After finishing the official reception and reception, Li Zhi began to study crucible steelmaking.
Although the quality of Su Steel is good and meets the standards of ordinary steel in later generations, it still contains a considerable amount of sulfur and phosphorus, making it difficult to use as tool steel. Moreover, Su Steel is expensive, with a pound of Su Steel costing two to five taels of silver.
The cost of making bayonets is very high. Li Zhi now has 8,000 rifles in service and 2,000 rifles in stock. The cost of Soviet steel for these 10,000 rifle bayonets reaches 25,000 taels of silver. If Li Zhi wants to expand his troops
, but also spend more money to buy Su Gang.
In addition, Li Zhi also needs high-quality steel to make the main spring and buckle spring of the flintlock bolt. The quality of the steel is the key to determining the effect of these two springs, which directly determines the firing rate of the rifle. Currently, the firing rate of rifles made with Su Steel is in
More than 80%. If the firing rate is further improved, the shooting hit rate can also be improved to a certain extent.
Finally, good steel can bring huge profits to Li Zhi. Su Steel sells it to the north for two to five yuan per catty. If Li Zhi sells better steel at a slightly lower price, he can seize a lot of Su Steel's market.
The profits are huge.
You must know that in this era, fine steel is extremely scarce and can even be used as its equivalent. Some wealthy families will hoard some fine steel to prepare for emergencies. If Li Zhi refines good steel, there will be a market.
Li Zhi urgently needed better and cheaper high-quality steel, and the crucible steelmaking that appeared in the mid-18th century was undoubtedly the only option available to Li Zhi. This steelmaking method used wrought iron as raw material and graphite as the crucible carburizing material.
and reducing agent, using limestone as a slagging agent, and the quality of the steel produced is very good. This steelmaking method has been used in history for a century, and was not replaced until the invention of electric arc furnace steelmaking at the end of the 19th century.
As an eighteenth-century technology, the crucible steelmaking method is relatively simple. Li Zhi studied some indigenous crucible steelmaking methods before traveling through time, and he just happened to use them now.
The difficulty in making steel in a crucible is that it requires a temperature of 1,600 degrees. Li Zhi found Cai Huaishui and asked him to be responsible for purchasing a crucible that could withstand such a high temperature.
Cai Huaishui now earns forty taels a month, is married to Cui'er, and just gave birth to a fat son last month. Forty taels of silver is enough for a family of five to live a well-off life these days, not to mention that Cai Huaishui works in a glass workshop.
Yaotou is still responsible for three meals a day. Although he was kicked out of the house by his father, he did not starve to death outside, but lived a life full of life. He is now very satisfied with his life in Fanjiazhuang and is grateful for the people who brought him this life.
Li Zhi is also quite loyal.
"Cai Huaishui, I need a crucible with a higher temperature than burning glass. Do you know where to get one?"
Cai Huaishui thought for a while and said: "Sir, it is possible to make a crucible that can be heated to such a high temperature. Then we have to use black talc as a crucible. There are not many black talc minerals. It can make a crucible as big as a rice bowl and four inches deep."
It costs two taels of silver. There are people in Texas who use such crucibles to make porcelain, so you can buy it there."
Li Zhi thought for a moment and guessed that the black talc Cai Huaishui mentioned was probably graphite, and said, "Would it be cheaper to make a crucible with half black talc and half clay?"
"That crucible also costs one, two, three cents of silver."
Li Zhi did the math and felt that the crucible Cai Huaishui mentioned could hold at least ten kilograms of steel. In this way, the cost of steelmaking in the crucible was much cheaper than buying Suzhou Steel. Li Zhi nodded and said: "It doesn't matter, then you can contact us to buy this
Buy a hundred crucibles first. If I use the crucible you bought to make steel, I will reward you twenty taels of silver."
Cai Huaishui was overjoyed when he heard this and said: "My boss will lend me three servants, four horses and two carriages, and I will take people to Texas to buy a black talc crucible."
Cai Huaishui set out for Texas that day, and returned six days later with a carriage transporting a hundred crucibles.
Li Zhi took a closer look at the crucible and found that it was indeed made of graphite and clay.
With the crucible in hand, Li Zhi began to build a crucible steel-making furnace. This kind of furnace was made of refractory bricks, with a hollow bottom. There was a blast port next to the cavity, and the air was continuously blown by manpower. There were iron bars in the middle of the furnace.
The furnace bridge is completed. The furnace bridge is filled with coke, and a graphite crucible is placed in the middle of the coke. There is a hole on the furnace cover. This hole is used to observe the molten iron and stir the molten iron.
Five crucibles can be placed in this furnace.
Coke was used for steelmaking in the late Ming Dynasty. Li Zhi sent people to search around Tianjin, found a coking workshop near the official steelmaking plant in Zunhua, and bought coke.
It took three days to complete the furnace, and Li Zhi began to experiment with steelmaking.
Li Zhi piled up the coke in the furnace, placed wood under the coke, ignited the wood, and gradually burned the coke. At this time, he did not put the crucible into the furnace. He waited for half an hour to heat up the crucible before putting it in the furnace.
Put the empty crucible in. Then blow the material hard to make the crucible hot, then put the preheated wrought iron into the crucible.
At the same time, put some lime powder in the wrought iron to make slag.
Turn off the furnace and burn for a few hours, wait for the graphite material in the furnace to penetrate into the molten iron, and turn the molten iron into molten steel. Then open the furnace and scoop out the slag floating on the molten steel, and then pour out the molten steel. Let the molten steel turn into steel ingots in the mold.
, the required steel was obtained.
Li Zhi didn't know how many hours it would take to burn the carburizing completely, so he tried it several times. When refining steel, the crucibles were used repeatedly, and one of the crucibles cracked on the fifth use. The molten iron leaked out.
The entire stove was destroyed, but fortunately it didn't leak out of the stove and hurt Li Zhi.
It seems that this graphite crucible can only be reused three or four times. From then on, Li Zhi threw away all the crucibles that had been used three times and no longer used them.
After finally burning molten iron in more than a dozen crucibles, Li Zhi found that burning it for two and a half hours was more suitable for carburizing, and the result was steel.
But after the first furnace of molten steel was fired, the effect was not good. Li Zhi asked the blacksmith to make a spring from the steel. As a result, the elasticity of the spring weakened after being pressed more than ten times. Obviously, the steel produced this time was not up to standard.
Li Zhi guessed that the steel contained too much phosphorus and sulfur, especially the phosphorus content was too high. Phosphorus and iron formed an extremely brittle compound, ferric phosphide, which caused the plasticity and toughness of the steel to drop sharply at room temperature.
Li Zhi tried again. This time he waited for the molten iron to be burned and then added more limestone, fluorite, river sand and soda ash to the crucible to make slag. Then he kept stirring the molten iron with an iron rod during the refining process, hoping to remove more sulfur.
and phosphorus.
The quality of the steel smelted in this crucible has been significantly improved, and the springs made are comparable to Suzhou Iron and Steel products. But Li Zhi is still not satisfied. The products made by steelmaking in the crucible should be stronger than Suzhou Iron and Steel Co., Ltd. Obviously the production process can be improved.
