"I will report to Your Majesty that I will solve the problem of brittle pig iron. I think it must be annealed!" Zhang Yue bowed respectfully.

The annealing process has a long history of development in China.

According to later archaeological discoveries, annealing technology began to appear in the Shang Dynasty.

The annealing process of iron appeared in the early days of the Warring States Period when iron was first used.

In fact, the technology of softening and annealing treatment for the brittleness of white-mouth cast iron has been developed very well.

Shaofu has been trying to use brine and grease as annealing medium.

But the problem is that this annealing process depends on the personal experience and technology of the craftsman, and the processing is very difficult.

It is difficult to scale and can only be processed in a small amount.

Let alone deal with the pig iron that is as high as three million kilograms per year.

I'm afraid it's hard to complete 30,000 pounds!

As for the Han cavalry, roughly estimated, the calcinable cast iron required is more than 100,000 kilograms per year only if they are fully equipped with horseshoes!

Therefore, when the emperor heard this, he frowned and asked, "Is there no other way?"

"Then we can only use wrought iron..." Zhang Yue said with some disgust: "But werove iron is a dead end. If werove iron, I am afraid that our Han family's iron smelting technology will not be developed in the future!"

In the history of the development of iron smelting technology in humans, two scientific and technological trees have been taken by the East and the West.

In the East, China is mainly cast iron.

The continent of the West is mainly wrought iron.

Cast iron is to melt iron ore at high temperature, then process the obtained liquid metal into pig iron, and then cast it into iron castings.

Wrought iron is used to smel iron ore at relatively low temperatures. Because the smelting temperature is relatively low, the result is not a metal liquid, but a chemical reaction to reduce the iron oxide to metal iron. However, this metal iron contains more impurities, so it is necessary to forge while it is hot, squeeze out impurities to obtain forged and easy-to-process wrought iron parts.

China's cast iron technology tree is because of bronze technology that has been developed since the Xia, Shang and Zhou dynasties.

The ancient ancestors cast copper into tripods, pointing out the direction for future generations.

The craftsmen in the West and Europe will not deal with the liquid metal liquefied due to high temperatures.

Treat it as waste.

There is no doubt that the wrought iron tech tree is a dead end!

Although the wrought iron in continental Europe has the advantages of low carbon content and easy processing.

But the road ahead is gone!

In fact, the steelmaking technology and various converters of the steel industry in the later Western continents were redeveloped from the Chinese cast iron technology tree.

Even the forgings later called wrought iron were made by smelting iron ore at high temperatures and then refining pig iron.

Low temperature processing is a dead end!

There is no potential at all.

And the cast iron parts in the east seem too brittle, but in fact they are full of the future.

Even now, the craftsmen in Zhuxia can use their wisdom to process cast iron and use steel frying and steel filling techniques to process it into steel.

In fact, the various steelmaking furnaces in later steel mills were traced upwards. Their ancestors were the steel-frying techniques and crucibles used for steel-frying developed in the Han Dynasty.

So, if we now take the road of low-temperature wrought iron for convenience.

That is a disaster for the ages!

Moreover, it is actually useless!

Before the Industrial Revolution, ancient China's pig iron production was far ahead.

Even now, China's pig iron production is equivalent to the annual pig iron production in Britain on the eve of the Industrial Revolution.

There is certainly a reason for this.

The reason is that the production efficiency and production scale of cast iron, in any case, are far ahead of the wrought iron process.

Moreover, cast iron technology is difficult first and then easy.

White-mouth cast iron does have relatively few applications.

This is also because the initial iron was called "evil gold" during the Warring States Period.

However, since the development of the cast iron has far exceeded that of that time.

As for the output?

It's okay to raise the whole world.

In the long feudal history, the unique Eastern China was able to produce iron that was sufficient to meet the national military and economic use.

And the iron production of other countries and civilizations?

Even military needs are difficult to fully meet, let alone be used for civilian use.

Besides... the current production of pig iron in the Han Dynasty, including the worst-quality part, will only cost about three million kilograms.

It is approximately equivalent to 70,000 tons of pig iron.

If it is spread to every subject in the empire, it is less than fifty grams per person!

Then use the precious time and resources to play with wrought iron.

When will it take to reach the level of per capita consumption of one kilogram of pig iron per year?

The annual per capita pig iron consumption of one kilogram means that the Han Dynasty's pig iron production will reach about 500,000 tons.

When the pig iron scale reaches this level, it is possible to give birth to the first industrial revolution.

Steam engines, railways and machinery production have a material basis.

After all, China is too big and has too many people.

There are too many places that require steel.

Just a traditional small peasant economy can easily consume hundreds of thousands of tons of pig iron.

Pig iron can only have abundant output and enter industry after meeting the basic needs of agriculture.

After all, you can't let farmers go to work in factories on hunger.

It is impossible to let the army guard the frontier and defend the country on hunger.

The emperor, of course, does not understand the difference between wrought iron and cast iron.

But it doesn't matter. As a king, he doesn't need to know everything.

It's enough if someone understands it.

In view of Zhang Yue's performance so far, he believed it very much.

So, he convinced Zhang Yue's words and asked, "What do you mean?"

"I am stupid and think that I am the only way to adhere to the annealing path, develop better and more advanced smelting technology, and use the will of the country to continue to promote it!" Zhang Yue bowed and said: "Every year, the Shaofu must set aside a sum of funds for this matter, in order to carry out large-scale cast iron annealing operations in the future!"

Nowadays, heat treatment processes such as annealing and quenching are still in a rather primitive stage.

The process has not been spread through, but all it depends on the craftsmen's own experience.

How to anneale cast iron parts and what temperature is maintained?

It is judged entirely by personal intuition and experience.

Moreover, the smelting technology and iron smelting furnace technology are also very primitive.

There is still a long way to go to form scale and process, or even technical books to guide.

But the future is extremely bright!

Because, after the white-mouth cast iron is annealed and heat treatment, calcinable cast iron will be obtained.

The processing and mechanical properties of this calcinable cast iron will be instantly wrought iron process!

Even if it is just a very basic annealing treatment, the plasticity of the castings will be improved several times!

Even now, there are many craftsmen in the Han Dynasty who can complete this process through their own experience and skills.

If it can be popularized on a large scale, it will immediately improve the technical level of the entire country, drive the productivity of the whole society, and take a big step forward.
Chapter completed!