this charcoal.

Open the furnace door, remove the red-hot iron juice, then empty the wood that has not been completely burned, and fill the furnace with the burned charcoal. He took the wrought iron that Tianyou had found in his free time, put it in a new crucible, poured the previously burned iron liquid on top of the wrought iron, and then sent it into the furnace again.

Seeing this step, if you are a knowledgeable person, you should understand. God bless this is in the steel filling. The steel filling method was invented very early in ancient China, which is characterized by simple operation and can produce cheap steel in large quantities. Tianyou doesn't have the right equipment here, so he can only make steel in this primitive way, but that's not all he has to do.

After resealing the furnace door, the heat began, and this time the flame was noticeably different. Coke burns at a significantly higher temperature than firewood, as can be seen from the color of the flame. The pig iron and wrought iron in the furnace melt together, carburize each other, and then turn into molten steel, and at the same time, because the furnace temperature rises very exaggeratedly, impurities are further removed, but that's not all.

Tianyou crushed the best carbonized part of the charcoal that was worth it before into toner powder, added it to the molten steel, and then continued to burn, and then found some fine sand. This was supposed to be the material needed to make a casting mold, but it was also thrown into the molten steel.

Heizi and Lao Ma felt that they couldn't understand what Tianyou was doing at all, although Tianyou would explain after they asked, but they didn't understand what sulfurization, carbon adjustment, and silicon addition were, and finally didn't ask at all, anyway, just look at the finished product in the end.

Kuroko was busy until the early hours of the morning and fell asleep leaning on a pile of firewood, and then even the old horse fell asleep on the bench for resting, anyway, there was a big stove next to it, but it was not cold at all.

Although Tianyou is a little busy, he is more efficient, because he doesn't have to explain this and that to Kuroko, which saves a lot of time.

The original molten steel had been divided into two crucibles, and the amount was not large. Originally, he didn't have much to do, and he didn't need so many materials.

The molten steel in the two crucibles was treated in different ways after the carbon was adjusted, and some strange powders were added to each of them. These powders were collected by Tianyou before, and they were brought with them when they came out of Qingyuan Village. He originally planned to use the powder to make a new strongbow in Taoyuan City, but the plan couldn't keep up with the change, and he ended up here, but fortunately, the things were still used.

It took Tianyou about six years to collect these powders, and I didn't deliberately look for them, but I just put them away when I saw them.

The two powders added to crucible No. 1 are tungsten and osmium. Needless to say, tungsten is a very common metal in modern industry, which can greatly improve the hardness and high temperature resistance properties of steel. Another metal, osmium, is less well-known than tungsten, but it is not a small thing.

Tianyou had inadvertently discovered an iridium and platinum mixed gold mine in Qingyuan Mountain, and he didn't have the ability to explore the reserves or anything, so he knew that the mineral deposits were very shallow, almost all of them were open-pit mines. It's a pity that it's useless to dig it up, no one here recognizes it at all, so he can only pick up some casually and play with it himself, but the discovery of osmium in it is really a windfall.

Although the elemental nature of osmium is not very useful, this thing can be mixed in steel to synthesize super-hard metal, and the armor-piercing arrow used by Tianyou before can easily penetrate even the protective aura of the innate master, relying on the incomparably sharp arrow, and that arrow is made of iridium sharp arrows and super-hard metal doped with osmium.

The steel in the first crucible is used to make armor-piercing arrows, so it needs to be hard, and the second crucible is the material for the new bow, so the ingredients added are also different. Tianyou added manganese and grit to it in order to increase the content of manganese and silicon.

In fact, the molten steel in the No. 2 crucible is finally made into spring steel, but now it is only molten steel, and it is still far from spring steel.

Smelting, arranging the salt brine for quenching, and making molds from clay, Tianyou worked until dawn to finally get all the work done, and when Kuroko and Lao Ma woke up to a jingling knock, they found that the door at the end of the centipede furnace was open, and there were a large number of strange-shaped metal parts on the pallet inside.

Not far away, there was a sudden sound of percussion again, Kuroko and the old horse hurriedly got up and ran over, just in time to see Tianyou was using pliers to hold a steel bar on the anvil and repeatedly knock it, and the oil tank next to it was full of a turbid liquid that had never been seen before, and there were dozens of completed arrows soaked in it.

"This ...... You did it all alone?" Kuroko and Lao Ma asked as they looked at Tianyou in disbelief. Even if you don't count the strange things in the stove, these arrows alone will require them to work for at least two days and two nights, but Tianyou actually made them all in less than one night. Of course, there are some reasons for this, such as the increase in furnace temperature speeding up the smelting process, but even then the speed is too frightening.