my scientific age

Chapter 327 Serious Steel!

The fiery red high-temperature molten iron came into contact with the scrap steel, surging and splashing like an ocean wave, boiling violently. The workers who stayed outside the safe area in front of the furnace only felt a rush of heat, covering their whole bodies.

This is the fiery heat of steel.

The vast majority of scrap steel used in the base area comes from acquisitions. In the name of Taihang Industrial Company, scrap steel was purchased at a high price, and a scrap metal recycling industry chain similar to later generations was established in Shaanxi and Shanxi. The common people are very happy to sell all kinds of scrap steel to Taihang Industrial Company.

As for how the scrap came from...

Heroes do not ask where they come from, and scrap steel does not ask where they came from.

With the scrap steel acquisition industry chain established by Taihang Industrial Company, the electric furnace steel plant in the base area has a steady supply of scrap steel, and the current test furnace scrap supply is also the same.

Of course, as long as the first smelting test is successful, a positive circulation system for the supply of steel ingots can be established to get rid of the situation that the supply of scrap steel is completely dependent on external purchases.

"Stop the injection of molten iron, and add the main slag and mixed flux." When the molten iron in the converter reaches the limit value, and the total amount of molten iron charged is about 70%, Yu Hua, who is standing in the main control room to observe all the time, immediately gives a new instruction.

Sun Hong, a crane worker who received the order, stopped pouring molten iron, placed the iron ladle in a limited area, and then lifted the funnel containing the slag-forming material and mixed solvent to the top of the converter, opened the bottom funnel, and added slag.

The main slag is limestone, and the mixed solvent is raw dolomite and fluorite.

The former is used for dephosphorization and desulfurization, and it is the main slag-forming agent in the converter steelmaking method. .

The splash of molten steel is no joke. If you are not careful, it may cause fatal production accidents.

The three auxiliary metallurgical materials have been tested time and time again by countless scientists in the metallurgical field, costing countless funds and efforts, and even the price of blood.

With the addition of three slagging raw materials into the converter, the inside of the furnace body changes suddenly. Under the action of high temperature and flux, limestone is mixed with molten iron and continuously absorbs sulfur and phosphorus elements.

In the whole iron and steel smelting process, silicon and carbon are exothermic elements, and manganese is a beneficial element, which can be reduced in molten steel or increased to smelt high-manganese steel. Phosphorus and sulfur are harmful elements, and must be as much as possible. Remove or reduce its ingredient content.

The main harm of phosphorus is to reduce the plasticity and toughness of steel, making it appear cold brittle, while the main harm of sulfur is to increase the hot brittleness of steel.

"The furnace body rotates vertically, the air separator supplies oxygen, and the oxygen lance is at a high position." Seeing this, Yu Hua turned his head and ordered the two operators in the main control room.

There are two consoles in the main control room, one is responsible for the converter and the other is responsible for the oxygen lance. The entire test furnace has formal operating qualifications, including three people including Yu Hua.

Generally speaking, the height between the nozzle of the oxygen lance and the surface of the liquid molten pool of the converter is divided into three parts: high, medium and low, and the blowing effect is different. Second slag, according to the different slag-making methods to formulate the gun position configuration.

Slag making is divided into single slag method and double slag method. The single slag method usually only produces slag once in the smelting process, and the gun position is selected to be high + medium combination.

The double slag method, as the name suggests, produces slag twice in the smelting process. The gun position is first used high + medium, and then low + medium. The smelting process is complicated, and it is usually used for the smelting of silicon steel and gun steel.

For the first smelting test, the single-slag method was selected, and the double-slag method was not used for the time being.

After receiving Yu Hua's order, the young converter operator who had undergone extensive selection and strict training nodded, with a serious face, clenched the joystick with both hands, and slowly pushed it forward, making the converter return to [-] degrees at a rotation speed of about two degrees per second. vertical angle.

"Boom!" At the same time, the air separation equipment in the idle state of the lowest power gradually increased to the highest power, operated at full load, and fully supplied pure oxygen to the test furnace.

Here, with the converter vertically facing the oxygen lance above, the young operator controls the oxygen lance to rise to the highest position, and the three-hole nozzle is aimed at the inside of a fiery red converter. When the working oxygen pressure displayed by the barometer reaches 8 standard atmospheres, Immediately press the oxygen supply button.

