In terms of temperature, it is easier to make steel than to burn glass. Pen, fun, pavilion www. biquge。 infoSteelmaking is a link that every traverser can't bypass, so you might as well consider making steelmaking and making guns in a down-to-earth manner.

Later generations divided steel into three categories according to its carbon content:

The carbon content is less than 0.2%, and the melting point is 1538°C. Pure iron is very soft, and the nails of the stapler are pure iron, which can be broken with fingernails;

Steel with a carbon content of 0.2% to 2.1% is called steel, and the melting point of steel decreases as the carbon content increases. When the carbon content is 1%, the melting point drops to 1470 °C; With a carbon content of 2.1%, the melting point is 1380°C, so the furnace used to make steelmaking must be able to reach a minimum of 1380°C. In this range of carbon content, the steel will produce unique internal crystallization, so the steel has excellent properties, and it is best to make guns and guns to kill people and goods.

Cast iron with a carbon content higher than 2.1% is called cast iron and has a maximum melting point of 1375°C, while when the carbon content is 4.27% or higher, the melting point drops to 1148°C. The crystallization of cast iron and steel are completely different things. Cast iron is hard and brittle, making it unsuitable for weapons. There is often a story that when a family is about to be separated, the old man takes out the cast iron pot at home, and a stone goes down to break the cast iron into several pieces, and then the brothers are one by one, and after a few hundred years, the same family is divided into several branches of the pot edge, the pot state, and the bottom of the pot - you can see how brittle the cast iron is!

The temperature at which charcoal burns can only reach 1000°C to 1100°C when the oxygen supply is sufficient, and the maximum limit is 1200°C if you add a specially designed holding furnace. Therefore, no matter how much the charcoal stove is tossed, it can only be made of cast iron.

If you want to raise the temperature, you must use energy-dense fuels such as coal and gas.

Unfortunately, the sulfur content of China's coal is too high, whether it is directly smelted iron, or coke and then iron, it will lead to an increase in the sulfur content of the iron, resulting in hot brittleness - the iron that looks red and soft will be broken into slag like glass when hammered down, and it is simply scrap iron.

The desulfurization technology of coal is too complicated, so complicated that Sun Yi can't understand it at all. So Sun Yi could only turn to the next best, smelting cast iron first, and then finding a way to turn cast iron into steel.

Legend has it that there are three ways to turn cast iron into steel: frying steel, filling steel, and making steel.

Fried steel was sought after by many people in later generations, such as the introduction of fried steel in a certain article: "Fried steel is to heat pig iron to more than 1150~1200 °C, stirred in the molten pool, so that the carbon contained in it is oxidized, and the oxidation is completely become wrought iron or low carbon steel; When the decarburization is incomplete, the frying is terminated and the medium carbon steel or high carbon steel is obtained, and then the forging is made into a furnace. The invention of steel frying technology in the Han Dynasty in China was a revolution in the history of steelmaking, more than 1,800 years earlier than in Europe. ”

What a great invention!

As long as it is stirred in the molten pool above 1150~1200 °C, low carbon steel, medium carbon steel and high carbon steel can be obtained!

How can the experts called Baosteel and Anshan Iron and Steel be embarrassed! The things that the people of the Ming Dynasty could solve by digging a pond in the open air were so complicated by them!

How can all the people who made steel in 1958 be embarrassed! What the people of the Ming Dynasty could solve by digging a pond in the open air could not be imagined by hundreds of millions of people in New China!

-- The logic is very cruel, only one of the fried steel and Baosteel is right, and the other is deceitful.

Which steel is deceiving, you can figure it out with your toes!

Those who advocate the method of frying steel are ignorant, fearless and shameless!

1150~1200°C, you stir it again, it is also cast iron! - Ignorance.

Those who pursue the "steel frying method" are generally recognized as the most detailed introduction to the steel frying in the Ming Dynasty's "Tiangong Kaiwu", and there are illustrations as evidence.

