The heating temperature required for quenching is different from the previous two steps. According to Li Mengxi's understanding, the principle of quenching is to heat to a high temperature and suddenly shrink. Iron rapidly forms crystals during the sudden cold shrinkage, and the hardness is obtained due to the change in the crystals.

.

Therefore, naturally the higher the temperature, the greater the difference between the temperature and the cold water, the more severe the sudden cooling, and the harder the crystal is.

It can be inferred from this that the quenching effects of cold and hot water are different, and the quenching effects of high-temperature iron and medium-temperature iron are also different.

Li Mengxi was still thinking about things, and Guan Yu quickly put the knife on the fire to heat it. The edge of the knife covered with soil was burnt white, and the temperature was definitely not low.

When the quenching began, Guan Yu held the knife with iron pliers and plunged it into the cold water tank. The hot blade made a sizzling sound when it encountered the cold water.

Yesterday, when the blacksmith was forging a knife, Guan Yu also watched the whole process. When the blacksmith was quenching the knife, he briefly dipped it in water several times. Guan Yu followed suit and dipped it in water several times.

The knife is originally small, but the palm is a little longer. After being continuously dipped in water, the temperature has dropped to the point where it can be held with bare hands.

I tried the method of covering the blade with soil and burning it as mentioned by Li Mengxi, and the quenching was completed. However, when Guan Yu pulled away the earth crust on the knife and took a look, Guan Yu suddenly frowned.

For some reason, after the knife was tempered, it was not only bent, but also had several cracks in the blade.

Showed it to Li Mengxi, Li Mengxi saw at a glance that the knife was almost useless.

Go to the knifemaker immediately and ask.

The swordsmith took the broken sword, took a look at it, and directly gave the reason, "It was too hot during quenching, and it will crack when exposed to water."

It turns out that the temperature was too high.

The knife maker said that it can be repaired, and it can be repaired by reheating and hammering it, but it is not very strong anymore.

I was just planning to make a meat cleaver. If it's not strong, it won't be strong. It's not a big problem.

After that, the knifesmith spent a short time red-hot forging the knife again, and repeated the annealing and normalizing process. When it was re-quenched, Li Mengxi watched carefully. He saw that the blacksmith had heated the knife to a red-hot state, not

White hot state.

The quenching temperature seems to be extremely critical. If you are not careful, the knife will be bent and cracked. No matter how good the steel is, if it is full of cracks, it will be useless.

The quenching was not very smooth. It may be a problem with the blade. The blade may be too thin. The knife maker quenched it himself. After quenching once, the knife was still bent.

After that, it was quenched three times in a row, and it was bent every time. Finally, the fourth time, the quenching was successful.

Yesterday it was quenched once, but today it failed repeatedly. Every time quenching failed, it had to be reheated and forged, which would take longer.

According to the swordsmith, the quenching temperature is difficult to control. It is normal if the quenching is damaged. It is normal to quench it three to five times. It is not unusual to fail after quenching it seven or eight times.

The information has changed. I originally thought that the most troublesome part of the entire forging process was the forging. The other processes did not take long. It turned out that the success rate of quenching was not high and it was also very labor-intensive.

Quenching was so difficult that Li Mengxi did not have the confidence to test the effects of urine quenching and grease quenching. He told the swordsmith that it is said that quenching with horse urine and butter can make the sword sharper. The question is whether to use horse urine or butter first.

I don't know the difference between the quenching temperature and water quenching.

Li Mengxi said to the knife maker, "You can try it yourself and see if this is a good method or a misinformation."

The knife maker heard Li Mengxi tell him a secret method. Li Mengxi's words were very meaningful, and he said he had a nose and eyes, so the knife maker secretly wrote down this method.

Skill is the cost of living. If you occasionally get a secret skill, a swordsmith with rich forging experience will definitely try it secretly. Put the experience there and let the professionals test it, which is much more efficient than Li Mengxi's random testing.

The subsequent tempering is still done by the knifemaker.

Li Mengxi told the knife maker about the idea of ​​using an earth kiln for tempering, and asked if it was possible to use an earth kiln for tempering on a large scale. The knife maker was stunned for a moment, and then he began to think seriously.

After a long time, the knifemaker said, "Maybe."

As Li Mengxi guessed, tempering requires heating the knife to a medium-low temperature that is half red but not red, and then placing it in a pile of burned charcoal to keep it warm for a period of time. This process is similar to "thawing", and the cold quenching process is

The formed iron crystals that are too hard melt away part of them.

The earth kiln has excellent thermal insulation effect, and the overall temperature in the earth kiln is at a medium to low temperature.