In an instant, a sharp and high-frequency sound resounded through the factory building and entered everyone's ears.

The high-pressure pure oxygen moves forward at a high speed in the metal pipe, reaching the speed of sound in an instant, and reaches the nozzle of the Laval nozzle structure across a short distance of a few meters. An order of magnitude improvement, from a few hundred meters per second to several kilometers per second.

Go forward, strike!
The three oxygen streams pierce the converter like a long sword and blow on the surface of the molten iron. The pure oxygen and the high-temperature molten iron produce the most violent and direct oxidation reaction, and the temperature of the molten iron increases rapidly.

The main heat source of the oxygen converter steelmaking method basically comes from the physical heat and chemical heat of the molten iron into the furnace. Around Celsius, no additional heat needs to be supplied, so that energy can be saved.

Compared with the current mainstream open hearth steelmaking in the world's industrial countries, the leading technology of oxygen blown furnace steelmaking is not only the output.

In the test furnace, the chemical composition of molten iron in the early stage of blowing is constantly changing. Silicon and oxygen generate silicon dioxide, which releases a high amount of chemical heat. The content of silicon in molten iron decreases at a speed visible to the naked eye. When the slag material accelerates the melting of the slag, a thin layer of highly alkaline slag is formed on the surface of the molten iron.

Starting with this layer of slag, the impurity elements in the molten iron seem to find a home, quickly approach and condense, and the thickness of the slag increases.

Time passed slowly, and after 2 minutes, with the silicon in the molten iron reduced to the lowest level, manganese and phosphorus successively entered the high-temperature oxidation exothermic stage, which further increased the temperature of the molten iron and controlled the temperature of the molten pool at about 1550 degrees Celsius.

At this point, the whole blowing process has come to the middle stage.

Now, impurity elements such as silicon, manganese, phosphorus and sulfur in molten iron have been converted into high-quality slag under the action of high temperature, slag, and flux.

The quality of slag can objectively reflect the quality and cleanliness of molten steel. In a sense, steelmaking is continuous slag.

"Down to the middle gun position, the cold circulation power reaches the highest, and the molten iron is rapidly decarburized."

In the main control room, Yu Hua raised his right hand, looked at the time displayed on the watch, 10 minutes had passed, and then gave instructions to the oxygen gun operator.

According to the dynamic mathematical model of molten steel smelting in the test furnace constructed by Yu Hua, after 10 minutes of blowing, the internal chemical impurities have been converted into slag, and what needs to be done now is to convert the molten iron into molten steel!

Iron becomes steel, and the core lies in carbon content.

Steels with a carbon content of less than 0.25% are called low carbon steels, have lower mechanical properties, and are generally referred to as 'mild steels'.

Carbon content in the range of 0.25% - 0.65% is called medium carbon steel, which has good mechanical properties and chemical properties. It is mainly used in various mechanical parts, gun barrel steel, gun steel, armor steel and other specialties required for the production of military industry. The steel is based on the extension and improvement of the medium carbon steel frame, adding various beneficial elements to improve the mechanical properties of the material, such as manganese, nickel, tungsten, chromium, molybdenum, vanadium, etc., and become the alloy steel and structural steel that people often say.

In addition, silicon steel, known as the steel aristocracy, also belongs to the medium carbon steel frame.

Carbon content in the range of 0.6% - 1.7% is called high carbon steel, which is often called tool steel in the industry. It has excellent mechanical and chemical properties, but low toughness and plasticity. It is usually used as metal cutting tools, such as car Knives, milling cutters, reamers, boring tools, etc.

Of course, like medium carbon steel, adding various beneficial elements can make it high carbon alloy steel, such as high carbon tungsten steel, high carbon manganese steel and so on.

The target selected for the first smelting test is the most widely used medium carbon steel.

"Yes!"

The young oxygen lance operator nodded immediately and controlled the descending height of the oxygen lance nozzle. Due to the lack of real-time observation equipment in the furnace, the specific position of the oxygen lance nozzle can only be estimated artificially by the descending rate of the console. standard.

Very informal, but better than practical.

After all, Rome was not built in a day. The supporting facilities and instruments of these steel plants can only be owned by developing step by step.

In fact, in addition to the inability to accurately control the height of the nozzle of the oxygen lance, there are also problems such as the inability to dynamically and accurately measure the composition and carbon content of molten steel. Dynamic and accurate measurement can grasp the composition and carbon content of molten steel anytime, anywhere. Then add it, if there is more of a certain element, then reduce it, so as to achieve the goal of smelting exclusive steel.