In fact, there is no word "fried steel" in the original text of "Tiangong Kaiwu", and the text description and illustrations are all made of "wrought iron"!

Iron is raw and cooked, and it is a classification unique to the East. "Tiangong Kaiwu" records that "all iron is raw and cooked, and if it is not fried, it will be raw, and it will be cooked", and then the method of "frying wrought iron" was introduced in detail and flatly: the iron ingot obtained by direct solidification at the mouth of the furnace is pig iron, stirred with a willow stick, sprinkled with dry sludge powder at the same time, and then solidified iron ingot is wrought iron.

There is no disputing that the ancient "pig iron" was actually "white cast iron".

The ancient "wrought iron" was actually cast iron!

"White cast iron" is stirred with willow sticks in the molten pool, mixed with the carbon of willow sticks, and then sprinkled with mud powder, mixed with silicon in the mud, silicon helps carbon to exist in the form of graphite, and the "wrought iron" formed is actually "graphite cast iron" with increased toughness.

Because I don't know when it began, the definition of the word "wrought iron" in the dictionary has become "wrought iron is a ferroalloy carbon steel with a carbon content of less than 0.02%, also known as pure iron", so there is pig iron with a carbon content of more than 2% after "stirring" into pure iron with a carbon content of less than 0.2%, so of course the stirring half is the steel with a carbon content in between, this incredible logic. -- Fearlessly changed the concept of wrought iron.

So someone invented the "steel frying method", and then advocated it without question. -- Very, very shameless.

In fact, if you consult any ancient book, there is no word "fried steel". The word "fried steel" was also "invented" by later generations.

Filling steel, also known as group steel, is to mix the ancient "pig iron" and "wrought iron" together, and the ancients called it steel.

- Two kinds of cast iron, no matter how much you mix them, you can only get cast iron!

In the Northern Song Dynasty, Shen Kuo's "Mengxi Writings" clearly pointed out:

"The so-called iron and steel of the world's wrought iron, with soft iron bending plate, is trapped in the middle of the pig iron, mud sealing, forging into the same, called "group steel", also known as "filling steel". This is a pseudo-steel ear, temporarily fake pig iron is strong, and the second and third refining pig iron is self-ripe, and it is still soft iron. However, those who do not think it is wrong in the world do not know the true steel ears. ”

Translated into the vernacular, it is:

"The steel called wrought iron in the world is to bend the soft iron and roll it up, and then put the pig iron into it, and then wrap it in mud to smelt, and then add forging after smelting, so that the soft iron and the pig iron dope and penetrate each other, so that the steel that is exercised is called "group steel", also called "steel filling". This is actually a kind of fake steel, but temporarily borrow pig iron to increase the hardness, after two or three smelting, the pig iron naturally matures, and the result is still soft iron. However, no one in the world thinks there is anything wrong with this method, perhaps because they don't know what real steel is. ”

There is a key description in it: after two or three times of heating, the filled steel will lose its "steel" properties and return to soft iron. The proponents of "steel filling" never mention this passage.

Sun Yi is sure that using this kind of "steel-filled" gun to make a gun will definitely blow up the chamber!

Shen Kuo then went on to describe the real steel, the hundred steels.

"Yu sent an envoy to the Cizhou forging mill to observe iron smelting and know the real steel. Where there is steel in iron, if there is gluten in the face, and the soft face is exhausted, then the gluten is seen. The same is true for steelmaking, but take refined iron, forge more than 100 fires, each forging is called, one forging is light, to the accumulation of forging and two catties are not reduced, then pure steel is also, although a hundred refining is not consumed. This is the essence of iron, its color is clear, and when it is polished, it is dark and blue, and it is very different from ordinary iron. There are also those who have been refined to the end and have no steel at all, all of which are produced by the earth. ”

Translated into the vernacular, it is:

