my scientific age

Chapter 222 Suffocation!

Back at school, Yu Hua kept picking up the armored steel samples and left again, still avoiding the organization's protection force. After a lot of twists and turns, he finally delivered the armored steel samples to Rabe before three o'clock in the afternoon.

Then, Yu Hua got the phone number of Rabe's residence and agreed to call at [-] am three days later to get the final result.

After everything was done, what Yu Hua had to do next was to wait.

In the evening, West Courtyard, Room 28.

"Xiaohua, since you are a recommended student and have already reported to the school, the school has arranged for you to start the formal class tomorrow. Are you sure about the general education elective course?" Wu Xiaoyuan, his wife, was clearing the dishes. Just after dinner, Hua Luogeng was sitting on the sofa. , drinking a cup of chrysanthemum tea, said to Yu Hua.

As a recommended student, Yu Hua, who has completed the registration procedure for the school, has no reason to be idle. Tomorrow Yu Hua will start a knowledge-seeking journey belonging to a student of National Tsing Hua University.

"The students are going to apply for Professor Zhao Zhongyao's nuclear physics and Professor Zhuang Qianding's mechanical engineering." Yu Hua nodded and gave his goal.

Hua Luogeng asked curiously, "Are you still interested in nuclear physics and mechanical engineering?"

"Yes, students like physics since childhood. Professor Zhao Zhongyao's nuclear physics is very interesting, and Professor Zhuang Qianding's mechanical engineering allows me to systematically study mechanical engineering and consolidate the foundation." Yu Hua replied.

"I don't interfere with your choice, but remember that you can't chew too much. Professor Zhao and Professor Zhuang are very strict. I'll report it to you tomorrow."

Hua Luogeng nodded and wrote down the general education elective given by Yu Hua, and then instructed: "We usually take classes when we should be in class, don't violate school rules, and respect teachers and elders, but if someone bullies you, don't be afraid, academic matters. , everything has me."

"Students take note."

Yu Hua understood Hua Luogeng's good intentions, wrote it down carefully, and then said, "Master, the students have improved their academic level recently, and they have more ideas about the theory of asymmetric cryptography. The students want to do research in this area."

One month has passed, and his mathematical level and knowledge reserve have improved a lot. Yu Hua has many ideas and understandings of asymmetric cryptography, and it is time to engage in academic research.

"Yes, I support you, but the research must be carried out, and the study must not be left behind." Hua Luogeng heard the words without hesitation, and decided to support Yu Hua's idea, and asked again.

"Students understand." Yu Hua nodded, not the slightest impatience with Hua Luogeng's repeated instructions. This was Master's concern for him.

The things that should be discussed were basically finished. Before it was dark, Yu Hua proposed to his master and his mother the idea of ​​moving to the student dormitory. It is not good to always live in Hua Luogeng’s house. Before, it was because there was no place to live, but now there is a dormitory. , of course to move away.

Hearing Yu Hua's decision, Hua Luogeng nodded in support, and like an elder, let Yu Hua have a good relationship with his classmates. Although his wife Wu Xiaoyuan was a little reluctant, she still chose to support Yu Hua.

After ten minutes.

The door of the house opened slowly.

Yu Hua dragged a cowhide suitcase with personal clothes and books, walked out of the house, and stood at the door, followed by Hua Luogeng and Wu Xiaoyuan.

The whole person stood at the door, turned around, and bowed to the two of them: "Master, Master, the students have gone to the dormitory."

Hua Luogeng nodded and smiled without saying a word.

"Xiaohua, pay attention to safety, come back if you have anything, this is your home forever." Wu Xiaoyuan smiled, looking at Yu Hua with kind and gratifying eyes, just like looking at a younger generation who is about to spread his wings.

"Yes." Yu Hua was moved when he heard the words of his wife, and nodded earnestly. Without further delay, he bid farewell to the two of them and turned to head towards the Tsinghua student dormitory.

"This child, I'm not as good as him, and my future achievements are limitless." Hua Luogeng said softly, looking at Yu Hua's retreating back, with hope in his eyes.

……

Peking Banyan Tree Hutong, Siemens Office, [-]rd Floor, Temporary Laboratory.

Here, an unknown material detection experiment is about to be carried out.

Two technicians belonging to Siemens in white lab coats are busy, one middle-aged, one young, and the young experimenter is debugging the Brinell hardness tester placed on the test bench, and there is a metal material tensile test next to it. instrument and other test equipment.

