industrial overlord

Chapter 517 Molten Steel Galloping
Leaving aside Yang Wenjun's plot against Jin Xuanxun, let's turn our attention back to the Hanhua heavy factory area in Xunyang.

In the spacious foundry, four huge ladles have been hoisted into place by the casting crane, waiting for the order to open the ladle and pour.In these four ladles, there are more than 500 tons of hot molten steel, and workers will use these molten steel to cast the first beam of the 1.5-ton hydraulic press.

"Master Li, it's up to you to succeed or fail." Lin Zhenhua stood beside the old stylist Li Genyuan and said to him with a smile.

Everyone in the workshop was at their respective positions, nervously preparing for the arrival of the last moment. The only two idlers were Lin Zhenhua and Li Genyuan.As the chairman of the group, Lin Zhenhua naturally didn't need to do the operation himself.Li Genyuan is the honorary commander-in-chief of casting modeling appointed by Lin Zhenhua. He has been busy with dozens of modeling workers for more than a month before, and now he can finally take a rest.The casting process was very tense. At Li Genyuan's age, he couldn't adapt to such a rhythm, so he could only stand aside and be an audience.

"Mr. Lin, I'm sweating in my hands right now. I've never made such a large casting," Li Genyuan said.

Lin Zhenhua said: "Master Li, don't worry, Liu Gong, Zhang Gong, and Xiao Zhen have already counted them many times, and there will be no problem."

Li Genyuan smiled embarrassedly: "Well, when you get old, you lose your courage. Speaking of which, the pouring plan has also been reviewed by Mr. Lin. It must be fine."

"Uh... I'm not particularly good at this." Lin Zhenhua began to pretend to be modest.

Speaking of which, the casting process of the casting that is about to start is indeed racking people's brains.Because of the production of chemical equipment, Hanhua Heavy Industry often has to manufacture some large castings, but in the past, the largest castings cast were only more than a hundred tons in weight.This time, what they manufactured was the upper beam of a 1.5-ton hydraulic press. According to Zhang Yuquan's suggestion, the entire beam adopted an integrated design, which meant that a component weighing more than 300 tons would be directly cast at one time.

The benefits of the integrated design of the crossbeam are very obvious. Since there is no need for joints such as welding or solid nuts, the structure of the crossbeam will be more stable and can withstand repeated impacts of 1.5 tons of forging pressure.However, the challenge brought by this design is also very severe, that is, Hanhua Heavy Industry must overcome the casting process of super-large castings.

The casting process is very simple to say. It is probably to first create a wooden mold that is exactly the same as the casting, and then bury the wooden mold with special molding sand to fill every gap.This kind of molding sand must be able to withstand the high temperature of thousands of degrees to the molten steel, and it must also have sufficient strength so that it will not deform under the impact of the molten steel.After the molding sand is filled, the molder will remove the wooden mold, thus leaving a molding cavity.When casting, molten steel is directly injected into the cavity, and after cooling and solidifying, the molding sand is removed, and the casting is completed.

For small castings, this process is not too difficult, but with the enlargement of castings, many problems that were not originally obstacles appeared.

The first is the so-called "floating core" problem. The casting is not a complete iron mound, but has various cavities in the middle. These cavities must be filled with sand molds before casting.During casting, molten steel is poured into the sand mold, completely submerging these sand cores at the center of the casting.Because the specific gravity of molding sand is much smaller than that of molten steel, under the submersion of molten steel, these molding sands will generate huge buoyancy, and may leave their original position and float to the surface of molten steel.Once this floating core phenomenon occurs, the entire casting process is considered a failure.

In order to solve this problem, Hanhua's sculptors thought of countless ways to connect individual sand cores with steel bars, and even reinforced them with steel plates to transmit the buoyancy of molten steel.A group of technicians including Zhang Yuquan, Liu Zhaohua, and Donnie Yen used computers to calculate over and over again to ensure that core drift would not occur during pouring.

After overcoming this obstacle, another bigger problem emerged, that is, the venting of the sand mold during the casting process.

Casting is a high-temperature operation. The temperature of molten steel is as high as 1500 degrees. Under such a high temperature, physical and chemical changes will occur in the molding materials, resulting in a large amount of gas.If these gases cannot be discharged in time and stay in the cavity, a huge pressure will be formed, which will cause an explosion.

The exhaust of small castings is very easy. It is enough to directly open a few exhaust ports on the sand mold. However, such a large casting weighing hundreds of tons has a length, width and height of several meters to more than ten meters, and the gas formed is huge. , the traditional exhaust method is difficult to ensure that all the gas is discharged in a short period of time.

In order to design this exhaust system, several Hanhua engineers struggled for a month or two, but they couldn't come up with a safe and reliable solution.Therefore, Lin Zhenhua called on everyone to work together and invited Li Genyuan, an old stylist who had retired for many years, from Hunbei to participate in the research.In the end, it was actually Li Genyuan's proposal that made everyone overwhelmed, that is, to break the previous practice of only opening the exhaust port above the sand mold, and adopt a two-way exhaust method.

