Rebirth of Military Workers

Chapter 568

“Don’t tell me, let’s go directly to Erzhong, otherwise it will be difficult to know the real situation.” Early the next morning, Zheng Yucheng and Xie Kai were going to Erzhong.

When setting out, Zheng Yucheng was about to inform Erzhong that he was stopped by Xie Kai.

“In fact, there is no need, they know we will come.” Zheng Yucheng knew Xie Kai’s purpose.

Erzhong is recasting now. Not only them, but many heavyweight players will come here, and even Minister Shen Hong will personally come here to sit here, in order to ensure the success of this casting and avoid scrapping.

Xie Kai still insisted.

Reluctantly, Zheng Yucheng borrowed a 212 Jeep from the power plant, and the two drove directly to Erzhong.

The power plant originally had a better car, but Xie Kai is more affectionate for this car. Zheng Yucheng has always liked this car. Even if the shock absorption effect is not good, he still drives such a car outside.

At the gate of Erzhong, people were notified to Erzhong’s outreach department.

After Jiang Ming and others found out, they hurried to the door to greet Zheng Yucheng and Xie Kai.

After some greetings, Zheng Yucheng went straight to the subject, “Director Jiang, how are your preparations for casting this time?”

“It’s ready. You guys came at the right time. I will start casting this afternoon. I just came from the foundry. Minister Shen and Director Tang are all in the workshop.” Jiang Ming saw the two of them drive over by themselves. Without anyone else, he hurriedly invited the two in.

Zheng Yucheng directly got into the car and drove to the foundry shop.

The entire foundry workshop is entirely a newly-built light steel structure workshop. In the open space outside the workshop, a black-brown cuboid casting is placed on the side like that, and the outside is badly rusted.

“This is the scrapped beam before. I don’t know how to deal with it now. Flame cutting is not easy…” The car parked beside the scrapped beam outside the foundry. Seeing Xie Kai staring at the thing, Jiang Ming hurriedly introduced it. .

Xie Kai walked over and looked at the thing next to it, the rusty casting, there was nothing to see.

“Is this roughing?”

“The large margins on the four sides have been removed with a gantry planer. The castings that have not been processed can not be tested for flaw detection. The previous casting was not very comprehensive when cooling, and the internal grain structure was very coarse…”

“The internal grain structure of the casting is coarse, which is normal.” From the surface, there are not many problems.

It’s just that there are irregular holes as big as thumbs in some places on the surface of the casting. This is the trachoma caused by casting defects.

In the middle position, this defect is more obvious.

After Xie Kai watched it, he didn’t say anything, and went straight into the foundry shop.

In the casting workshop, like a furnace, before entering the door, I felt a wave of heat rushing toward my face, and in an instant, sweat soaked the back of my clothes.

There are eight huge smelting furnaces on both sides of the entire workshop. Inside these smelting furnaces, the steel ingots in the furnace are melting.

In the center of the workshop, one person is tall, and huge sand casting molds are placed like this.

What surprised Xie Kai was that there was a shell around the mold, just like the ancient coffin had several layers. There is a lot of black carbon in the gap between the mold and the shell.

When the two entered, several people wearing safety helmets were holding drawings and pointing to the surrounding situation.

Xie Kai was puzzled.

He took the helmet that Jiang Ming handed over and put it on his head casually, and walked inward.

“When you are ready, you must prepare for the ignition. The entire mold must be heated evenly and the temperature must be the same.” Shen Hong, a technician wearing a safety helmet in his fifties, pointed to the drawing and introduced the situation to a few people around him. Said the minister.

“What’s the matter?” Xie Kai leaned forward, intending to figure out the situation, but he didn’t hear anything.

What should carbon be added to the middle mold?

“Are you here?” Shen Hong looked at Xie Kai with a smile on his face, “I heard that you were very good on the exam.”

“I didn’t pay attention, I used a little bit of effort, I didn’t expect this question to be so simple.” Xie Kai was not modest at all, looking at Chen Mingshan straight to one side, he thought about it when he ran to learn philosophy, Dean Chen Will he vomit blood?

Chen Mingshan was a bit awkward when Xie Kai saw him, thinking that there was something wrong with his appearance, and after checking for a long time, he didn’t find any problems.

