"Don't talk about it first, let's go to the second level directly, otherwise it will be difficult to know the real situation." Early the next morning, Zheng Yucheng and Xie Kai were preparing to set off for the second level.

When leaving, Zheng Yucheng was about to notify the second session, but was stopped by Xie Kai.

"Actually there is no need. They know we will come." Zheng Yucheng knew Xie Kai's purpose.

The second re-cast is now re-cast. Not only them, but many heavyweights will come here, and even Minister Chen Hong will come here in person to ensure that the casting is successful and avoid scrapping again.

Xie Kai still insisted.

Zheng Yucheng had no choice but to borrow a 212 Jeep from the power plant, and the two drove directly to the Second Cross.

The power plant originally had better cars, but Xie Kai has a lot of feelings for this kind of car. Zheng Yucheng has always liked this car. Even if the shock absorption and other effects are not good, he still drives such cars outside.

Only when I arrived at the gate of the second chapter did I let someone notify the second chapter of the external relations department.

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

After some greetings, Zheng Yucheng went straight to the point, "Director Jiang, how are you preparing for this casting?"

"It's ready. You are here at the right time. I'll start casting this afternoon. I've just come from the casting workshop. Minister Shen, Director Tang and others are all in the workshop." Jiang Ming saw that the two of them were driving over by themselves, and did not bring anyone else, so he hurriedly invited them in.

Zheng Yucheng got into the car and drove to the casting workshop.

The entire casting workshop is completely a newly built light steel structure factory. On the open space outside the factory, a black-brown rectangular casting on the side was placed on the side, and the outside was greatly rusted.

"This is the scrapped beam that was used to be. Now I don't know how to deal with it. It's not easy to cut flames or something..." The car stopped beside the scrapped beam outside the casting workshop. Seeing Xie Kai staring at this thing, Jiang Ming hurriedly introduced.

Xie Kai walked over and observed the thing next to him. The rusty castings were so rusty that they couldn't see anything at all.

“Is this roughing done?”

"The large margin of all four sides was removed with the gantry planer. The castings that had not been processed were not processed and could not be tested for flaw detection. The previous casting was not considered very comprehensive when cooling, and the internal grain structure was very thick..."

"The grain structure inside the casting is thick, which is normal." From the surface, there are not many problems seen.

It is just that on the surface of the casting, there are some places where irregular holes as big as thumbs, which is the trachoma caused by casting defects.

In the middle position, this defect is more obvious.

After reading it, Xie Kai didn't say anything and followed it into the casting workshop.

In the casting workshop, it was like a stove. Before entering the door, I felt a wave of heat coming towards me. In an instant, sweat soaked the back of my clothes.

Eight huge smelting furnaces are placed on both sides of the entire workshop, and the steel ingots inside the furnace are melting.

In the center of the workshop, a huge sand casting mold that is one person tall is placed like this.

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

When the two of them entered, several people wearing safety helmets were holding drawings and pointing at the surroundings.

Xie Kai looked confused.

He took the safety helmet handed over by Jiang Ming and put it on his head and walked inside.

"If you are ready, prepare to ignite the fire. You must make the entire mold heat evenly and keep the temperature consistent." Minister Chen Hong said after a 50-year-old technician wearing a safety helmet pointed to the drawings to introduce the situation to the people around him.

"What's wrong?" Xie Kai came up, originally planning to figure out the situation, but he didn't hear anything.

What should be added to carbon in the middle mold?

"Are you here?" Chen Hong looked at Xie Kai with a smile on his face, "I heard that your exam was very good."

"I didn't expect that the question would be so simple after not paying attention and putting some effort on my part." Xie Kai was not humble at all. Looking at Chen Mingshan and Zhile on the side, he was thinking in his mind whether Dean Chen would vomit blood when he went to study philosophy.

Chen Mingshan was a little awkward when Xie Kai saw it. He thought there was something wrong with his appearance, but after checking for a long time, he didn't find any problems.

But it's hard to ask.

"What is this for? Isn't it casting? Why are you adding carbon?" Xie Kai asked, pointing to the mold next to him.

This mold is not small.

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

"In the past, the castings were cooled too quickly outside and did not dissipate internally, so the internal grain structure was large... According to our analysis, during the casting process, when the steel contacts the mold, the joints will be quickly cooled..." Chu Guorong explained to Xie Kai.

"But if the heating temperature is too high, it will not damage the sand mold and affect the entire casting?" Xie Kai asked with a frown.

Previously, because the cooling was too fast, the quality of the entire large casting had major defects.

Now it is necessary to reduce the cooling speed by heating outside the mold, which makes the whole process more difficult to control.

Once there is a problem with the process, it will definitely be scrapped.

The molten steel in the surrounding several melting furnaces was almost melting completely.

"For this casting, a team of hundreds of people has conducted dozens of experiments in the past few months, continuously improved the methods and studied the time points of cooperation, so that such a solution was found. The method is very rustic, but it works." Chen Hong said, "Otherwise, you can only use larger forging equipment for forging and then heat treatment..."

