Please ask me to be the emperor

The "ten thousand kilograms of red barbarian cannon" mentioned by Governor Zhang is a typical siege gun, also commonly known as a siege cannon.

Zhang Shun and others followed Governor Zhang out of Ranxiang City and had just walked two or three miles. There was only a loud noise, like a thunderbolt on a sunny day, which frightened everyone and turned pale.

Before Zhang Shun could ask, Governor Zhang's expression changed and he blurted out, "Did it explode again?"

"What's going on?" Zhang Shun couldn't help asking.

"Just now, Dewen heard that King Shun had just cast two heavy cannons before he arrived in Langxiang. I specifically told them to wait until I came back to test the cannons. I thought they must have disobeyed my order. Unexpectedly, the test failed and the barrels exploded again! "Dudu Zhang responded with some shame.

After walking for a few more miles, everyone came to a mountain col, where they saw camps scattered around and a lot of people shouting. It turned out to be the place where Governor Zhang forged cannons.

Under the guidance of Governor Zhang, Zhang Shun and others soon arrived at the testing site and saw a group of people picking up debris on the ground.

Some were as big as a watermelon, some as big as a fist, and the largest piece was as big as a black pig.

Judging from the curvature of the shape, they are all fragments of the heavy Hongyi cannon, and the largest piece is the tail end of the cannon.

Zhang Shun walked over and bent down to pick up a piece from the ground. He bumped it in his hand and it was heavy.

He looked closely at the fragments and found that the workmanship was very rough.

Zhang Shun couldn't help but shook his head and said: "What exactly is the problem? Do you have any guesses?"

Governor Zhang also shook his head helplessly and sighed: "At first, I suspected that the molten iron was not good, so I added quicklime and refined it, but it's still the same."

"As a result, pig iron became wrought iron, so I had to take the opportunity to let the blacksmith forge the 'Flying Biao Gun' for use in siege."

As Captain Zhang spoke, he pointed to Zhang Shun at the four heavy mortars lined up not far away to show the results.

In addition to being consistent with the modulus transmitted from the West, the actual data of these so-called "flying guns" deviate greatly.

Since they are all forged from wrought iron, the actual weight is only about two thousand kilograms. They are used to fire "explosion bullets" and are very powerful.

In addition to being difficult to destroy the city wall, it is also very effective when used to deal with the garrison at the gate where the officers and soldiers fortify the city.

Governor Zhang continued: "When I found out that there was no big problem with the molten iron, I suspected that the craftsmen were not good at it."

"I sent people to Yangcheng again and hired a few old craftsmen with a lot of money to re-cast it, but it was still difficult to succeed."

"An old master gave me some advice. He thought that pig iron is hard and brittle, while wrought iron is soft and tough. If we combine the best of both worlds, we should have no worries."

"So, I ordered the craftsmen to forge the barrel and then wrap it with pig iron. However, judging from today's test firing, it still failed."

"Now that I am at the end of my rope, I would like to ask King Shun for some advice."

What? Composite metal cannons are out? Zhang Shun couldn't help but be surprised.

He remembered that he had heard of copper composite cannons in his previous life, but he did not expect that Governor Zhang could even think of pig iron and wrought iron composite cannons.

In fact, Zhang Shun was unaware of this. After artillery first spread to various places, due to the different levels of pig iron casting technology, many civilizations either directly cast cannons from copper or made cannons from forged iron.

However, when it comes to manufacturing heavy siege artillery, the cost of artillery made of copper or wrought iron may be unacceptably high, or the technical difficulty may increase sharply.

As a last resort, everyone unanimously chose composite metal as the artillery material of choice.

For example, in the Ming Dynasty, there were many flange machines made of copper and copper-iron composites. India also has similar siege cannons made of copper-iron and pig iron and wrought iron.

Although Zhang Shun was not unaware of the situation, it did not prevent him from understanding the huge advantages of pig iron and wrought iron composites.

When casting the "golden cannon" before, Zhang Shun carefully analyzed the stress on the barrel.

From a longitudinal perspective, the main stress point of the artillery is the medicine chamber.

The moment the gunpowder burns, it will explode with a huge impact, and then generate a large amount of gas to push the shell in the barrel to accelerate and do work.

Horizontally, the rapid combustion of gunpowder will have a huge impact on the artillery wall.

This kind of impact requires the gun body itself to have good tensile strength to resist it. This was also the main theoretical basis for the "equal strength substitution" in Zhang Shun's architectural design.

According to this theory, brittle and hard pig iron is not a material suitable for artillery at all; copper and wrought iron are slightly better, but not much better; only high-strength steel is an excellent material for making artillery.

But this is an era when "steel guns" and "steel arrows" are rare items. Where can there be so much steel for Zhang Shun to "waste"?

Even copper and wrought iron were still beyond his reach.

Thinking about the 10,000 kilograms of heavy artillery, which consumes 10,000 kilograms of copper or wrought iron at one time, Zhang Shun's flesh ached.

Especially for small cannons forged from wrought iron, it is okay. If heavy cannons are forged, the welding of the iron sheets will be a big problem.

A relatively elementary welding agent like yellow mud can still meet the needs when forging and welding smaller objects. If you want to forge weld large pieces of wrought iron, the technical difficulty is very high.

Therefore, it is a wise choice to properly forge the inner wall of the artillery and then strengthen the body with cheap pig iron.

Zhang nodded by the way and said: "I don't dare to give advice, let's discuss it together!"

"First of all, the composite method of pig iron and wrought iron is very good, and it must be the first choice for the heavy Hongyi cannon."

"Secondly, I see that this cast iron has many holes and gaps, like a honeycomb, so why shouldn't it explode?"

Governor Zhang reached out and took it, his face turned red, and he quickly defended: "King Shun didn't know something. It's not because the craftsmen didn't work hard, but the casting of large pieces is different from the casting of small pieces."

"When molten iron flows in, there will inevitably be some inconsiderations, which can lead to such a situation."

"As far as I know, even Western-made cannons and Guangzhou-made cannons can't avoid this!"

"What do you call this?" Zhang Shun said dissatisfied when he heard this, "If others can't do their best, can't we find ways to solve the problem?"

"I don't know much about cannon casting, but I have seen craftsmen casting gold and silver jewelry. They are exquisite and ingenious. How can this stupid thing compare?"

It turned out that Zhang Shun had several wives and two dolls at home, so it was inevitable that he would find a gold and silver craftsman to make some jewelry, longevity locks and other things.

Although the gold and silver jewelry of this era were a little rough, they were not as "bold" as this cast iron cannon.

Governor Zhang almost cried when he heard this. Aren't you being unreasonable?

He quickly explained: "Artisans making jewelry are completely different from casting cannons."

"Jewelry is delicate and is often cast with fine sand to achieve its precision. But artillery pieces are large, so it only takes time and time to make clay molds for casting..."

"Wait, wait!" Zhang Shun suddenly had an idea and asked quickly, "If that's the case, how can you cast a cannon without using fine sand?"