Once this plan is broken, it will appear very common.The difficulty of exhausting large castings is mainly due to their large volume, but if the exhaust is exhausted up and down at the same time, it is equivalent to reducing the exhaust distance by half, and the difficulty is naturally greatly reduced.It is actually very easy to exhaust the air below, as long as some exhaust grooves are dug on the ground.

There is another small episode here, that is, after hearing Li Genyuan's proposal of the two-way exhaust, Donnie Yen was depressed for a week.He realized that he was a returnee studying in the United States in vain. On this kind of issue, he was actually not as rich as an old worker's imagination.

In fact, it is no wonder that people with greater knowledge often have more confinement in their minds, and it is easier to think about problems from some rules.However, some veteran workers who have worked hard in practice are very accustomed to taking the edge of the sword and using some unconventional methods to solve problems.

Donnie Yen now has a deeper understanding of what Lin Zhenhua once told him to learn from the workers.What he learned in this psychological setback can be said to be useful for a lifetime.

It is easy to come up with the idea of ​​two-way exhaust, but how to arrange the two-way exhaust pipes and determine whether the two-way exhaust can finally solve the exhaust problem still requires engineers to use scientific methods to calculate.Donnie Yen made use of his overseas returnee expertise to directly build a large-scale model on the computer, and conducted mathematical simulations on the gas production rate, gas production rate, discharge rate, etc. of the sand mold, and finally came to a conclusion that this plan was foolproof.

At that time, because the application of computers was not common enough, large-scale mathematical simulation was still a relatively new knowledge, and Liu Zhaohua and others were not proficient in it.However, Lin Zhenhua, as a traveler from later generations, is very familiar with this technology.He reviewed the entire simulation program done by Donnie Yen, and re-run it several times on the computer himself, so he was relieved.He was able to stand at the casting site and chat with Li Genyuan so easily at this time, also because of his confidence in the entire calculation process.

"Everyone, let's get started!"

With a command, the oxygen burning tube accurately aligned with the eight eyes of the four ladles, a string of dazzling sparks flashed, the eyes of the ladle were opened, and the molten steel poured down along the eyes. Inject into the sand box.The sand mold ejected blue flames several meters high at high temperature, and all the vent holes whistled like a whistle almost at the same time, and white steam spewed out, covering the entire workshop.

Zhang Yuquan, Liu Zhaohua, Donnie Yen and others stood in command positions and watched the whole casting process nervously.Donnie Yen held a laptop in his hand, looked at the data on it, and muttered something.Zhang Yuquan, on the other hand, stared intently at the surroundings of the molding box, as if he was estimating the displacement with his naked eyes, and was ready to issue an order to adjust the pouring speed at any time.

It was just 7 minutes, but everyone felt like a century had passed.

"Beep!" A whistle sounded, announcing the completion of the entire pouring process. After a short moment of astonishment, the people in the workshop erupted in joy:
"Success!"

"Victory!"

Everyone expressed their inner joy in various ways. The younger workers waved their fists, while the older and prudent workers shook hands affectionately with their colleagues. The hearts of all the people who had been hanging for many days finally All let go.

"Master Li, practice has shown that the upper and lower exhaust systems you designed are completely effective." Lin Zhenhua said to Li Genyuan, "Look, the lower exhaust system emits more gas than the upper exhaust system."

"It's all thanks to Mr. Lin daring to make up his mind. I am an ordinary worker, how dare I take this responsibility." Li Genyuan was so happy that his beard shook, and he replied to Lin Zhenhua.

Lin Zhenhua said: "This is still a good saying. An old family is like a treasure. This time we cast the beam of the hydraulic press, from the design of the exhaust system, to the impact of the sand, to the molding, all thanks to Master Li for your guidance. You These old workers are the most precious wealth of our country."

Li Genyuan smiled and said: "Haha, Mr. Lin is over the award. My old man has been doing modeling all his life, and he is dying. Being able to cast such a large piece of more than 300 tons is worth it in this life."

Lin Zhenhua said: "Master Li is too pessimistic. We still have large castings in the future. Our 1.5-ton hydraulic press is prepared for the forging of those large workpieces. When the time comes, you are ready to show your skills."

"With Mr. Lin's words, my old man will be young again. Mr. Lin, it's a pleasure to work with you!"

"Master Li, this is not my credit, but you have caught up with the good time. Chinese industry is going to the world, and we in the industry have a lot of opportunities to do things happily."

　The description of the beam casting process of the hydraulic press in this chapter is drawn from "The Link of Destiny - China First Heavy Industry Independently Developed my country's First [-]-ton Free Forging Hydraulic Press" compiled by Han Zhibin. Kudos to the technicians.

　　
　
(End of this chapter)