Inside the 101 laboratory.

"Barrel?" Wang Yingxuan pushed his glasses in surprise.

"Barrel?!" Zhao Shizhen also exclaimed, but it was more of a surprise.

If you want to ask what he is interested in in this world besides guns, it must be guns.

"The cylinder and barrel structure are similar, and the requirements are similar." Zhang Jian was not surprised, he had obviously adapted to the rhythm of Zhao Hao's antelope hanging horns. "If you can cast a qualified cylinder, the barrel will definitely be no problem."

"Well, that's against the law......" his brother-in-law said timidly.

It's okay to build a gun in the name of the county. If you build a cannon, my God, I can't believe it......

"I forgot to introduce to you, the full name of the 00 Institute is the Ordnance Research Institute of the Ordnance Bureau of the Ministry of Industry in Nanjing." Zhao Hao smiled and gave the honest four-eyed old Qin a reassurance.

"Oh, that's it......" Wang Yingxuan suddenly said, "No wonder 00 is not with us."

"The last time I saw it at the Ordnance Bureau, most of the imperial court was copper cannons," Zhao Shizhen recalled: "The Hongyi cannon is made of cast iron, but the barrel is as thick as the beam, and the barrel is a little larger than the fist." ”

He is the director of the Ordnance Research Institute, and he is so good that he naturally said: "The best artillery factory in the Ming Dynasty now is the Bugarao Cannon Yard opened by the Franc Robot in Haojing Ao, and I heard that the copper cannons they supply to their own people are all copper cannons. ”

"Hmm." Zhao Hao nodded. He also thought about poaching the Franc machine craftsmen from Bugarao, but if it is not my race, his heart will be different. Narrow-minded nationalism, Zhao Gongzi did not start poaching.

After the failure of pig iron casting, there were three ways in front of him, one was to innovate the casting technology.

The reason why the cast iron cannon barrel is still embarrassing and useful when all the details have been paid attention to, in the final analysis, is the defect caused by natural cooling.

Because in the case of static natural cooling, the outer wall of the gun is cooled first, and then cooled down from the outside in. This causes a serious problem - after the outer layer is cooled and hardened, the inner layer has not cooled, and as a result, the outer layer is harder than the inner layer, and the inner tube of the inner layer will be pulled and deformed, and even directly cracked.

This naturally leads to a high scrap rate when casting cannons, and it will also explode directly, making gunners daunting.

Therefore, at this time, whether it was the Ming Dynasty or the Taixi people, they could only thicken and thicken the iron cannon barrel, but the cannon cast in this way was bulky and powerful, and it was naturally difficult to please the military.

It was not until the Civil War in the United States that an engineer named Rodman invented the 'inner mold water injection cooling method', which allowed the barrel to be cooled first inside and then outside, which solved this problem.

This method is simple to say, it is only necessary to replace the inner mold of the barrel with a hollow one in the cooling process, and then cool it with circulating water.

But this is only a theory that Zhao Hao sees from books, and it is still far from being implemented - for example, what is the relationship between water velocity and temperature change?

In the middle of the 19th century, when thermodynamics was well developed and there were relatively advanced measurement and control conditions, it took Rodman a full decade to establish a relatively scientific and complete data system.

There is no other way, only to keep repeating trial and error, and see which day the blind cat can meet the dead mouse.

The expectation in Zhao Hao's heart is to overcome this casting method within five years. After all, he has an advantage that Rodman doesn't have, as long as he does a lot of experiments, he can pile up the money.

But the innovation of casting technology is actually only a symptom, the real king is to innovate smelting technology!

In another time and space, when the pig iron refining reverberatory furnace appeared in the late eighteenth century, the British could re-smelt the molten pig iron to remove impurities and make the molten iron purer. The British Navy did not have a single bore-chambered cannon cast from this wrought iron. Finally, the bronze cannon was completely eliminated.

However, at present, the metallurgical technology and steel output of the Taixi countries are still far behind the Ming Dynasty. The technology that the Ming Dynasty didn't master, and they naturally didn't understand it.

Zhao Gongzi only knows a concept about this, and how to do it is even more blind.

In fact, the Wuhu blacksmiths who produced 'Suzhou Steel' in the Ming Dynasty have long been able to skillfully use the steel filling method to control the carbon content in wrought iron. And according to the demand to produce a variety of carbon content of steel. It wasn't until 200 years later that the Europeans invented the crucible steelmaking method.

But whether it is the steel filling method or the crucible method, there is a serious problem, that is, the production volume is too small and the cost is too high.

That's why there is a saying that 'good steel is used on the blade'.

In short, people in this era can't imagine who would use precious steel to cast cannons?

However, in the next few hundred years, all the world's powerful countries will be made of steel, so no matter what the cost, Zhao Hao will have to deal with the mass production of this damn steel.

When the first two methods are far from quenching the thirst, only the third method, 'casting a cannon with copper', is the only solution that can work immediately.

In fact, for a long time after the birth of the cannon, most of the time it was the bronze cannon that played the leading role. All countries have a long history of copper cannon casting, and the Ming Dynasty naturally also has mature casting technology.

Copper is corrosion-resistant, not easy to rust, good ductility, not easy to blow up, low melting point and easy to cast. Therefore, the copper cannon was also more powerful than the iron cannon for a long time.

The only problem is that it's expensive. Especially in the Ming Dynasty, copper is money!

Taking the current bronze cannon of the Franc machine man as an example, the ship's heavy gun is about one ton, and the light snake cannon is also 400 catties.

The Longqing Tongbao of the Ming Dynasty weighs one penny and three cents, and contains ninety-fifty percent copper.

A heavy artillery cost 216,000 yuan for materials alone, and the cost of not less than 250,000 taels of silver, including labor and wear and tear.

The cost of the snake cannon is more than fifty taels.

And the capital ships of the Spanish or Franc aircraft were to be equipped with twenty to forty heavy guns alone. The number of light guns of all kinds is even more incalculating.

Not counting the cost of the ship, just to put the cannon in order, it will cost 10,000 taels......

~~

Zhao Gongzi silently thought about it, and suddenly felt that he was afraid that he was not so rich.

The Spanish Empire could be impoverished by an arms race, let alone a child's family.

Thinking of this, Zhao Gongzi stared at the four-eyed brother with a hideous face and said, "Even if you cast the bronze cannon first, you must not relax on your side." Within five years, I was able to overcome all the problems of converter steelmaking...... And five sons! ”

"Uh......" Wang Yingxuan took off his glasses and wiped them up. Similar to the 'water-cooled casting method', the principle of converter steelmaking is also very simple. But this is more of a system engineering, without a long period of testing and improvement, there is no application at all.

But fortunately, five years should be enough.

But how can you do such a thing as giving birth to five sons in five years?

Unless...... But the brother-in-law is the top boss, and he doesn't dare to think about it at all.

ps. The first update of the three consecutive changes.