Soon after the invention of ironmaking, humans learned to make steel. Because steel has better physical, chemical and mechanical properties than the original pig iron, it was quickly used in large quantities. However, due to the limitation of technical conditions, people's application of steel has been limited by the output of steel.

The steel smelted in the early human era was generally made by carburizing after low-temperature reduction smelting, and the whole process was about two steps: the first step was to smelt the iron from the ore, and the second step was to carburize the iron from the block iron.

During this carburizing process, it is constantly folded and forged to aid in the diffusion of carbon. The steel obtained in this way is called block iron carburizing steel. Weapons such as the Yanxia Dugang sword are made of this steel.

If it is properly controlled, there are also those that are reduced and smelted into steel at one time without going through the second step, and this kind of steel is called block steelmaking or natural steel.

The strength and hardness of these two kinds of steel are higher than that of block ironmaking, but there are also obvious shortcomings, the carbon content of the steel obtained is generally low, the carbon distribution is often not uniform enough, and the steel contains more inclusions, of course, the biggest disadvantage is that the productivity is low.

In the Central Plains cultural area, this steel-making process was used until the middle of the Western Han Dynasty, and then it was gradually replaced by the invention and development of fried steel.

The steel structure obtained by the frying method is also more uniform and dense.

With the invention and popularization of the steel frying method, the use of steel has become more common. As a result, iron weapons such as knives and swords eventually completely replaced copper weapons, but they were still rarely used in agriculture and handicrafts.

The steel-filling method is a much more advanced steelmaking technology than the steel-frying method. It is to take advantage of the characteristics of high carbon of pig iron and low carbon of wrought iron, and pour molten pig iron liquid onto wrought iron to change the carbon content to produce steel with high hardness and good performance.

At high temperatures, the carbon and silicon, manganese and other oxides in the liquid pig iron are mixed with the oxides in the wrought iron to undergo a violent oxidation reaction, which can remove impurities, purify the metal structure and improve the quality of the metal. Therefore, the steel filling method can reduce the number of repeated folding and forging and improve labor productivity; Moreover, the steel filling method is easy to operate, easy to master, and easy to promote.

Originally, at the end of the Eastern Han Dynasty, there was already a prototype of the steel filling method, but this technology was very immature, and there were very few people who mastered it. The steel filling method that Li Pengfei obtained from the system is a very perfect technology summed up by later generations. It can be said that compared with the prototype of the steel filling method that appears today, it is at least 1,000 years advanced.

With this method, Li Pengfei was able to produce a large number of steel weapons. This has a tremendous effect on both combat and production development.

It can be imagined that on the battlefield, Li Pengfei's army fought with other people's armies, and all the weapons of other armies were cut off by the soldiers of Li Jiajun.

Of course, this can only be a beautiful imagination in a short period of time.

A technology, even if it is a mature technology, if there are not enough talents, it is difficult to be popularized in a short period of time. And talent is Li Pengfei's biggest shortcoming today.

Although he has collected a lot of talents in this area in the past two years in the Northland, and has also opened a blacksmith shop exclusive to the Li family, there are only a dozen blacksmiths with skills and knowledge in it.

Even if these dozen blacksmiths can all master this technology, it is tantamount to a drop in the bucket for an army of tens of thousands and hundreds of thousands. Not to mention the use of steel in production and life.

But it is better to have technology than no technology, and talents can be cultivated if they do not have them. However, if this technology is not available, it cannot be available in a few years or ten years.

Li Pengfei immediately found Li Zheng, the person in charge of the Li family's blacksmith shop, this is an old man of the Li family whose loyalty has been confirmed by Li Pengfei, and he followed Li Jin to northern Xinjiang at the beginning. Li Pengfei handed him the technical information of the steel filling method, and after the old man read it, he almost fainted with excitement, and this kind of technology was simply unimaginable to him.

It took a lot of effort for Li Pengfei to calm down Old Man Li. Later, he carefully told him to thoroughly understand this technology and teach it to a credible blacksmith, so as to achieve mass production as soon as possible.

For such a request, Old Man Li naturally has no doubt. As an old man who has been in the blacksmith industry for decades, he knows very well the significance of this technology. Now Master Li has a lot of ambitions, and this technology has helped his career a lot. But if it leaks, it can also cause great harm to it.

……

After handling the matter of the steel filling method, Li Pengfei began to be busy with other things. In another month, the Yellow Turban Rebellion will break out, and he still needs to do too much preparation.

Just after the New Year, Zhao Yun and Zhang Fei came together as promised.

