The scientific and technological content of casting barrels is much lower than that of steelmaking. Pen, fun, and www.biquge.info

However, due to the technical difficulty of the process, casting is more difficult than smelting.

The difficulty lies mainly in thermal expansion and cold contraction.

Casting a hollow large iron bucket is actually very simple. However, in order to ensure that the cannon does not explode indiscriminately when it is fired, the thicker the wall of the barrel, the better.

Once the wall of the cannon barrel is thickened, the problem of thermal expansion and cold contraction will be very painful.

After the hot molten iron or molten steel is poured into the mold, the order of natural cooling is naturally that the outer ring surface layer is fluted first, and the inner diameter is cooled last.

This becomes a nightmare problem that the cannon forger can't overcome.

The red outer ring steel pipe is cooled first. Cooling must shrink. The contraction will squeeze inward. At that time, the steel structure of the inner ring was still red, hot, and soft...... This extrusion, the inner diameter of the metal lattice structure, will be squeezed miserably.

The rigidity, toughness, and ductility of metals all come from the unique lattice stress structure of metals.

The gods of the Commission have repeatedly emphasized stress as the key.

Wu Song didn't know what stress was. But it has been popularized by the gods in an easy-to-understand popular version. For example, the refined steel is soft around the fingers, such as the Damascus iron steel knife, which is both sharp, tough, and rigid. But the great god of the committee asserted that if the Damascus saber was heated, it would be beaten indiscriminately with a hammer. The knife will become brittle and easy to break.

The principle behind this is that the high temperature beating, if the rhythm and angle are not scientific, will destroy the stress structure of the metal lattice. It loses its original rigidity, toughness and ductility.

A more straightforward example is that a steel bar with full elasticity (although there is no large-scale steelmaking, the small forged steel pieces forged by blacksmiths have long been available) will bend when broken hard. Once you let go, it will bounce back to its original shape.

However, after dozens of continuous operations of such a bending action, the bending point will heat up and become soft due to the accumulated stress energy, and then it can no longer recover its original elasticity.

Or, if this good steel is full of elasticity, it will be bent for several hours in a row, which will also lead to the loss of elasticity and never return to its original shape.

What does this mean? The extremely excellent rigidity, toughness, and ductility of rigid materials do not exist constantly. It has a stress limit threshold on an internal lattice structure.

Beyond the threshold, it exhibits excellent stiffness, toughness, and ductility.

Once this critical value is exceeded, the steel part is also wasted.

In later factories, whether it is rebar, steel bar, or military steel core warhead, it is strictly forbidden to beat. If the steel rod is slightly bent, it needs to be straightened with extreme care by professional equipment.

A bent steel rod can actually be straightened with a few hits with an iron hammer. But the engineer forbade the migrant workers to do such nonsense. Because this brutal beating and straightening method will destroy the stressed structure.

Therefore, in the process of casting the cannon, the outer diameter is cooled first, which will destroy the stress lattice structure of the inner diameter.

As a result, the barrel was made very thick, and it was still necessary to burst the chamber. Further increase the diameter of the mold, pour more molten iron, and the structure leads to a higher burst rate. For ancient craftsmen who did not know what the internal stresses of the metal lattice were, this seemed like a big curse.

There is a will from the gods in the dark, and the caliber of human cannons cannot be increased. When it is increased to a certain level, the strength of the barrel of the cannon will become more and more slag.

In fact, it is the thermal expansion and contraction that leads to uneven cooling, which in turn leads to the destruction of the metal lattice structure.

None of the travelers on the committee had any practical experience in making steel and casting cannons using the local method......

But two of them have seen Lingao Qiming.

Although Lingao Qiming is also terrible in many ways (such as the setting of the navigation clock and the shrapnel, which completely deviates from the rigorous scientific style of the book, and is suspected to be a fake Lingao Qiming), I still have to thank the braggart for providing important science in terms of barrel cooling.

According to the book, the Americans first had a brainstorm, thinking of using cold water to flow through the center of the mold, and giving priority to water-cooled cooling of the inner diameter of the gun barrel. This is completely devoid of technical content, and a major scientific and technological problem has been solved just by relying on brain holes.

With this secret, the traverser can undoubtedly crush all non-traversal opponents in the field of cannon manufacturing.

After all, according to serious history, Americans did not open this brain hole until 18XX. Therefore, Liangshan crosses technology and can fight the invincible opponents in the world for hundreds of years to come. (At this moment, the Liangshan committee members did not know that the class enemy who was disorderly and foul had secretly brought over the 1853 Enfield product, which was much better than the Napoleonic cannon.) ）

It's easy to say, but hard to do.

The mold for casting the barrel of the cannon has to be filled with cold water in the middle, and it has to be flowing. This process is not easy! Fortunately, my big flower grower has never lacked skilled carpenters. In this work, the scientific bottleneck has been solved, and the rest is nothing more than craftsmanship. Recruit a large number of craftsmen, this is the true backbone of building an invincible artillery empire. If the recruitment is not effective, in fact, kidnapping or arresting is not impossible to consider.

So the committee first went all out to find the jade arm craftsman Jin Dajian.

The task was completed very smoothly.

That Jin Dajian was very clumsy, drank a few good drinks, paid a few salaries, and visited a few green buildings at public expense, and immediately joined the Liangshan gang.

However...... This guy disappointed the committee, he is a master of carving fake official seals with turnips. It's not a Luban talent at all.

There's no way, carefully go through the Liangshan 108 list, there is really no half Luban here.

So the committee immediately quarreled.

Half of the left-wing members advocated resolutely and mercilessly falsifying history, looking for Luban, and buying up a large number of Han Luban. If there were also barbarian Lubans in Khitan, Qiangzang, Jurchen, Kimchi, Zhenla, and Annam, they would all be arrested and joined.

The other resolutely upholds the inherent order of historical time and space, and does not allow anyone to disturb it.

Wu Song is not a traverser, and it is inconvenient for him to get involved in this kind of linealist controversy.

He focused on his own business.

Go to the Fan Lou Club in Tokyo City to hook up with Master Li, say some good things to Zhao Ji, and delay the Liangshan uprising as much as possible.

Wu Song had quite a lot of room for free manoeuvre, and when he found out that Li Qingzhao might be better than Master Li, he had the right to shift the focus of his work to Liang Hongyu.

Finally, take into account the search for a few master craftsmen who can make clocks.

History can be disturbed, or it cannot be disturbed, and the members of the Liangshan Committee quarreled fiercely, but on the matter of making the clock, both sides unanimously said: This seems to be possible.

So Wu Song was also impatient to stay in Shuibo every day to watch those committees tear up and fight, so he simply went on a business trip, and by the way, he was looking for some masters who made clocks.

Now he felt that this Xianyuan County, that is, Qufu, was worthy of serious investigation.

If Xianyuan County does not find clues, Jinan Mansion, that is, Li Qingzhao's hometown, seems to have some need to investigate.

Jinan, Jinan and the south of the Qingji River, is also the place where the dragon veins once entrenched by the Eastern Emperor passed, and the descendants of the Eastern Emperor are undoubtedly good at making clocks.

Well? Shouldn't Jinan be on the south bank of the Yellow River?

It just so happened that Liang Hongyu was a human cushion for Zhao Yanqing, and he couldn't sleep all night, Wu Song was awakened by Heming, and said good morning to Hongyu Little Lori.

Then he inquired casually: "This Jinan Mansion is obviously on the bank of the Yellow River, why don't you call Huang Nan Jinan?" ”

……