In addition, during the charcoal kiln firing process, charcoal will float all over the kiln, which is conducive to the carbon replenishment and carburizing treatment of the sword.

The forging process was finally completed. When I looked up at the sky, it was already afternoon.

The forging process of a palm-sized knife took half a day.

After the craftsmen helped polish and polish the knife, the blade was shiny and very beautiful.

I took it for a test and found that half of it could be penetrated by jabbing it into the wood. The sharp knife is indeed more penetrating than the tip of the Huanshou knife. Because of the thin blade, it is sharpened and can break the rope as soon as it is cut. It is very sharp.

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Back to the city lord's palace, Li Mengxi specially found a bone that was not easy to chew, and then used a knife to scrape the meat on the bone. The test result was very good. The knife was very sharp and could clean the tendons on the bone.

, and because the blade is sharp, it is easy to pick the meat in the seam. As a meat cutting knife, this knife is perfect.

The reason for making such a small prop has been around for a long time. It was when he was still fighting for the Yellow Turban. One day, Li Mengxi was stewing meat. He held the bones and gnawed and gnawed the meat on it. But if

If you throw away the bones, there will still be meat on them, which is a bit of a waste. It means eating without meat, and it is a pity to throw it away. The more you eat, the more angry you will become.

Thinking back to the logistics capabilities and marching conditions in ancient times, when the army divided the meat, they probably just roughly chopped the meat into pieces and then boiled it casually. There was no way to cook it carefully.

Therefore, when the army eats meat, it is mostly just bones with meat and muscles. However, the army is bitter and cold, and there are not many opportunities to eat meat. It is not easy to eat meat, but the bones are dry and cannot be gnawed clean, which is very uncomfortable.

Therefore, in addition to having a bowl, a sergeant should also be equipped with a small table knife. With this knife, it is very convenient to chew bones. It is also very convenient to pick wild fruits and peel cucumbers sometimes.

, with this kind of small knife, it is also convenient to treat the wound in case of being bitten by a snake. If there is no time to treat the injury caused by the sword, burning the knife red and cauterizing the wound can be an emergency. And if there is no knife, only an ordinary ring head can be used.

The knife has a blade as wide as a ring-shaped knife. When it is red-hot, a large piece of skin and flesh will be cooked.

This chapter is not over, please click on the next page to continue reading! I think a small knife does not use much iron, and all the soldiers can afford it.

But judging from today's forging experience, although the knife is small, the making process is indispensable and takes a lot of time.

It seems that unless the cost is reduced, it will be difficult for table knives to become popular among the military.

I found a piece of wrought iron bar that had only been quenched, and used a knife to cut the wrought iron. The cut moved, and although the blade was slightly blunt, it was generally intact.

Looking at the wrought iron again, there is an obvious scratch on it.

This shows that the strength of the blade is higher than that of wrought iron, which is about the same as steel.

Recalling that today's knife forging process was all done by Guan Yu. Guan Yu had no experience in forging swords, but he still successfully forged steel of barely acceptable quality. This shows that his guess about the principle of the entire knife forging process is basically correct.

Li Mengxi wiped the dagger clean and handed it to Guan Yu. He smiled and said, "General Guan, this sword was forged by your own hands for your convenience."

Guan Yu smiled happily and reached out to take the beautiful knife.

Li Mengxi said again, "If this knife is equipped with a small sheath or made foldable, it will be easier to carry."

The knife is positioned as an auxiliary tool, a table knife for scraping meat and peeling fruit. If it does not have a sheath, it will be extremely difficult to keep the knife well according to the soldiers' poor carrying conditions. Not only will it not bring much convenience, but it will also increase the cost.

A lot of trouble, which defeats the original purpose, so the knife must either have a sheath or be a folding knife.

Considering the technical difficulty, it is obviously much more difficult to fold the knife, so the scabbard is still simple.

After testing, the knife forging process is as expected. Decarburization, carburization, and heat treatment are generally understood.

Li Mengxi said to Guan Yu again, "I melted a basin of steel last night. If General Guan is free, he can order someone to remelt the steel and forge it into a sword."

Remember, filled steel is different from raw wrought iron. Filled steel is already steel, with no more carbon and no less carbon. Remember, it cannot be forged for a hundred times. If it is forged for too long and the carbon is removed too much, the steel will turn back into wrought iron.

Already."

"You can tell the craftsmen to omit the overlapping forging and directly hammer it into shape. Otherwise, we can still follow the old method."

Li Mengxi's words about Guangang were magical. The pot of steel had been boiled and left for a day. Guan Yu originally thought that Li Mengxi would be of great use to it, but he did not expect that Li Mengxi would give the steel to him. Guan Yu was stunned for a moment and nodded.
Chapter completed!