Engineer Osman is now in front of the projector explaining the structure and how to manufacture the three components of the electrical instrument system: sensor, buzzer and spark plug. His explanation is very detailed, and anyone who has studied engineering manufacturing can understand it.
He understood it, but Liu Lang knew that it was one thing to understand it, but it was another thing to be able to produce it.
The first is the issue of materials. These parts are all made of high-quality steel, and each index exceeds the country's highest index steel by two levels.
But fortunately, because Liu Lang led a group of people to conquer the stainless steel smelting technology, the standard of this steel is already very close to the material of most parts. Even if some parts are made of higher materials, Liu Lang believes that as long as
Once the technology is upgraded on the original smelting furnace, it can reach the standard.
Industrial stainless steel smelting furnaces are still under construction. In more than a month at most, when these smelting furnaces are put into operation, the country will be able to improve a lot in terms of materials in an instant.
Of course, even if high-strength stainless steel is smelted, there are still many problems in terms of materials. For example, during the casting process, the metal is melted into liquid and poured into the mold, which is very difficult.
The first is the design and production of molds. The importance of molds is self-evident. To some extent, they are the key to the production of parts. Without molds, complex parts cannot be manufactured.
There are also processing issues during the smelting process, such as solving residual stress during the cooling and solidification process, exhaust, release agent spraying and other things that cause defects. After all, cars are not ordinary machinery, and parts operate at a high temperature.
In a high-friction environment, a slight loss of metal during the casting process will cause fatigue defects, which will become a big problem. This is the most important problem that needs to be solved when casting parts.
Of course, the most critical issue is the machine tool. Without the machine tool, nothing can be discussed.
The country's own machine tools can only produce "stupid, big and crude" parts. They can be used in smelting and mining, but they have to be used "slowly". If the work is done quickly, problems will arise. Two years ago, Liaoning
Northern Province ordered Fucheng to increase coal production by 20% every year. At that time, the bearing factory where Liu Lang's father Liu Donglai worked almost had no weekends because the mining equipment was too worn out. Under high-speed operation, a large amount of coal was produced in a few days.
The bearing will be worn into pits and become unusable.
Of course, through Liu Lang's contact, the country is now discussing the issue of introducing machine tools with Germany. As long as it can succeed, this issue can make considerable progress, but the machine tool itself is only an important condition, and the process is also an important factor.
Big problem.
Osman also said that the same part is cut out in different directions and wiring, but the lifespan is obviously different. This is considered a process problem. After all, most of the current machine tools are not CNC and cannot input commands in a standardized mode, and electronic control
It's just more precise. If you want to move it, it's up to the technician to control it.
Osman is a very good person. He also gave an example to illustrate the importance of craftsmanship. For example, a part needs to move back and forth tens of millions of times in the cylinder bore. The error requirements are extremely high, but no matter how small the error is, there is still an error.
Even the error of a few zeros and tenths will be infinitely amplified in tens of millions of movements. Therefore, processing the surface of the cylinder wall requires a process called the honing process, which can ensure that the surface of the cylinder bore is durable.
It can also adhere to a layer of oil film to ensure sealing performance.
At this time, not everyone can master the honing process. During the casting process, the machine tool cannot move well, even if it bends just a little, the millions of movements of the parts will accelerate the aging of the cylinder wall.
After talking about technology, Osman then talked about welding. To be honest, there is no shortage of welders in Chinese factories, but in the eyes of Germans, their skills are at the level of children.
Osman gave an example of a common problem called hot cracking that occurs when parts are welded at high temperatures.
The characteristic of this kind of hot crack is cracking along the original austenite grain boundary. Depending on the material of the welded metal (the shape of the hot crack, the temperature range and the main reasons are also different, so the hot crack is divided into crystal cracks and liquefaction cracks
and multilateral cracks.
Crystallization cracks mainly occur in welds of carbon steel and low alloy steel containing more impurities (including S, P, C, and Si) and in single-phase austenitic steel, nickel-based alloys and some aluminum alloy welds.
, this kind of crack occurs during the welding crystallization process, near the solidus line, due to the shrinkage of the solidified metal, the residual liquid metal is insufficient and cannot be filled in time, and intergranular cracking occurs under the action of stress.
The prevention and control measures are to appropriately adjust the metal composition of the weld metal in terms of metallurgical factors, shorten the range of the brittle temperature zone, and control the content of harmful impurities such as sulfur, phosphorus, and carbon in the weld metal; in terms of technology, preheating before welding can be used to control the line energy.
Prevent and treat it by reducing joint constraints and other aspects.
Liquification crack in the near-seam area is a microcrack that cracks along the austenite grain boundary. Its size is very small and occurs in the HAZ near-seam area or between layers. The prevention and control measures for this type of crack are basically the same as those for crystallization cracks.
, it is very effective to reduce the content of low-melting eutectic elements such as sulfur, phosphorus, silicon, and boron as much as possible. In terms of technology, it can reduce the line energy and reduce the concavity of the molten pool fusion line.
Polygonal cracks are caused by low plasticity at high temperatures during the formation of polygonal cracks. The prevention and control measures can be to add elements such as Mo, W, etc. to the weld that increase the polygonal excitation energy.
In addition to hot cracks, there are also reheat cracks, cold cracks, lamellar tears, etc. These are all problems that often occur during the welding process. Osman also explained clearly how to solve them.
The various problems that arise in the welding process are so important to the industrial industry. Even though the factory directors listened to each other's "lectures" several times, they were still very serious at this time. Some people took out small notebooks and kept recording.
Osman talked for nearly an hour, explaining clearly the three parts of the projector from materials to casting to various problems that would arise. Liu Lang, Xiong Huaizhi and others gained a lot, but at the same time they also learned a lot.
We have a deeper understanding of the country’s shortcomings in this regard.
"In the previous life, it took the country seven years to finally complete the localization of Volkswagen. I thought it took a long time, but now it seems that seven years is really not too long!"
Liu Lang sighed.
After Osman's explanation, everyone stood up and applauded enthusiastically. It can be seen that the other party did not hide anything, and he sincerely hoped that the other party could understand. If it were a domestic company, it would probably be secretive. Of course
, the most core technology will not be shown to you.
"Thomas, Mr. Osman, your explanation is really great. On behalf of Huaxia University, I would like to express my sincere gratitude to you. Thank you!"
Xiong Huaizhi said to several German colleagues.
"Mr. Xiong, China and Germany are now one family. We are doing this to help you improve your industrial level faster and manufacture parts that meet our standards as soon as possible, so that both of us can achieve a win-win situation!"
"
Thomas replied.
"Mr. Thomas, can you give us a copy of the drawings of your parts and various related materials?"
Liu Lang suddenly spoke.
"No problem, we print a lot of these things, and we won't hide anything in this regard!"
Thomas waved his hand, and two people left immediately. A few minutes later, they came back with two stacks of drawings and information. The two students behind Xiong Huaizhi immediately took them over.