"Your Majesty, if you want to solve the problem of brittleness of pig iron, you think you have to anneal!" Zhang Yue bowed respectfully.

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

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

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

In fact, the technology of softening and annealing the brittleness of white cast iron has been well developed now.

Shaofu is already experimenting with brine and grease as annealing medium.

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

It is difficult to form a large scale, and only a small amount of processing can be carried out.

Not to mention dealing with the pig iron that is up to three million catties a year.

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

And the cavalry of the Han family, roughly estimated, is only a full replacement of horseshoes, and the calcinable iron required is more than 100,000 catties per year!

Therefore, when the Son of Heaven heard this, he also frowned and asked, "Is there no other way?" ”

"Then you can only use wrought iron......" Zhang Yue said with some disgust: "It's just that wrought iron is a dead end, if you use wrought iron, then I am afraid that in the future, my Han family's iron-smelting technology will not be able to develop!" ”

In the history of the development of human iron-smelting technology, the East and the West have walked two scientific and technological trees.

China in the East is dominated by cast iron.

The western continent of Europe is dominated by wrought iron.

Iron casting is the smelting of iron ore at high temperatures, and then the resulting liquid metal is processed into pig iron, and then cast into iron castings.

Wrought iron is smelting iron ore at a relatively low temperature, because the smelting temperature is relatively low, so what is obtained is not molten metal, but through chemical reaction, iron oxide is reduced to metallic iron. However, this metal iron contains more impurities, so it needs to be forged while hot, squeezing out impurities, and obtaining a malleable and easy-to-process wrought iron parts.

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

The ancestors of ancient times cast bronze as a tripod, pointing out the direction for future generations.

Craftsmen in Western Europe, on the other hand, do not handle molten metal that is liquefied by high temperatures.

Think of it as waste.

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

Although Eurofin's wrought iron has the advantages of low carbon content, it is easy to process.

But the road ahead is dead!

In fact, the steelmaking technology and various converters of the steel industry in Western Europe in later generations were redeveloped from China's cast iron technology tree.

Even forgings, which were later called wrought iron, were made by smelting iron ore at high temperatures to obtain pig iron and then refining it.

Low-temperature processing is a dead end!

There is no potential to speak of.

The iron castings of the Orient seem to be too brittle, but in fact, they are full of the future.

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

The various steel-making furnaces in the iron and steel mills of later generations can actually be traced upwards, and their ancestors are the crucibles used for frying steel and steel that were developed in the Han Dynasty.

Therefore, if you are now on the road of low-temperature wrought iron for convenience.

That's a legacy for the ages!

And, in fact, it's useless!

Before the Industrial Revolution, ancient China had been far ahead in pig iron production.

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

There's a reason for that, of course.

The reason is that the production efficiency and scale of cast iron, no matter in that case, are far ahead of the wrought iron process.

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

White cast iron does have a relatively small range of applications.

This is also the reason why the original iron was called 'evil gold' during the Warring States period.

However, today, the performance of cast iron has far exceeded that of its time.

As for the yield?

It's okay to hang the whole world.

In the long feudal history, only Oriental China was able to produce enough iron to meet the country's military and economic needs.

And the iron production of other countries and civilizations?

It is difficult to fully meet even military needs, let alone civilian applications.

Again...... At present, the pig iron output of the Han Dynasty, counting the worst quality, will only be about 3 million Han catties.

That's about 70,000 tons of pig iron.

Spread evenly to every subject of the empire, not even fifty grams per capita is enough!

Then use your precious time and resources to play wrought iron.

When and when will it be possible to reach the level of one kilogram of pig iron per capita per year?

The per capita annual consumption of pig iron is one kilogram, which means that the pig iron output of the Han family will reach about 500,000 tons.

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

The production of steam engines, railways and machinery had a material basis.

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

There are also too many places where steel is needed.

Hundreds of thousands of tonnes of pig iron can be easily consumed by a traditional smallholder economy alone.

And pig iron can only be produced in abundance after satisfying the basic needs of agriculture and entering industry.

After all, you can't make a farmer go hungry to work in a factory.

It is also impossible to let the army go hungry to guard the frontier and defend the country.

The Son of Heaven, 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.

Someone can understand it.

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

Therefore, he also believed Zhang Yue's statement and asked, "What does that Qing mean?" ”

"The minister is stupid, thinking that he is the only one to insist on the road of annealing, develop better and more advanced smelting technology, and use the will of the society to persistently promote it!" Zhang Yue bowed and said: "Every year, Shaofu must set aside a sum of money for this matter, in order to carry out large-scale cast iron annealing operations in the future!" ”

At present, heat treatment processes such as annealing and quenching are still in a fairly primitive stage.

There is no process to circulate, relying on the experience of the craftsmen themselves.

How to anneal iron castings and at what temperature?

It's all based on personal intuition and experience.

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

There is still a long way to go to form a large-scale and process-oriented process, and even, to appear technical books to guide it.

However, the future is extremely bright!

Because, after the white cast iron is annealed and heated, it will obtain calcinable cast iron.

The machining and mechanical properties of this calcinable iron will be a wrought iron process in an instant!

Even if it is only a very rudimentary annealing treatment, the plasticity of the casting will be increased several times!

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

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

Not to mention, the popularity of Quyuan plough alone will also increase exponentially!