And the world is also developing and moving forward according to its fixed trajectory.

At the end of January of the seventh year of Guanghe, Ma Yuanyi, a generous man of Taiping Dao, was betrayed and arrested by his subordinate Tang Zhou in Luoyang, the capital, Ma Yuanyi was torn apart, and the officers and soldiers vigorously arrested and killed believers in Taiping Dao, more than 1,000 people, and ordered Jizhou to hunt down Zhang Jiao.

Due to the suddenness of the incident, Zhang Jiao was forced to move forward the incident by one month and attack in February.

The Yellow Turban Uprising broke out on time according to Li Pengfei's memory.

Because the insurgents tied yellow scarves on their heads, they were called "yellow scarves" or "moth thieves", and they started in the northern Jizhou area. Zhang Jiao called himself "General Tiangong", Zhang Bao and Zhang Liang were respectively "General Digong" and "General Rengong", they burned down the official mansion, killed officials, looted everywhere, within a month, there were wars in 28 counties in seven prefectures across the country, the Yellow Turban Army was like a bamboo, the prefectures and counties were lost, the officials fled, and Kyoto was shaken.

Guan Yu and the others saw that what happened really as Li Pengfei expected, and they were even more convinced of him. Originally, the three of them were enthusiastic at that time, and they demanded to send troops to suppress the thieves immediately. However, Li Pengfei thought that the time had not yet come and rejected the proposal of the three.

Of course, Li Pengfei did not refuse arbitrarily, but told the three of them the reason.

After listening to Li Pengfei's explanation, the three of them also felt that Li Pengfeilong was right.

Li Pengfei's explanation is very simple, that is, the Li family is still under the ban of the party, and there is no edict from the imperial court, so they are not justified in sending troops.

As for Yue Fei, this guy carried out all Li Pengfei's orders without any doubt.

Of course, although Li Pengfei did not send troops immediately, he did not sit there and wait, but was accumulating strength for the upcoming troop dispatch.

Originally, Li Pengfei trained 500 Zhuang Ding in Lijiazhuang, these are all good men from the north who are equipped with horses and superb riding skills, and as long as they are slightly adapted, they are elite cavalry.

Li Pengfei's first step was to reorganize these 500 Zhuang Ding into Wutun cavalry, and after 10 days of special training, these Wutun cavalry was rapidly expanded.

After the outbreak of the Yellow Turban Rebellion, Li Pengfei had already let his Li Family Chamber of Commerce start recruiting soldiers in the Northland, of course, this recruitment operation was carried out in secret.

Despite this, because of the disasters of the past two years, there are too many ordinary civilians who can't survive in the two states. Especially now that the Yellow Turban Rebellion has broken out, the two prefectures can be said to be starving all over the country, and as long as they are given a mouthful of food, they can recruit countless people, not to mention the superior conditions provided by Li Pengfei.

Within half a month after the outbreak of the Yellow Turban Rebellion, the Li Family Chamber of Commerce took in more than 20,000 refugees, selected 5,000 able-bodied people from them, and sent them to a military camp secretly established by Li Pengfei on the shore of the Bohai Sea.

So far, the number of soldiers under Li Pengfei has reached 5,500.

It's just that it's really hard to say that these armies have combat effectiveness, because there are a full 5,000 recruits who have not undergone much training.

Fortunately, it is only mid-February, and there are still nearly two months before Li Pengfei plans to send troops, so he can seize the time to train these soldiers.

The Li family's operation to take in the refugees is still going on, but Li Pengfei has no plans to continue to expand the size of the army in the short term.

With his current strength, feeding these 5,500 cavalry has reached the limit, and he is no longer able to expand.

As for the infantry, Li Pengfei could recruit about 10,000 more, but he did not have such a plan. At least, he had no plans for further expansion until he actually sent troops.

Li Pengfei knows very well a truth, that is, there are more soldiers than too many soldiers, and as long as he makes good use of these 5,500 cavalry, it will be enough for him to reap enough credit in the Yellow Turban Rebellion.

The Yellow Turban Rebellion was put down so quickly that it took only nine months from the outbreak in early February to its suppression in November.

And because of his status as a member of the party, he is still under the party ban, and he will not be able to send troops until the party ban is lifted after the court comes down in April, and the time to participate in the extermination is only seven months at most, or even shorter.

Because his accession is bound to change the course of quelling the rebellion.

In such a short time, the slow-moving infantry clearly did not fit into his plans.

After the cavalry was formed, a one-and-a-half-month vigorous large-scale military training operation began.