But it’s not easy to ask.

“What is this for? Isn’t it for casting? What do you do with carbon?” Xie Kai asked, pointing to the mold next to him.

This mold is not small.

He also knows that when casting, the mold is prone to deformation at high temperatures, which has a great impact on the quality of the casting.

“Before, because the outside cooling of the casting was too fast, the internal heat dissipation was not good, so the internal grain structure was coarse…According to our analysis, when the molten steel touches the mold during the casting process, it will cause the joint to cool rapidly. …” Chu Guorong explained to Xie Kai.

“But if the heating temperature is too high, will it damage the sand mold and affect the entire casting?” Xie Kai frowned and asked.(Read more @ wuxiax.com)

Previously, it was because the cooling was too fast, so the quality of the entire large casting had a major defect.

Now want to reduce the cooling rate by heating outside the mold, which makes the whole process more difficult to control.

Once there is a problem with the process, it is absolutely scrapped.

The molten steel in the surrounding smelting furnaces has almost completely melted.

“For this casting, a team of hundreds of people has done dozens of experiments in the past few months, constantly improving the methods, and studying the timing of cooperation, only to come up with such a plan. The method is very earthy, but it works.” Shen Hong said, “Otherwise, you can only use larger forging equipment for forging, and then heat treatment, etc…”

“This is hundreds of tons, heat treatment…” Xie Kai felt terrified when he thought of the heat treatment of such a large part.

Heat treatment, but by heating the entire part, the internal metal crystal structure of the part becomes fine.

But for such a big one, it is too difficult to heat up and keep it warm for a long time.

Once the heating is uneven, it will eventually cause the entire product to be unevenly heated, and the internal metallographic structure will be very different. If the force is not large, the problem will not be too prominent.

However, the working pressure of the large press is 45,000 tons. The main beam not only has to withstand tens of thousands of tons of working pressure, but also needs to withstand the pressure of thousands of tons of parts and molds connected to the main beam.

The internal structure is inconsistent, and the final result is that the stress is concentrated in the coarse grain structure. These areas have very large grains and are constantly stressed. The accumulation of force will eventually cause the internal coarse grain structure to break away. Cracks occur, which leads to the final fracture…

“This process is equivalent to our quenching and tempering treatment. Ordinary castings are produced, cast in molds, and the molten steel inside is gradually cooled. This cooling process is actually from the outside in. The outside mold is in contact with the air and emits The heat is firstly cooled, and then the temperature of the molten steel inside is transferred out, and the temperature is gradually reduced… Therefore, in the casting process, the more the outer position, the finer the grain structure…” Chu Guorong went on to explain.

Xie Kai understands these theories.

The problem is that by controlling the temperature around the casting, can the current problems be solved?

“So, this time the cooling process of the entire casting will be prolonged?” Xie Kai somewhat understood why. “Is it useful to adopt such a soil method? The outside temperature and the inside temperature are both uncontrollable. Especially the temperature inside the casting…”

Because of understanding, knowing how difficult it is.

“It is not uncontrollable. According to our many experiments and calculations, the outside temperature is directly related to the internal temperature of the casting. In order to control this temperature, we have established a mathematical model. Once successful, whether it is used for other purposes There is no problem with any large castings!” Chen Mingshan said triumphantly, “After you come to our college, you will be able to come into contact with this set of mathematical models.”

He thought that this set of models would be very attractive to Xie Kai.

However, Xie Kai just looked at him and smiled.

“Although the method is soil, it involves a lot of things, so it took so long this time to start casting again.” Shen Hong, as the minister of industry who is like opening up, attaches great importance to this matter. “Slow down the cooling rate and try to maintain the same temperature between the inner center of the casting and the outside, which can refine the grain structure and improve the mechanical properties…”

He has presided over the design of nine major domestic complete sets of industrial equipment, and the degree of importance he attaches to large presses does not seem to be underestimated.

Xie Kai nodded, and said nothing.

The whole project is a very big challenge. There is no domestic precedent, and foreign experience cannot be used for reference. Such an approach is absolutely impossible to choose in the international community.

The result can only be known until the final casting is formed.