"This is hundreds of tons, heat treatment..." Xie Kai felt terrifying when he thought of such heat treatment of large parts.

For heat treatment, it is necessary to heat the entire part to make the metal crystal structure inside the part become fine.

But it is so big that it is too difficult to heat it and keep it warm for a long time.

Once the heating is uneven, the entire product will eventually cause great differences in the metallographic structure of the entire product. If the stress 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 bear tens of thousands of tons of working pressure, but also has to bear the pressure generated by thousands of tons of parts, molds, etc. connected to the main beam.

The internal structure is inconsistent, and the ultimate situation is that the stress is concentrated in parts of the coarse grain structure. These parts have very large grains and are constantly under stress. Under the accumulation of force, it will eventually cause the internal coarse grain structure to detach and cracks, resulting in the final break...

"This process is equivalent to the conditioning and processing. Ordinary castings are produced, cast in the mold to gradually cool the molten steel inside. This cooling process is actually from the outside to the inside. The mold outside comes into contact with the air and emits heat. First, the cooling is completed. Then the temperature of the molten steel inside is transferred and gradually cools down... Therefore, during the casting process, the more outside the position, the finer the grain structure will be..." Chu Guorong continued to explain.

Xie Kai understands these theories.

The problem is that by controlling the temperature around the castings, can we solve the current problems?

"So, this time, the cooling process of the entire casting will be extended?" Xie Kai understood why. "Can this method be useful? The temperature outside and the internal temperature are uncontrollable, especially the temperature inside the casting..."

Because of understanding, you know how difficult it is.

"It's not uncontrollable. According to our multiple experiments and calculations, the temperature outside has a direct relationship with the temperature inside the casting. In order to control this temperature, we have specially established a mathematical model. Once successful, no matter what other large castings are used for, there is no problem!" Chen Mingshan said proudly, "In the future, you will be able to come into contact with this mathematical model when you come to our college."

He thought this model would have a great attraction to Xie Kai.

However, Xie Kai just looked at him and smiled.

"Although the method is soil, there are many things involved, so it took so long to start casting again." As the Minister of Industry, Shen Hong attached great importance to this matter. "Slowing the cooling speed and trying to maintain the temperature consistent with the inner center of the casting as much as possible, so that the grain structure can be refined and the mechanical properties will be better..."

The master, who has presided over the design of nine complete sets of industrial equipment in China, has no intention of underestimating the importance of large presses.

Xie Kai nodded and said nothing.

The entire project is a very big challenge. There is no precedent in China and foreign experience cannot be learned from it. Such a method is absolutely impossible to choose such a way internationally.

What is the result? You can only know until the final casting is formed.

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

Experience is accumulated.

Many things, even if you know the craftsmanship and the details are a little surprised, will have immeasurable results.

"I hope there is no problem this time. Many of our projects are waiting for the large press." Zheng Yucheng sighed and said with a worried look on his face. "According to the previous progress, the main beam has been processed and is ready to be installed."

"This is something that there is no way. I didn't think comprehensively before. I paid too much tuition this time." Minister Shen Hong was also a little distressed.

People with the second level are even more painful.

The scrapped one can be sold for hundreds of thousands of yuan, but they have to pay for the production costs, electricity bills, molds, etc.

"Yes, it is also because of funding issues that many of our production progress 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-ton or 80,000-ton large press construction plan, follow the contract. Besides, won't the Yishen also bear the losses?" Zheng Yucheng blocked Jiang Ming's words directly.

This project was jointly carried out by Yihe, Erhe and dozens of other state-owned units, and built a 45,000-ton die forging machine with a fund of 200 million yuan.

in the country, it is already the largest project with a single equipment.

"The first pile only bears the part, most of it is borne by the second pile. Nowadays, the second pile does not have much business." Chen Hong also spoke.

They hope that 404 can bear part of the funding.

The entire project is too difficult and there is no experience to learn from.

It is a total of concentrated efforts in the country to carry out research and development, and the funding is much higher than the original budget.

"Minister Chen, if this continues, we will not be able to cooperate in the future. No matter how we need it, we will not be able to invest in the big press again." Xie Kai said dissatisfied. Logically, Chen Hong should not help Erzhong and other units speak.

Chen Hongrao looked at Xie Kai with interest, and didn't say anything.

Waiting for Xie Kai to continue talking.

"We invested in building large presses, and each unit undertakes business. In this process, we challenged their existing technical systems and cultivated their internal strength... In the end, the technology is theirs... When we purchase large presses, we give enough costs. They incur extra costs during their own experiments. If we bear it, it will not comply with the principles of the market economy..." Xie Kai said.

The meaning is very clear. Each unit uses the construction funds of 404 to improve its own technical level, and eventually causes losses due to its own reasons in the process. It is impossible for 404 to pay for it.

The 404-yuan fund cannot be used to support the development of the entire system.

Each of them has to bear the improvement of technical level, and 404 is only the purchaser.

"In addition, according to what we know, the units that undertake various core components and systems all have subsidies from the Ministry of Finance, right?" Zheng Yucheng asked.

It’s hard for the whole group to say more.
To be continued...