It is no longer possible to make a hundred steels into finger twists, but the method proposed by the Son of Heaven to melt iron into steel ingots has been realized through the crucible steelmaking method.

If today's son said that the iron is directly smelted into molten iron, it is even simpler than making porcelain.

Melting iron into molten iron, Bi Maokang and Song Yingxing have also done it before, and now the cast iron cannon for the new army is produced in this way, but when it comes to directly melting molten steel, the two of them are still skeptical.

Doesn't steel need to be forged?

But now seeing the liquid molten steel flowing out of the outlet of the furnace, Bi Maokang was excited to pay a tax.

But within two days of the two being happy, there was a problem with the formed steel.

The swords and other weapons formed in the mold are more brittle than pig iron in the experiments after forging, and they are even more incomparable with the previous crucible steel.

After reporting the situation to the Son of Heaven, Zhu Youzhen couldn't bear it anymore and rushed to Xishan in a hurry.

In fact, Zhu Youzhen is still very happy about the liquid molten steel flowing out, and he can smelt the iron into liquid, which shows that the smelting level of Xishan Iron and Steel Plant has stepped into the road of industrialization.

As for the lack of toughness of steel, Zhu Youzhen knew that it was caused by the inappropriate ratio of iron and carbon.

In order to refine crucible steel, Xishan has a large number of graphite minerals before, and as long as continuous experiments, the appropriate proportion can definitely be found.

When Zhu Youjian arrived at Xishan, he first affirmed the work of Bi Maokang, Song Yingxing and the general workers of the steel plant, and then pointed out the reason why the steel was too brittle.

This made Bi Maokang and Song Yingxing instantly relieved, both of them thought that it was a problem with the process, thinking that it needed to be overhauled, but at this time, it was determined that it was a problem of proportioning, and it would be much easier to solve, as long as they kept experimenting.

Moreover, according to the instructions of the Son of Heaven, according to different needs, steel with different toughness can also be made, and Zhu Youzhen also instructed Bi Maokang and Song Yingxing to label the steel according to the ratio to distinguish different uses.

By the end of May, Daming and even the world's first qualified open-hearth molten steel finally flowed out.

Because the iron mold used to cast the cannon in advance had already been formed, ten days later, the first steel cannon in the history of the Ming Dynasty was formed by direct pouring of molten steel.

Regarding the iron mold casting cannon, as early as when the first cannon was cast in Xishan, Zhu Youzhen felt a little inappropriate when he saw the craftsmen at that time casting the cannon with clay, and later learned that because of the need for drying, it would take several months to make a cannon, Zhu Youzhen was completely speechless, and even proposed the iron mold casting cannon method.

Zhu Youzhen proposed that the iron mold casting cannon method was not based on the insight of later generations, but felt that the clay mold casting cannon needed to be dried and wasted time, so why not use iron molds, and there were all kinds of molds in later generations.

Since the clay mold is too slow, why not change it, based on this, Zhu Youzhen casually proposed the iron mold, but he didn't expect to casually achieve a new casting method.

Of course, this has also been through the continuous pondering of Bi Maokang and Song Yingxing, and the experiments of craftsmen again and again.

After more than a year of development, Xishan has summed up a set of mature iron mold casting methods, and successfully compressed the casting time from half a year to one month.

With the continuous improvement of the casting technology and the proficiency of the craftsmen, the assembly line production method invented by Zhu Youzhen is mainly adopted, and the current casting time has been shortened to half a month.

Moreover, in addition to the three-pounder cannon at the beginning, the iron mold of the cast cannon later developed to the six-pounder and nine-pounder guns.

Of course, before the success of the open-hearth steelmaking method, most of the cast guns were three-pounder and six-pounder guns, and no matter how large the nine-pounder guns were, they no longer met the requirements of Zhu Youzhen's field guns.

A nine-pounder cannon weighs more than 6,000 catties, plus the wheels are more than 8,000 catties, and six horses need to be dragged on the flat ground, and the speed is even faster.

However, the nine-pounder cannon can launch an eight-pound iron ball two miles away, and in the case of increasing the charge, the ultimate firing range can reach three miles, and the power is indeed not small, and it is still possible to defend the city, and the field battle is a drag.

Moreover, a cannon requires six horses, ten baggage soldiers, and six professional gunners to serve, which is really a bit large.

The artillery that Zhu Youzhen wanted was actually a light artillery, and its weight should not exceed 1,000 catties, so that two horses could pull and run, and four soldiers could push it if necessary, so that the mobility could meet the standards of field warfare.

The firing range should be up to two miles away, and the rate of fire should be maintained at a rate of one shot per minute, so that the powerful artillery can be applied to the battlefield.

Of course, Zhu Youzhen remembers that the Napoleonic guns of the late 18th and early 19th centuries met his requirements.

Zhu Youzhen remembered that in his previous life, he had watched a documentary on the Civil War, and the twelve-pound bronze cannon was only more than 3,000 catties, and a skilled gunner could do two or even three rounds a minute.

But because Daming really lacks copper, a precious metal, he can only look at copper and sigh.

The cast-iron cannon of the same power is too bulky and has basically no field value.

But now, with the success of the open-hearth steelmaking method, Zhu Youzhen can finally use steel to cast cannons.

Because the steel structure is tougher, the barrel does not need to be as heavy as a cast iron cannon, and the weight is naturally reduced.

The weight of the three-pound cannon made of steel was only more than 500 catties, and the total weight of the steel wheels did not exceed 700 catties, and two strong men could push it on flat ground.

The total weight of the six-pounder cannon is also controlled at 1,000 catties, two horses can be pulled and run, and four strong men can also be pushed.

These two types of artillery basically met Zhu Youzhen's requirements for field guns.

Because of the reduction of the weight of the gun body, Zhu Youzhen felt that the steel-cast nine-pound cannon and the twelve-pound run might not be impossible to use in field battles.

The caliber of the artillery is naturally as large as possible, and the firing range of the artillery is naturally as far as possible, so with the success of the experiment of the three-pounder gun and the six-pounder gun, the Xishan Ordnance Factory is developing a larger caliber artillery.

Because of Zhu Youjian's historical golden finger, after entering June, the Xishan Ordnance Factory and the Iron and Steel Factory began to cast cannons day and night.

Zhu Youzhen did not hesitate to spend money on this, and smashed the silver into it, and all the steel produced by the Xishan Iron and Steel Plant was also used to cast cannons.

While studying the open-hearth steelmaking method and cannon casting, Zhu Youzhen began the process of recruiting troops and horses to deal with the very likely outbreak of the change in his own country.

At present, there are a total of 9,000 new troops in Xishan, of which more than 2,000 belong to the baggage, engineering, medical, and cooking branches, and the actual number of soldiers is less than 7,000.

Among the less than 7,000 soldiers, there are still 1,000 people in the mountains of Guizhou who are following Zheng Ruxin to reform the land and return to the stream.