The entire laboratory was set up temporarily. Since the armored steel samples arrived yesterday, in order to keep it confidential and detect it as soon as possible, Rabe directly used the authority of the person in charge and spent nearly a thousand oceans of company funds to build this temporary experiment in the Siemens office. The technical staff are company employees.

Although the cost is expensive, it is nothing compared to Y-type armor steel.

The current mainstream method for testing the hardness of metal materials is the Brinell hardness test. The surface indentation diameter of the sample material was finally calculated to calculate the hardness value.

The Brinell hardness unit is HBW, generally written as HB.

The metal material tensile tester, commonly known as the universal material tester, can be used to test the mechanical properties of the material such as yield strength and tensile strength.

The material testing experiment is about to start. Rabe is standing outside the laboratory, staring at the two experimenters who are making final preparations through the window glass.

The final result of this test experiment is crucial.

In the laboratory, the two experimenters, Hans and Marcus, completed the final equipment debugging. Then, Marcus, the leader, said to Hans: "Hans, start the experiment."

Hans nodded, opened the box where the experimental samples were stored, took out the steel plate samples with silver-gray metallic luster throughout, and placed them on the base stage of the Brinell hardness tester, facing the 10mm diameter cemented carbide circle perpendicular to the top. ball, to be fixed.

Having done this, Hans began to turn the control handwheel of the tester, the stage carrying the Y-shaped armored steel sample was raised, contacted with the 10 mm alloy ball, and then the load was applied manually.

The pressure load of the alloy ball continued to increase, and the unit value reached 19600 Newtons. However, the armored steel sample seemed to be fine, and the contact surface between the ball and the steel plate was only a small area of ​​depression, which could not meet the measurement standard.

This steel plate is so strong!
Seeing this situation, Marcus and Hans looked at each other and found the surprise in each other's eyes that the steel plate did not change under such a pressure load.

The unit load of 19600 Newtons is a full 2000 kilograms of force, which is a painful upper limit for most carbon and alloy steels.

What is the condition of this steel plate, why can it withstand such high pressure without deformation and indentation?

"The pressure load has been increased to 2500 kgf." Marcus looked at the armored steel sample on the stage, and said to Hans with a strong interest in his heart.

Hans nodded and continued to increase the load pressure, reaching 2500 kg force, reaching a pressure value of 2.45 Newtons. As the load pressure increased by a level, the Y-shaped armor steel on the stage finally could not withstand such terrifying pressure, the contact surface Sag, 10mm metal spheres pressed into the interior of the armored steel.

"Keep 15S." Marcus saw this, his face was a little excited. Although he was not a technical expert in the metallurgical industry, he also understood that the steel plate in front of him was extraordinary.

Hold for a certain period of time and then release the applied force, which is the standard procedure for strength testing.

After 15 seconds, Hans, who was in charge of the actual operation, disconnected the load output and controlled the lowering of the stage. The Y-shaped armored steel sample was out of contact with the metal ball indenter, and a spherical metal indentation as big as a grain of rice came into view.

Hans immediately used a micrometer to measure the diameter of the spherical indentation, and when he got an accurate reading, he was stunned.

"What's the diameter reading?" Marcus asked quickly, with a hint of urgency in his words.

"3.98mm, boss." Hans's tone trembled.

Hearing this answer, Marcus was stunned for a moment, only to feel a little dazed in his head: "What, 3.98 mm?! God, that is to say, the actual hardness of this steel plate has reached about 490HB, and measured again, and measured 2 points in a row. , In addition, the pressure load is increased to 3000 kg force, and three points are still tested."

The diameter of the spherical indentation is 3.98 mm, which means that the entire spherical indentation surface area reaches about 50 mm, and the Brinell hardness value is 2.45 N pressure divided by the spherical indentation surface area, and the final value is 490HB.

What is the concept of 490HB?
In 1927, Marcus had the honor to visit the Krupp company, the arms king next door, and witnessed the KC armored steel produced by Krupp for the army. The hardness of the armored steel barely exceeded the 300HB mark.

The hardness value cannot be the core index of steel, but it is an important parameter to measure the performance of steel.

The Brinell hardness of this steel plate sample, which does not look brittle at all, is as high as 490HB, which Marcus really cannot imagine.

"Yes!" Hans, a young technician who clearly understood the meaning of the value of 490BH, nodded again and again, put the armor steel sample back on the measuring machine again, and measured again.

The standard measurement process of hardness of metal materials is to obtain 3 spherical indentations and obtain the average value of the three, which is the most scientific.

Of course, neither Marcus nor Hans are serious material scientists or metallurgical experts. Marcus is a senior electrical engineer from Siemens in China, and Hans is an assistant electrical engineer. level and metallurgical foundation, not up to the level of a material science technologist.

