Hot.

There was a scorching heat in the air.

The orange-red color is the dominant color in this area.

"It's on!"

The blacksmiths shouted as usual, alerting others in the same area.

The hot liquid flowing from the blast furnace outlet is even more red.

Iron hooks are wrapped in thick fur.

Several blacksmiths worked at the same time to adjust the angle of the outlet, so that the hot liquid was poured into a funnel.

Slow.

Slow.

The blacksmiths endured the scorching heat.

They have long been accustomed to this temperature.

The funnel-connected mould is gradually filled with hydrothermal fluid.

In addition to the funnel used to hold the hydrothermal fluid, there are two small funnels on both sides of the mold.

The mould is boxy, lying on the ground, the blacksmiths scoop water from the funnel on both sides of the mould to pour, and the water pipes left in the mould continue to cool the mould from the inside out.

In addition to the heat transfer and cooling of the mold with water, the blacksmiths are also heating the mold.

In order to ensure that the carbon in the hydrothermal fluid is continuously precipitated.

Hollow casting method.

Zhang Qi adopted the cannon casting method after experimenting with a group of scholars for a long time in the world of riding and slashing.

During the period, I also experimented with the lost wax method and the clay iron mold method, and the advantages were different, and the disadvantages were also obvious.

The clay mold method depends too much on the mold material, once the clay used to cast the mold is not in place, the cast cannon body will be flawed and reduced to defective products.

Moreover, the clay mold method is a gun, and it has to be replaced with a new one, and the time cost is extremely high, Zhang Qi and they have tried to make clay molds, and often wait for its drying time to be one to two months.

The iron mold method is easy to use, the mold can be reused, and the gun mold made by the iron mold method can also reduce the workload of cleaning the surface of the gun body and cleaning the inner chamber.

At the beginning, Zhang Qi and most of them used the iron mold method to make the cannon body, but later it was found that the iron mold method also had great shortcomings.

Just a little heat dissipation is too fast, and it adds a lot of work to the casting cannon.

The lost wax method is to pour wax liquid on the basis of the mud mold, which has the advantage of high precision, but the disadvantage is the same as that of the mud mold, and even the temperature requirements for use.

That's right, the casting of cannons has begun, Zhang Qi took the time to go to the world of riding and cutting every day to study with a group of scholars, and it only took almost half a year to complete the casting and test firing of bronze cannons and iron cannons.

Now, the outside iron smelting factory has also begun to try to cast cannons through the technology brought out by Zhang Qi.

Different from the clay mold iron mold used in the early stage of the riding and cutting world, the hollow casting mold used by the outside iron smelting factory from the beginning.

This is the crystallization of the wisdom of a group of riding and cutting scholars, compared with the clay iron mold, the hollow casting technology almost absorbs the advantages of the two, and abandons most of the shortcomings.

Of course, the iron mold casting method was still taught to a group of blacksmiths, and the iron mold technology actually had a precedent in the Warring States Period, and most of the blacksmiths knew it, but at that time, the iron mold was just an iron mold, which was used to serve the auxiliary means of bronze casting.

Second, the iron mold casting cannon method is also easy to use for emergency production in wartime, which is faster and lower cost than hollow casting technology.

So after coming and going, Zhang Qi simply asked the blacksmiths to learn hollow casting technology and iron mold casting technology at the same time.

Little by little, time passed.

The mold of a hollow casting is cooled by water from the inside, and the carbon in the hydrothermal fluid is heated from the outside.

It wasn't until the craftsmen in charge of these two pieces of work were no longer in action that the hollow casting mold was dragged aside, waiting for it to be opened tomorrow.

There are eight or nine other pieces placed together with this mold, and now Liaodi is also considered to be a big business, and the mold manufacturing is of course one more made.

It's just that there are no results to show yet, and once it is confirmed that five of the ten molds can be used, then the hollow casting technology is considered successful and can be mass-produced.

A few days later in the afternoon.

Zhang Qi in the city lord's office received the news from the Shanhai Iron Smelting Factory, and was told that the mold could be opened, and the castings were almost cooled.

After receiving the notice, Zhang Qi naturally went immediately, and Hu Ling also followed, as the city lord of the frontline city, she also had a general understanding of the weapons that would be used on a large scale in the future.

By the time Zhang Qi and his colleagues arrived at the iron-smelting factory outside Shanhai City by horse, the blacksmiths had already lifted ten molds to the cement open space outside the field.

Since Zhang Qi, the blacksmiths who were busy beside the mold saluted him one after another.

"I'll see you!"

"Excuse me,"

Zhang Qi walked a few steps to the front, although the test firing of the cannon in the world went smoothly, but independent production in the outside world is the king, so he also attaches great importance to these molds.

"Let's open the mold."

"Okay!"

The blacksmiths had been preparing for a long time, and at this time, Zhang Qiyi said, and they opened the ten molds one by one.

The temperature is still a little bit, but it's not hot anymore.

The craftsmen took out the cannon body in the center, and the appearance was smooth and without grooves.

Zhang Qi looked at these metal cannons that shimmered in the sunlight and nodded involuntarily.

"Yes, look at the chamber and clean it up."

The cleaning of the cannon chamber was still a bit troublesome, and the personal guards took down the two horses from the horses, opened them, and put them behind Zhang Qi and Hu Ling.

The two were not polite, and went down and waited.

It took some time for the blacksmiths to clear the chambers of the ten cannons, and the central mold made of fine plaster made the chambers very smooth.

Although there are certainly subtle bulges, this can be solved by subsequent fine washing.

Moreover, this degree is enough for smoothbore guns.

Zhang Qi took a cannon from the hands of several craftsmen, although it was heavy, it was still within the controllable range of his strength.

This is just the cannon body, the iron casting itself is lighter than the copper casting, at first Zhang Qi also thought about direct steel casting, but thinking of the difficulty of refining after steel casting, he still chose iron casting.

Carefully placed one end on the ground, and Zhang Qi pointed the other end at himself to check.

Not bad.

The parameters are required to match under Zhang Qi's portable calipers.

These cannons, which were used to train the blacksmith's trade, were lightweight.

The thickness of the cannon wall is about three centimeters, and the boring hole is no more than ten centimeters in diameter and a caliber of one hundred millimeters.

Stretching out a finger, Zhang Qi groped in the boring hole for a while, but did not feel an obvious hand.

"Haha, yes, it's all hard work, and the craftsmanship can be called a master."

Zhang Qi stood up with a smile and praised the blacksmiths.

Then he turned his head sideways to Hu Ling and instructed.

"Bonuses will be given to all employees of Shanhaicheng Iron Smelting Plant, and those who did not participate will have two white dragons each, and each of these participating masters will be thirty."

"Okay."

Hu Ling nodded in response.

(End of chapter)