Another day, the craftsman followed the military order and began to build tools for himself in full swing.

When I first started making tools, I discovered that there were missing piers for striking iron, iron pots for scooping iron, pliers, hammers, chisels and files.

Everyone only focused on striking for themselves. The anvil shared by the blacksmith was large and heavy, but no one wanted to strike.

A large group of people were crowding around with only three or five anvils waiting to be used, but no one thought about knocking out the anvils first. The captain of the blacksmith couldn't stand it any longer, and shouted at everyone, asking everyone to build them first.

As for the anvil, three people should make one anvil first and then hit the others, so that everyone can coordinate well.

To put it simply, an anvil is just a pier for making iron. As long as it is strong enough and flat enough to be the size of a basin, making an anvil is not difficult, but it requires a lot of iron.

When another furnace of molten iron came out, the craftsmen were waiting to get the iron anvil. At this time, Li Mengxi and Guan Yu came together.

Seeing the two people coming, I thought they were going to build something again, so the craftsman captain came up to meet them.

"No need," Li Mengxi said, "You are busy."

With that said, he and Guan Yu walked to Tiequ.

Guan Yu took the iron cauldron from the blacksmith's hand and scooped out half of the molten iron from the iron pool. Then he scooped up the iron and walked to an anvil, occupying it.

The craftsmen wondered, could General Guan also forge iron?

Guan Yu was not good at blacksmithing, but he could still break the iron into pieces.

As the craftsmen watched in confusion, Guan Yu held a clamp in one hand and a small hammer in the other, banging it. It was obvious that Guan Yu was not good at forging and was clumsy in exerting force.

The captain of the blacksmith came over again and said that if he wanted to hit something, he could ask them to hit him.

Guan Yu waved his hand and refused the blacksmiths' help.

Just like when papermaking was being made, because Li Mengxi made the underlying principles of papermaking so clear and explained it so clearly that Guan Yu understood it too well, so when papermaking was being made, Guan Yu couldn't help but cook the pulp for several nights.

, just to find out.

Guan Yu was more interested in wrought iron, which was closely related to the magic weapon, so he tried it himself.

Guan Yu was banging his hammer against the iron, while Li Mengxi was watching from the side with his arms folded.

Although Guan Yu was not familiar with blacksmithing, he was very strong, and he never failed to hit the iron with his hammer.

According to the iron forging process, there are two ways to forge pig iron into steel. One is to beat half of the pig iron and decarburize it directly into steel; the other is to beat the pig iron completely, and then slowly carburize the pig iron after it is made into mature iron.

Of the two methods, the former has fewer procedures, but has a low success rate and requires high experience, while the latter, although it has many procedures, is easy to operate and has a higher success rate.

Most forged steel knives are first forged into mature iron and then carburized and forged, which is equal to two hundred rounds of forging process, and the workload is extremely long.

According to the method of directly forging and decarburizing into steel, Guan Yu stopped halfway through the process. He looked up at Li Mengxi who was standing next to him and asked doubtfully, "Xi'er, you are talking about this pig iron, how did he get the charcoal out?

Understand?"

Li Mengxi thought for a while and said, "Charcoal is flammable when exposed to fire, and combustion requires gas. Therefore, the decarburization of pig iron is probably at high temperature and in full contact with gas, so that the charcoal burns into smoke and escapes, and then the charcoal is removed.

Already."

"Therefore, when forging and decarburizing pig iron, you should heat it more to keep the iron hot. The hotter, the better. The hotter the iron, the more intense the charring."

"Furthermore, when hammer forging pig iron, you should hammer it from thinner to larger. The thinner it is, the larger the contact surface with air is, and the faster the charcoal will burn."

"Probably both."

Guan Yu nodded, and when forging pig iron, one needs to be hot, and the other needs to be thin, that's how it is.

Guan Yu looked at the iron he had struck, and saw that it had become a lump, and the iron had become cold after being struck for too long. This was not possible.

Guan Yu picked up the iron with pliers and put it on the fire to heat again.