"I went to the forging mill in Cizhou to see ironmaking, and I knew what real steel was. If there is gluten in the dough made of iron and steel, just like wheat flour, gluten will be seen only when the soft noodles of the dough are washed. Steelmaking is also like this, only take refined iron, exercise more than 100 fires, weigh each forging, forge once light, until repeatedly forging and two catties are not reduced, that is pure steel, even if it is refined hundreds of times, there will be no more loss. This is the purest form of iron, and its color looks clear and shiny, but after polishing it it appears dark, green and black, which is very different from ordinary iron. There are also those where the iron is exhausted and there is no steel at all, which is related to the origin of iron. ”

The raw material of 100 steelmaking must be "fine iron", but unfortunately Shen Kuo did not explain what "fine iron" is.

There is a similar steelmaking method in the West called "block refining". At the furnace temperature of only 1000°C, the red-hot lumpy iron lumps are collected at the furnace mouth and beaten repeatedly until the impurities and carbon content in the iron lumps are knocked to the level of steel.

Logically deducing, Shen Kuo's "fine iron" is the iron lump in the Western "block refining method".

Why add a "fine"?

Because the content of ordinary iron ore in China is relatively high, the ordinary iron lumps collected directly at the furnace mouth will not withstand forging because of the hot brittleness. As the saying goes, "hate iron does not make steel".

Therefore, you must choose the best iron bumps.

In short, there is no shortcut to ironmaking, and honestly wielding a sledgehammer is the only way to go.

――――――――

References (not related to the plot, skip for uninterested readers)

The original text of "Heavenly Creation" about "frying steel" and "filling steel".

Where the iron is raw and cooked, it is raw if it is not fried when it is baked, and it is cooked if it is fried. Raw and cooked are harmonious, and steel is smelted. And every iron furnace is made of salt, and of clay. Its furnace is more than near the mountain cave, or with a giant wood Kuang enclosure, Shuo to make salt mud, the power of the poor moon is not allowed to make times. The salt mud is fine, and the whole work is discarded. Where an iron furnace carries more than 2,000 catties of soil, or uses hard firewood, or coal, or charcoal, the north and the south are convenient. The fan furnace bellows must be dragged by four or six people. After the soil is turned into iron, it flows out of the hole in the waist of the furnace. The furnace hole is first plugged with mud. At six o'clock in the day, one hour out of iron. The mud plug is forked when it is out, and the blast is remelted.

Those who make pig iron for smelting and casting will flow into long strips and round blocks, and use them within the range.

If wrought iron is made, the pig iron flows out within a few feet, and a pond is built a few inches lower, and a short wall is against it. Its iron flows into the pond, several people hold willow sticks to line up on the wall, first dry with the mud and mud, sieve the fine Luo such as noodles, one person quickly sprinkles the flowers, everyone willow sticks stir quickly, and immediately fry the mature iron. Every time the willow stick is fried, it is burned by two or three inches, and then it is even more. When it is slightly cold, there are those who cut it into squares in the pond, or those who propose to wave the spine to round the goods. If Jiyang Zhuye, I don't know this.

Where the iron and steel refining method, with wrought iron into a thin slice such as a finger wide, half an inch long, with iron pieces tightly bound, pig iron placed on it, (Guangnan pig iron name fallen son of raw steel is wonderful.) and covered it with broken grass and grass, (those who stick with the soil, so they do not speed up.) Mud-smeared underneath it. When the fire arrives, the raw steel is first melted, infiltrated into the wrought iron, and the two emotions are combined, and the hammer is taken out. Temper and hammer, and so on. The common name is group steel, also known as the steel filler.

Where the sword has a hundred refining and pure, placed under the eaves of the sun is full of brilliance, do not need to be raw and cooked and refined, also known as this steel for the next cloud. There are also those who quench swords with the ground, (the ground is naphtha and the like, not produced in China.) Yungang can cut jade, and the end is also seen. Where there is a hard place in the iron that cannot be beaten, it is called an iron core, and it is dispersed when it is coated with sesame oil. Where the yin of iron is produced, its yang is out of the stone, and there are several places that are not at all.