However, the test furnace does not yet have this condition. The first smelting test completely relies on the calculation data of the molten steel smelting mathematical model constructed by Yu Hua. If the gap between the mathematical model and reality is far, it means that the test fails.

Here, the oxygen lance operator calculated the descending rate in his mind, felt that the nozzle had almost descended to the height of the mid-lance position, and then pressed the pause switch.

Above the converter, the oxygen lance nozzle with an error of about five centimeters from the middle gun position continuously sprays pure oxygen in a hypersonic state, and impacts the molten iron in the molten pool with a higher impact force, causing it to tumble and stir, and enter the stage of rapid decarburization.

Under the impact of pure oxygen, molten iron in the molten pool surges in a rapid clockwise motion, and the carbon elements inside continuously generate carbon monoxide and carbon dioxide.

Stuffed on the Pearl Yulin, for the first time there is a taste of heavy industry.

It's pollution and it's...

hope!

……

After 5 minutes, the temperature in the molten pool in the rapid decarburization stage reached 1600 degrees Celsius, and the carbon content of the molten iron continued to decline, eventually breaking through the key node of 2%.

Now, molten iron turns into molten steel.

But not enough!

Yu Hua's face was calm, his eyes were fixed on the converter, the computer started thinking in his mind, and more than 70% of the computing resources were used to continuously deduce the mathematical model of molten steel smelting.

1.5% carbon content, high carbon steel range.

1.3% carbon content, high carbon steel range.

0.8% carbon content, high carbon steel range.

0.59% carbon content, into medium carbon steel.

"Stop supplying oxygen!" The carbon content of molten steel in his mind reached 0.55%, and in a flash, Yu Hua, who raised his right hand high, suddenly lowered it and gave instructions to the oxygen gun operator.

The oxygen lance operator, who was already ready, pressed the switch without hesitation to turn off the oxygen supply.

"Boom!" The sharp roaring sound of extremely penetrating power disappeared when the oxygen lance was supplying oxygen, and the workshop suddenly fell into a brief silence, except for the tumbling of molten steel in the converter and the sound of the air separator running.

The workers and soldiers who stayed around were stunned for a while, but they immediately reacted and understood what had happened.

The most important moment has come!
"The furnace body is tilted, the slag ball is ready, and the molten steel is tapped." Yu Hua did not delay, raised his hand to check the time, and issued new orders to the converter operator and each production team.

The carbon content data of the mathematical model of molten steel smelting is finally set at 0.55%, and the mechanical properties and chemical properties are more than 20% better than those of the electric furnace steel produced by the electric furnace steel plant, which can fully meet the requirements of the horizontal bar diesel engine piston, crankshaft, gear and low-bore pressure percussion barrel. .

Of course, this is the result of the simulation calculation, and the actual error value is not clear. Yu Hua hopes that the error value can be less than 1%.

The total smelting time is 33 minutes, and now, the molten steel is tapped and the original ingot is cast.

Yang Zhi and a group of Red Army soldiers stared at the test furnace. The ladle, commonly known as 'ladle', came to the tap, and was filled with a deoxidizer. At the same time, the converter operator controlled the tilting angle of the furnace body, and the slag ball device entered. ready state.

The slag ball device mainly prevents a large amount of mixing of steel slag and molten steel. It was designed by the Japanese metallurgical industry in the 70s. The structure is a sphere composed of dolomite and iron core. The technical content is average and the design is extremely delicate. The design is used.

At this moment, everyone held their breaths, not even daring to breathe.

The metal baffle of the steel outlet opened, and a group of red flames burst out like an explosion, churning upwards with great momentum, and before everyone could react, just one second later, hot and scalding molten steel quickly flowed along the groove. , into the ladle directly below.

"Come out, molten steel is out!" Watching this scene, the workers and soldiers who were closest to each other burst into tears, and couldn't help calling from the deepest part of their hearts.

The molten steel, symbolizing the molten steel of the future, is quietly born in a historic moment.

Looking at the continuous flow of molten steel, everyone present seemed to be possessed, and all fell into a state of obsession. An inexplicable feeling surged from the depths of their souls and spread throughout the body. Far more attractive than any peerless beauty.