At this time, Li Mengxi frowned and was thinking about another question. Iron is heated using charcoal fire. When the charcoal fire heats the iron, it can burn away the charcoal in the iron, but at the same time, charcoal will also seep into the iron. What effect does the charcoal fire have on the iron?

Does iron carburize or decarburize faster?

do not know.

Anyway, charcoal fire can both decarburize and carburize.

When pig iron is burned for a period of time, the charcoal content will decrease. At the same time, when wrought iron is burned for a period of time, the charcoal content will increase.

If we can try to improve the flame, instead of using charcoal flames and heating with oxygen or other substances that do not contain carbon, the forging will be much clearer.

However, in the late Eastern Han Dynasty, it was almost impossible to use other heat sources for forging except charcoal fire.

If the technical process of pig iron - wrought iron - carburizing into steel is used to forge steel, it is known that the temperature for forging pig iron should be higher to facilitate rapid decarburization, but wrought iron carburization, on the contrary, aims to make the carbon

Penetrating into iron, then, in order to reduce the self-consumption of charcoal, when wrought iron is carburized, the wrought iron temperature can be lower, and the charcoal fire temperature can also be lower, so that the carburization speed can be greater than the charcoal burning speed.

That is to say, during the forging process, two kinds of fire are used, one is a high temperature and intense fire, and the other is a small charcoal fire with a pile of charcoal on top and a small fire underneath.

When making pig iron, high temperature and intense fire are used to heat the pig iron to make the temperature of the pig iron as high as possible. When carburizing wrought iron, a charcoal fire with multiple charcoals and a small fire is used to carburize it at low temperature and efficiently.

Seeing that the blacksmiths only have one kind of furnace, I don’t know if this is because the blacksmiths’ tools are imperfect or because they simply don’t have the awareness to deliberately carry out dual-fire forging.

According to Li Mengxi, during the subsequent forging process, Guan Yu made the iron as thin as possible and beat it into a thin iron sheet, and then heated it on the fire frequently.

When Li Mengxi saw this scene, he immediately felt that something was wrong.

area, high-temperature pig iron burns with oxygen in the air, so the thinner it is, the more conducive to decarburization. However, when it is taken back to the fire and burned, if it is still a thin iron sheet at this time, the larger the area in the air, the easier it will be to decarburize.

Carbon, in the same way, is easily infiltrated when heated in a fire.

That is, it affects decarbonization efficiency.

Therefore, after improving the technology, it became, [When forging pig iron, forge it as thinly as possible, but before reheating, reduce the surface area of ​​the pig iron as much as possible and make it form a ball.]

To put it simply, after the iron is heated in the iron furnace, it is beaten into thin slices on the anvil, either forward or backward, into various thin slices. When the iron is cool and ready to be heated, the iron slices are beaten into compact pieces.

A lump to reduce the penetration of carbon as much as possible.

On the other hand, if it is the carburizing step of wrought iron, spread it as thinly as possible when heating, and beat it into a ball when forging in the air to minimize the area exposed to the air.

This advancement and retreat is efficiency and quality.

Guan Yu was halfway through striking the iron when he stopped and asked Li Mengxi to come over and see if the iron had become steel.

How could Li Mengxi tell whether it was steel? He could also tell if it was wrought iron. Wrought iron was very soft and could be pinched and deformed with bare hands.

The iron pieces on the iron piers were lightly knocked a few times with a hammer, and there was a slight tinkling sound, but they were not soft at all.

"It may be steel, or it may be pig iron, I don't know." Li Mengxi answered.

Speaking of which, is there a clear, intuitive and easy to quantify method to judge the carbon content of iron? Experienced blacksmiths can judge the quality of iron based on the sound of the iron piece being struck, but judging by the sound relies too much on experience.

As for someone who can taste it by licking it, that's even harder to learn.

After much deliberation, Li Mengxi thought that the color and charcoal itself were black, so the higher the carbon content of iron charcoal, the heavier the heat and the darker the color. The color is extremely intuitive.

Or you can make a hundred steel bars first, and then select the one with the best quality as a color comparison card. In this way, every time you make a piece of iron, use the steel bars to compare the colors. The closer the color is, the higher the quality.
Chapter completed!