Licheng is a mining city. Guangrong City is a tourist city. Huixiang is an industrial city. Tengju City is a cultural city.
Duan Zhu, Sun Shiji, and Wu Tian are freshly graduated students majoring in mechanics. They heard that a new city, Shengshi City, is to be built between Yuzicheng and Hehuijincheng. Duan Zhu, Sun Shiji, and Wu Tian plan to go here to find jobs.
The city is very new, and its modular construction requires a large number of mechanical parts.
General types of engineering machinery include: excavating machinery, shovel transport machinery, engineering hoisting machinery, industrial vehicles, compaction machinery, road machinery, piling machinery, concrete machinery, steel bar and prestressed machinery, decoration machinery, rock drilling machinery, pneumatic machinery Tools, railway line machinery, excavation machinery. Now there are more machines related to prefabricated buildings.
During the construction process of Shengshi City, a large amount of on-site work in traditional construction methods was transferred to the factory. The building components and accessories, including floor slabs, wall panels, stairs, balconies, etc., were processed and manufactured in the factory and transported to the construction site. A building assembled and installed on site with reliable connections. The prefabricated construction method has fast construction speed, meets the requirements of green buildings, and is energy-saving and environmentally friendly. The prefabricated components of prefabricated concrete buildings can be divided into four types: main structural components, peripheral protection system components, interior components, and equipment and pipeline components.
Duan Zhu learned that prefabricated buildings require screws, bolts, nuts, etc. Mechanical professionals are needed.
Some time ago, they spent time studying the manufacturing methods of these parts. When applying for other companies, I guess you still have to research these things.
The process and process of screw production are: disc unit-annealing-pickling-drawing-forming-rolling-heat treatment-electroplating-packaging.
1. Pan unit: Purchase the original wire rod from the manufacturer. A unit mainly includes the following parameters: brand, product name, specification, material, furnace number or batch number, quantity/weight. The main chemical components in steel are: C, M
, P, S, Si, Cu, Al, where the lower the content of Al and Cu, the better. 2. Annealing: Heat the wire to an appropriate temperature, maintain it for a certain period of time, and then slowly cool it to adjust the crystal structure, reduce the hardness, and improve the processability of the wire at room temperature. 3. Pickling: Remove the oxide film on the surface of the wire and form a phosphate film on the metal surface to reduce scratches on the tool and mold during wire drawing and cold piercing or forming. 4. Wire drawing: Cold draw the disc element to the required wire diameter. Practically, some products can be divided into two stages: rough extraction and fine extraction. 5. Forming: The wire is cold forged or hot forged to achieve the shape, length or thickness of the semi-finished product. 6. Thread rolling and tapping: rolling or tapping the formed semi-finished product to achieve the required threads. Practically speaking, bolts and screws are called thread rolling, tooth bars are called rolling threads, and nuts are called tapping threads.
The general nut manufacturing process has the following steps: Steel stamping and forming. Tapping means processing threads. Heat treatment, generally higher-level nuts require heat treatment, while lower-level nuts do not require heat treatment. After the above production process, the nut has been basically formed. The last step of the process is surface treatment.
On their way to Shengshi City, several people wanted to see the scenery nearby. On the way back to the main road in the evening, I saw something unusual about the lights in front of me.
Duan Zhu said: "Is there something wrong with the car lights? Why do they sometimes not illuminate the front?"
Sun Shiji said: "Yes. Sometimes the light from the car lights cannot be seen."
Wu Tian said: "There may be something wrong with the car. Why is it not driving smoothly? It was quite smooth."
Sun Shiji said: "Really, you shouldn't have come so far. Get to Shengshi City as soon as possible."
Duan Zhu said: "Why did you stop?"
Sun Shiji said: "I didn't stop. Maybe the car broke down."
Wu Tian said: "It's such a desolate place. Come down quickly and see if it can be repaired." He got down and opened the front hood of the car.
Duan Zhu said: "What's the problem?"
Restart again. Looking at a strange scene in front of me. I couldn't help but get goosebumps all over my body and my hair stood on end.
The light beam of the car light seemed to be bent by something, shining downward to the ground, and then bent to one side. Facing the nearby trees.
Duan Zhu said: "What kind of light is this? Is it an aurora?"
Aurora is a colorful plasma phenomenon caused by the flow of charged particles from the sun entering the earth's magnetic field. It is a brilliant and beautiful glow that appears at night in the high altitudes near the earth's north and south poles. The Earth's auroras are produced by high-energy charged particle flows from the Earth's magnetosphere or the Sun that excite or ionize molecules or atoms in the upper atmosphere.
In the South Pole they are called the Aurora Australis and in the North Pole they are called the Aurora Borealis. What we have here is neither the South Pole nor the North Pole.
Where there is a flow of charged particles, it's the light from the headlights. Could it be that car lights can also emit streams of charged particles?
Most auroras appear between 90 and 130 kilometers above the Earth. It's too short here.
The magnetic field lines of the Earth's magnetosphere carry the energy of the solar wind into the Earth's interior, thereby driving the formation of the Earth's magnetic field. In this closed loop of magnetospheric magnetic field lines, in addition to the conductor inside the earth, there is also the ionosphere of the atmosphere, a weak conductor. When the solar wind is strong, the energy of the magnetic field lines encounters the magnetic inductance inside the earth, and a lot of energy cannot be consumed, so auroras are formed in the ionosphere.
Wu Tian said: "What is going on? It seems that the whole space is distorted."
Duan Zhu said: "Why are other things not distorted, only this light?"
"Yes, the car is fine, and so are we." They looked at each other.
Wu Tian said: "It seems to only attract special substances. For example, light. It's like a magnet only attracts ferromagnetic substances."
Duan Zhu said: "Let's see what's next to here?"
Wu Tian said: "Don't look at it, it's too scary. I feel like I need a tow truck to get out of this place."
Sun Shiji said: "I'll make a call right now." But there was also a problem with the mobile phone signal.
They had no choice but to walk cautiously toward where the light was bending. Then you have to walk a long way to the main road and catch a ride.
A distance where light bends. I saw a stone behind the tree.
Wu Tian said: "What is this? A meteorite?"
Duan Zhu said: "Let's take a look."
Sun Shiji said: "I don't know, don't get close, meteorites also have radiation."
Wu Tian said: "The main minerals in meteorites include carbides, sulfides, oxides, silicates, and phosphates. Is it related to these substances?" Meteorites are cosmic meteors that have deviated from their original orbits outside the earth. Or unburned stone, iron, or a mixture of stone and iron whose fragments are scattered on the surface of the planet.
Sun Shiji said: "I have never heard that these will affect the change of light."
Duan Zhu said: "Take this thing with you first. Go back and take a look."
Wu Tian said: "Then you carry it. This thing is relatively heavy."
Duan Zhu said: "Let's punch to make sure."
Finally they took turns carrying the stone to the main road. Take a ride to Shengshi City.