It's so powerful, it's so beautiful...

As soon as the news of the molten steel came out, it swept everyone in Sancha Bay like a blockbuster, and the entire Sancha Bay instantly boiled. Countless Military Industry Bureau workers and soldiers of the First Red Division were very excited and celebrated the moment in their own ways.

1937年8月3日上午10：20分，世界上由氧气顶吹转炉冶炼的第一炉钢水诞生，地点——中华陕北榆林三岔湾。

"Add the slag blocking ball and prepare the round ingot mold." Yu Hua's face was calm and calm, and he didn't care about the emotions of the surrounding workers and soldiers. Looking through the furnace mouth, the molten pool in the furnace had been reduced by three-quarters, and continued.

The release of molten steel is worth celebrating, but anyone can celebrate, but he can't.

The first smelting test is not over yet.

The chief dispatcher nodded, waved the flag quickly, and conveyed their respective instructions to the slag ball production team and the molten steel casting production team.

Soon, the slag blocking ball with a diameter of 8 cm was placed above the tap hole of the converter to resist the surrounding slag. At the same time, the molten steel casting production team on standby was busy immediately to check whether there was any problem with the round ingot mold.

The inner diameter of the round ingot mold is 80 mm and the length is 2.4 meters. There are [-] sets in total. The ingots are connected in parallel to improve the pouring efficiency. After the pouring of these round ingots, they will be sent to Liushugou Industrial Zone for tempering, forging and rolling. The seam steel pipe, after a series of treatments, becomes a qualified standard mortar pipe blank.

After a few minutes, the molten steel was poured, and the ladle containing two tons of bright yellow molten steel was slowly lifted by a ten-ton crane, left the converter, and came over the pouring area.

The reorganization and pouring team kept communicating and contacting, the ladle gradually lowered its height and came to the top of the pouring gate. The angle was inclined, and the nozzle was aligned. In an instant, molten steel with a temperature of up to [-] degrees Celsius flowed out and entered a circle along the pouring gate. inside the ingot mold.

Two tons of molten steel was poured, and the scene was extremely spectacular. Ninety sets of round ingot molds ignited billowing flames, and the internal molten steel entered the cooling stage.

"Deputy Team Leader Yu, what are we going to do next?" Yang Zhi, who was also in the main control room, asked curiously when he saw the scene in the pouring area below.

When Yu Hua heard this, he responded with a smile: "When the real test results show that steel is smelted, then the first smelting test is passed, and a 24-hour trial production is carried out. If the smelted iron is then declared a failure, find out the problem and correct it. "

Although Yu Hua is very clear that what is smelted is steel, he must maintain the most basic rigor before the official test results are released.

"So that's the case, then what we've made must be steel." Yang Zhi nodded, staring at the ninety sets of round ingot molds in the pouring area, whispering softly, full of expectations.

Calculated based on the length of each mold of 360 meters, one round steel ingot can produce four mortar barrels, and the round ingot here can theoretically produce [-] ​​barrels.

360 barrels, in a sense, this is 360 mortars!
After the joy of the first batch of molten steel flowing out of the workshop, they fell into a wait full of anticipation again. Everyone's eyes were focused on the cooling round ingot mold, and they understood that the quality of these finished products ultimately determines whether the first smelting test is successful.

Is it steel?

Or iron?
The molten steel in the round ingot mold is cooled and crystallized, gradually forming crystal grains. After a few hours, it is time to demould. With the opening of the first round ingot mold, the fiery red round ingot comes into view, responsible for the final test result detection Two of the workers came forward with a sledgehammer and carried out the simplest quality inspection on the flaming red round ingot.

In this era, the easiest way to detect whether it is steel or iron is - smash it!

Pig iron will crumble and steel will deform.

"Dong dong dong!" The sledgehammer slammed on the surface of the round ingot, and a dull and powerful sound came out. The surface of the fiery red round ingot was slightly deformed, and the iron oxide in an irregular shape was scattered, and the round ingot body did not appear any collapse phenomenon. .

One hammer is not enough to conclude the coffin. The two workers vigorously swung the sledgehammer under everyone's attention, hammering the round ingot again and again.

Looking at the surface of the round ingot being hammered, the surrounding soldiers and workers tried their best to remain silent and disciplined, but it didn't take long for them to hold back their emotions.

It's steel!
Serious steel!

(End of this chapter)