However, it is no problem to do a material performance test.

Soon, Hans measured two spherical indentations under a load of 2500 kg, with diameters of 3.99 mm and 3.98 mm respectively. The average value of the first spherical indentation was 3.983 mm, and the Brinell was finally obtained. The hardness value is 490HB.

Afterwards, Hans successively conducted hardness tests under a load of 3000 kilograms. The diameters of the three spherical indentations were expanded to 4.77 mm, 4.78 mm, and 4.77 mm, respectively. The spherical indentation surface area was 60 mm, and the Brinell hardness remained at 490HB.

Two pressure loads, a total of six test points, all test data are recorded.

"God, what is going on with this steel plate..."

As an electrical engineer, Marcus looked at the experimental data, going crazy. His eyes turned to look at the ordinary-looking steel plate on the stage. He was completely shocked by this steel plate.

Who made this plate?

Why can it have such a high hardness?

No one answered the question in Marcus' mind.

Hans asked: "Boss, are we going to the next round of testing now, or do we give the data to Mr. Rabe first?"

"Test first, use a metal material tensile tester to test its yield strength and tensile strength. I have a feeling in my heart that this steel plate contains great secrets..." Marcus heard the sound and came back to his senses. He took a deep breath to keep calm and said straight.

The material performance test continued. The Y-shaped armor steel sample with six spherical indentations on the surface was transferred to the tensile tester. The young Hans was familiar with the road, as if he had returned to the scene when he was studying at the Zurich Institute of Technology, rigorous and careful, Proficiently control the pull tester.

This is an inch mechanical tensile tester with a maximum load force of 150 kN. It is the equipment with the highest test strength on the market. After the two ends of the steel plate are fixed and locked, everything is ready. Marcus gave the order to start the test.

Yield strength is the yield limit of the metal material when the yield phenomenon occurs. For the metal material without obvious yield phenomenon, the stress value that produces 0.2% residual deformation is specified as the yield limit.

The external force greater than the yield limit will cause the metal material to permanently fail and deform, and cannot be recovered.

If the yield limit of carbon steel is 200MPa, if it exceeds this limit, it will break itself and be permanently deformed.

Hans, who was instructed, began to operate and continued to raise the load.

The Y-shaped armor steel in the instrument is immediately pulled by two forces from different directions. The martensite of the internal metallographic structure easily resists the two outward pulling forces. The grain structure is extremely stable, and the external performance is...

Not moving.

10 kN.

20 kN.

50 kN.

The pressure load continued to increase. Marcus looked at the terrifying value on the tensile tester, his eyelids jumped wildly, and his heart became more and more shocked. This steel plate not only has extremely high hardness, but also has a very high yield strength.

How can this be?

The pressure load has been increased to 100 kN, however, the steel plate in the tester still has no change. If the tensile tester is not making a working sound symbolizing mechanical force, it seems that the test has not been carried out at all.

There was an invisible and dignified breath in the air. Obviously, the Y-shaped armor steel sample standing on the tester brought unprecedented pressure to Marcus and Hans.

The value of the tester increased steadily. After a while, when the pressure load increased to an unprecedented terrifying height, the grains inside the Y-shaped armor steel sample finally broke, the internal stress reached the limit, and the material was obviously deformed.

Seeing this scene, Marcus immediately stopped Hans. His face was unprecedentedly serious, and he recorded the tension parameters at the fastest speed. According to the detailed calculation, he obtained the yield strength value and the tensile strength value respectively.

Yield strength value: 580Mpa,

Tensile strength value: 862Mpa.

Looking at the two results, Marcus almost suffocated, his right hand trembled slightly, and his heart was beating wildly. He had no idea that this steel plate that Mr. Rabe obtained from nowhere would have such terrifying performance parameters.

too exaggerated.

so horrible.

"How is this steel plate smelted? If it was developed by the British and used as a protective material for tanks or warships, it would be a nightmare for our country..." Marcus stabilized his body and stared at the yield strength. The numerical value and tensile strength value immediately realized the huge application value of this steel plate in the military field.

The same is true for the young Hans, who graduated from the Institute of Technology in Zurich and clearly understands what this set of material performance data means.

In the temporary laboratory, there is a breath of suffocation and despair.

"Hans, you send this test report to Mr. Rabe, and then, in my name, ask him to get the formula for this steel plate for the motherland." Marcus said solemnly.

"Yes!"

Hans nodded immediately.

(End of this chapter)