Even Minister Shen Hong and Chu Guorong and other big players, no one can guarantee that the current process will be successful.

Experience is accumulated.

Many things, even if you know the craftsmanship and the details are a little surprised, they will cause immeasurable effects.

“I hope there is no problem this time. Many of our projects are waiting for large presses.” Zheng Yucheng sighed and said worriedly, “According to the previous schedule, now the main beam has been processed and is ready to be installed.”

“This is something that can’t be helped. The previous considerations were not comprehensive enough. The tuition fees this time have been paid too much.” Minister Shen Hong was also a bit painful.

Double people are even more painful.

The scrapped one can be sold for hundreds of thousands of scrap iron. The production cost, electricity bills, molds, etc., are all paid for by them.

“Yes, but also because of funding issues, many of our production schedules have been seriously affected.” Jiang Ming looked at Zheng Yucheng and complained, “Director Zheng, you don’t know if you can…”

“Don’t even think about it. Our budget is only a large press. If you want to continue to take over the next 65,000 tons or 80,000 tons of large press construction plan, you will follow the contract. Besides, Yizhong will not be responsible for it. Loss?” Zheng Yucheng directly blocked Jiang Ming’s words.

This project is a joint venture between No. 1 Heavy Industry Co., Ltd., Erzhong Group and dozens of other state-owned units. A 45,000-ton die forging machine was built at a cost of 200 million yuan.

In China, it is already the largest project for a single device.

“First Heavy only undertakes part, and most of it is undertaken by Erzhong. Nowadays, Erzhong does not have a lot of business.” Shen Hong also spoke.

They hope 404 can afford part of the funding.

The difficulty of the whole project is too high, and there is no experience to learn from.

It is completely focused on the country’s largest force to tackle the problem, and the funding is much higher than the original budget.

“Minister Shen, if this continues, we won’t be able to cooperate in the future. No matter how we need it, we won’t be able to invest in big presses anymore.” Xie Kai said dissatisfiedly. It stands to reason that Shen Hong should not help the second-class unit to speak.

Shen Hong looked at Xie Kai with interest and did not speak.

Waiting for Xie Kai to continue.

“We invested in the construction of large presses, and each unit undertook business. In this process, we challenged their respective existing technical systems and practiced internal skills… In the end, the technology and everything were theirs… We purchased the large presses and gave them. Sufficient costs, the excess costs incurred during their own experiments, if they were borne by us, would not conform to the principles of market economy…” Xie Kai said.

The meaning is very clear, each unit takes the construction funds of 404 to upgrade its own technical level, and ultimately causes losses in the process due to its own reasons, and it is impossible to pay for 404.

The 404 funds cannot be used to support the development of the entire system.

The improvement of the technical level has to be borne individually, and 404 is only the purchaser.

“In addition, according to what we know, the units that undertake each core component and system are subsidized by the Ministry of Finance, right?” Zheng Yucheng asked.

It’s hard to talk about a group of people.

The large-scale press project was eventually dismantled because of its poor technical level, huge capital needs and shortage of national funds.

404 paid the money and picked up this project. The state did not spend a penny, but used project subsidies to provide funding for each core unit.

Equivalent to the same project, the participating units received two grants.

“The state subsidies not much.” Jiang Ming said.

“We spent 200 million yuan on this project, and the state didn’t give a penny subsidy!” Zheng Yucheng said dissatisfiedly. “This equipment is not for our family.”

“Okay, Comrade Yucheng, we all have difficulties. Let’s understand each other. It’s almost time, let’s get ready to warm up.” Shen Hong hurriedly persuaded everyone to fall out.

The 404 system is very dissatisfied with the delay in the progress of the large press.

But the main beam of the entire big press is the key.

The column used to support the entire weight adopts the use of steel wire winding pre-stressed buckling technology that Xie Kai said, making the project easier.

The 45,000-ton press is even just a chance to practice!

“Is it starting now?” Xie Kai asked, “Has the molten steel in the furnace melted?”

“It’s been prepared long ago. It will take a long time for the temperature of the mold to rise.” Chu Guorong said.

With an ignition command issued, the natural gas flame used for ignition began to burst into the carbon groove around the mold…