Chapter 278 Help Mr. Xiang to make things right
The next day, the Seventeenth Machinery Department and its affiliated third rolling mill and Beijing Steel Plant received a notice from the Ministry of Chemical Industry, asking them to attend the meeting together that afternoon. Demonstration meeting of the Ministry of Chemical Industry on officially promoting the construction of industrialized urea plants.
The reason why we invited them is very simple. All urea steels are provided by the 17th Machinery Department, and as the No. 3 Rolling Mill and Beijing Steel Plant are the pioneers of urea steel, this demonstration meeting is also very necessary. Invite them to participate. After all, they are more familiar with the properties of materials.
Gao Zhendong received the notice and put it aside for the time being. He is now busy explaining the new thermocouple to Liang Fafa and Liu Rongguo.
The new thermocouple selected by Gao Zhendong is type B thermocouple. The outstanding features of this thermocouple are wide temperature range, long life, high upper limit, and among the graduation numbers of all thermocouples, Type B has the highest accuracy and best stability and does not require temperature compensation wires.
Of course, this thing is not without its shortcomings. It has a small thermoelectric potential rate, low sensitivity, poor mechanical strength at high temperatures, and is afraid of contamination. It is not suitable for reducing atmospheres or atmospheres containing metal or non-metal vapors. Therefore, the protective tube of this thing It's quite special, but it just so happens that Gao Zhendong has the technology to solve this problem.
Gao Zhendong didn’t make this thing at first. One reason was that the technology he had at that time could not support the production of this thing. The second reason was very simple and direct: expensive!
This thing is not generally expensive. Compared with the K-type thermocouple that can work at 1300℃ and does not use precious metals at all, although the B-type thermocouple can work at 1600℃ and 1800℃ for short-term operation, it is large. In some application environments this is not useful.
On the contrary, its material determines that it cannot be widely used. Its electrode uses platinum rhodium 30-platinum rhodium 6, that is, the positive electrode (BP) is 70% platinum and 30% rhodium. , the negative electrode (BN) is 94% platinum and 6% rhodium, so it is also called a double platinum-rhodium thermocouple.
The price of this thing is too high compared to the K-type material.
But in high temperature environments, this thing is still useful.
Gao Zhendong told Liang Fafa and Liu Rongguo the electrode ratio of the B-type thermocouple. Both of them were secretly dumbfounded. This thing is too expensive. No wonder Director Gao was reluctant to do it at first. It was really because Difficult to popularize.
When they heard about the weaknesses of type B thermocouples, the two were in trouble.
Liang Fafa first proposed: "Director Gao, since this thing is not suitable for reducing atmospheres or atmospheres containing metal or non-metal vapors, what should be used as a protective tube?"
Gao Zhendong smiled and said: "Then we will protect it with natural materials and earthly treasures that are neither gold, jade, wood, nor iron."
Gao Zhendong casually made a quick wit. This adjective commonly used in immortality novels from his previous life immediately stunned Liang and Liu. They really couldn't understand it.
Looking at the confused looks on the two people's faces, Gao Zhendong smiled: "Just kidding, we use corundum."
The melting point of corundum is as high as over 2000°C, which just covers B The operating temperature range of type B thermocouples, and no metal or non-metallic vapor will be generated at this temperature, just meets the requirements of type B thermocouples.
But after using this thing, the price is even higher.
“Corundum?”
The two of them were familiar with steel, but they were far less familiar with other things than Gao Zhendong, and they didn't even know what they were.
Gao Zhendong smiled and said: "Yes, corundum is aluminum oxide (Al2O3)."
The two of them thought about it and realized that this thing is really good. It just meets the requirements of type B thermocouples. The melting point It has high hardness, but it is difficult to process. After all, this thing itself is expensive.
Apart from processing issues, what can be called "corundum" is crystal-level alumina.
Liu Rongguo asked: "How do we get corundum crystals that meet the requirements?"
Gao Zhendong pointed to the direction of the single crystal furnace laboratory: "You have forgotten, I have a single crystal furnace, just pull it a little."
The two of them realized that although the corundum crystal is not large in size , but it is just right to meet the needs of type B thermocouples.
Both of them admired Gao Zhendong in their hearts for doing things so closely that the results of the previous project could be applied to the next project.
Actually, this is really over-imagining. When Gao Zhendong was studying the single crystal furnace, he didn’t think about the problem of type B thermocouples at all. After all, making this thing was a temporary idea, and it was a slap in the face to the "study" comrade. result.
Then Gao Zhendong told me one more thing: "Please pay attention, the diameter of the even wire is 0.5mm, and the allowable deviation is -0.015mm."
Although this requirement is more difficult for Liang Fafa and Liu Rongguo, it is not difficult for the third rolling mill, especially when it is only producing in small batches. Liang Fafa and Liu Rongguo got a complete set of designs from Gao Zhendong and excitedly prepared to make B-type thermocouples. Although the report of the technical transformation factory has not yet been submitted to Gao Zhendong for review, it is better to get things done first. That's right.
When they left, they also left something behind: test reports of two tungsten copper materials.
The test results show that the tungsten copper material fully meets Gao Zhendong’s design intention.
Considering that there were a lot of things submitted to the 17th Machinery Department recently, in order for the department to digest them first, Gao Zhendong temporarily received the inspection reports of the two tungsten copper materials in the safe.
Gao Zhendong also put together a batch of throat liners that had been made. When he was free in a few days, he would send them to the Research Institute and ask them to test their high-temperature performance.
——
That afternoon, when Gao Zhendong rushed to the meeting room of the Chemical Department, he found that several acquaintances were already inside.
The leader of the 17th Machinery Department personally attended the meeting, not because he was too idle and attended every meeting. But the food issue has always been a top priority, and as the ministry responsible for material production, it was only natural for him to be present in person. It was difficult for others to make decisions on many things without him.
It was a coincidence that the other person was Zheng Liangshu, the leader’s former secretary, who has now been transferred to the Capital Steel Plant. As the person in charge of the AOD workshop, it was normal for him to be present. It has nothing to do with production. Production matters can only be decided by the 17th Machinery Department. He is here with the same status as Gao Zhendong, representing another research unit of urea steel.
Several people said hello and sat together. As researchers of urea steel, Gao Zhendong and Zheng Liangshu were honored to sit in the first row, which was just right.
Other participants include relevant experts from the Ministry of Chemical Industry, people from Nongkou, and people from the Ministry of Foreign Commerce, because this meeting involves the issue of how much urea steel they can sell. Once it is decided to promote it, it must first meet domestic demand.
The meeting actually focused on two points: one was to ask the general manager whether the accelerated aging method they used could reliably evaluate the service life of the production line in the actual production environment; the other was that once promoted, urea steel Whether the output can meet the demand.
In fact, the first problem is the most troublesome. The life evaluation of the urea production line is very troublesome.
The main concern of the urea production line is the corrosion life. As it happens, there is no good method for the corrosion life in the rapid evaluation of equipment accelerated testing.
In Gao Zhendong's previous life, even for things like temperature, stress, and vibration, there were various accelerated test methods in relevant standards. However, there were related test methods for corrosion in chemical testing, but the accelerated corrosion test method was used for production equipment. , but it is relatively lacking.
Basically all corrosion prediction methods are based on a large amount of historical data and real-time monitoring, but now in the case of urea steel, this condition is obviously not met.
Even in the accelerated testing and evaluation of military equipment, the issue of corrosion life is mentioned in a general way: "The relevant theory is weak and can be estimated using similar analogies."
The similar analogy method can only be used when there is corrosion monitoring information on similar or similar products to estimate the corrosion life of the product
But the problem is that this is a new material and there is no historical data to use. Similar The analogy method has lost its usefulness, and it is difficult for monitoring methods these days to provide corrosion monitoring information.
Therefore, the corrosive soil method proposed by President Xiang and others to accelerate the test results did not completely dispel the doubts of the participants. Everyone was not sure how long this thing could last in a production environment.
As for this question, there is no doubt that apart from Mr. Xiang and the others, the most authoritative person, or the most suitable person to answer this question, is definitely Gao Zhendong.
Although Zheng Liangshu represents another research party, his knowledge structure is obviously not suitable to answer this question.
The leader of the Chemical Industry Department personally ordered: "Director Gao, as a researcher of urea steel and an expert in materials, we would like to ask you to evaluate whether the accelerated corrosion aging method used by Xianggong and others is appropriate. ?”
Seeing everyone turn to look at him, Gao Zhendong was thinking about how he could help Mr. Xiang and the others rationalize this matter.
Gao Zhendong fully believes in the corrosion resistance of this material and its usability in the urea industrial production line. His confidence has nothing to do with Xiang and others, but the source of the material.
In the paper on the source of materials, it is very clear that by the time the paper was published, its working time was far more than one year, and everything was normal within the design life span.
So what Gao Zhendong has to solve is how to make the test results of Mr. Xiang and his colleagues reasonable.
But fortunately, as an automation major, he happens to know a reasonable method. This is what he learned in his previous life. The current automation major will not teach that method because it has not yet been taught this way. developed.
Even Gao Zhendong was taught a small course by his tutor, and none of his classmates had ever studied it, because it was not actually a course in the automation major.
However, the only thing that made Gao Zhendong unhappy was that this method involved partial differential equations, and he had to explain the principle clearly to others. Then during the distance process, he would inevitably have to solve two partial differential equations.
This method is the gray system theory model, a very abstract cybernetics method. Even in Gao Zhendong's previous life, it was considered a new method in the field of cybernetics.
(End of this chapter)