Engineer Osman is now in front of the projector to explain the structure and how to manufacture the sensor, buzzer and spark plug in the electrical instrument accessories, his explanation is very detailed, as long as people who have studied engineering and manufacturing can understand, but Liu Lang knows, it is one thing to understand, and it is another thing to be able to manufacture.

First of all, there is the problem of materials, these parts are all composed of high-quality steel, and the indicators exceed the highest national index of steel two grades.

But fortunately, because Liu Lang led a group of people to overcome the stainless steel smelting technology, the standard of this steel is very close to the material of most parts, even if the material of some parts is higher, Liu Lang believes that as long as the original smelting furnace is upgraded again, the standard can be reached.

Now the industrial stainless steel smelting furnace is still under construction, at most more than a month later, after these smelting furnaces are put into operation, the country can instantly improve a lot in terms of materials.

Of course, even if high-strength stainless steel is smelted, there are still many problems in terms of materials, such as melting the metal into a liquid and pouring it into the mold during the casting process, which is very difficult.

The first is the design and production of molds, the importance of molds is self-evident, to a certain extent, it is the key to the production of parts, without molds, complex parts are impossible to manufacture.

There is also the treatment of the smelting process, such as the solution of residual stress, exhaust, release agent spray and other defects in the process of cooling and solidification, after all, the car is not an ordinary machinery, the parts are running in a high-temperature and high-friction environment, and there will be fatigue defects if there is a slight flash metal in the casting process, and then it will be a big problem, which is the most important problem to be solved when casting parts.

Of course, the most critical issue is still in the machine tool, without the machine tool is not to talk about anything.

The country's own machine tools can only be manufactured "stupid and coarse" parts, used in smelting and mining can also be, but also have to be "leisurely" use, if you hurry up and dry quickly, then there will be problems, two years ago Liaobei Province to Fucheng issued an annual increase of 20 percent of coal production, when Liu Lang's father Liu Donglai was in the bearing factory is almost no weekend, is because the mining equipment is too weary, high-speed operation, a large number of bearings will be grinded into potholes and then unusable.

Of course, through Liu Lang's contact, the country is now talking with Germany about the introduction of machine tools, as long as it can be successful, this problem can have a lot of progress, but the machine tool itself is only an important condition, and the process is a big problem.

Osman also said, the same part, choose a different direction and wiring cut out, but the life is obviously different, this is a process problem, after all, most of the current machine tools are not numerical control, can not be in a standardized mode to input commands, and electronic control is just more accurate, if the position has to be grasped by the technician

Osman is a very good person, and also gives an example to illustrate the importance of the process, for example, a part should move back and forth in the cylinder bore for tens of millions of times, and its error requirements are extremely high, but no matter how small the error is, there is still an error, even if it is a few points and zeros, it will be infinitely amplified in tens of millions of movements, so a process is required for the surface processing of the cylinder wall, called honing process, which can ensure that the surface of the cylinder bore is wear-resistant and can also attach a layer of oil film to ensure sealing performance.

At this time, the honing process is not mastered by anyone, in the casting process of the machine tool is not good, even if it is bent a little, the movement of the parts thousands of times will accelerate the aging of the cylinder wall.

After talking about the process, Osman said welding, to be honest, there is no shortage of welders in Chinese factories, but their skills are at the level of children in the eyes of the Germans.

Osman cites as an example a common problem called thermal cracking, which occurs at high temperatures when parts are welded.

This type of thermal cracking is characterized by cracking along the proto-austenite grain boundaries. Depending on the material of the metal to be welded (the shape, temperature range, and main causes of thermal cracks are also different, hot cracks are divided into three categories: crystalline cracks, liquefaction cracks, and multilateral cracks.

Crystalline cracks are mainly generated in the welds of carbon steel and low-alloy steel with more impurities (including S, P, C, Si) and single-phase austenitic steel, nickel-based alloys and some aluminum alloys.

The prevention and control measures are to appropriately adjust the metal composition of the welding in terms of metallurgical factors, shorten the range of brittle temperature zone, and control the content of harmful impurities such as sulfur, phosphorus and carbon in the welding process.

Liquefaction crack in the proximal zone is a kind of micro-crack that cracks along the austenite grain boundary, its size is very small, and occurs in the HAZ proximal zone or interlayer, the prevention and control measures of this crack are basically the same as the crystalline crack, and it is very effective to reduce the content of low-melt eutectic elements such as sulfur, phosphorus, silicon, boron and so on, and in terms of process, the line energy can be reduced, and the concavity of the melt pool fusion line can be reduced.

Multilateral crack is caused by the low plasticity at high temperature in the process of forming multilateralization, and its prevention and control measures can add elements such as Mo to the weld to improve the multilateralization intensification energy.

In addition to hot cracks, there are reheat cracks, cold cracks, lamellar tears, etc., which are often problems in the welding process, and how to solve them is also clear.

The various problems in the welding process are too important for the industrial industry, even if those factory directors have listened to each other's "lectures" several times, they are still very serious at this time, and some people take out small notebooks and keep recording.

Osman spoke for more than an hour, and explained the three parts of the projector from the material to the casting, and then to the various problems that will arise clearly, Liu Lang, Xiong Huaizhi and others have gained a lot, but at the same time, they have also more deeply realized the country's shortcomings in this regard.

"In the previous life, it took seven years for the country to finally complete the localization of Volkswagen, and I still think it was a bit long, but now it seems that seven years is really not too long!"

Liu Lang sighed.

After Osman's explanation, everyone stood up and applauded warmly, it can be seen that the other party is not hiding his secrets, but sincerely hopes that the other party can understand, if it is replaced by a domestic company, it is probably a cover-up, of course, the most core technology of the people will not be taken out to show you to you.

"Thomas, Mr. Osman, your explanation is really good, on behalf of Huaxia University, I would like to express my heartfelt thanks to you, thank you!"

Xiong Huaizhi said to several German colleagues.

"Mr. Xiong, China and Germany are now a family, and we want to let you improve your industrial level faster and manufacture parts that meet our standards as soon as possible, so that we can achieve a win-win situation!"

Thomas replied.

"Mr. Thomas, can you give us a copy of the drawings and various related materials of your parts?"

Liu Lang suddenly spoke.

"No problem, we print a lot of these things, and we won't hide them in this regard!"

As soon as Thomas waved his hand, two people left immediately, and after a few minutes, he came back with two stacks of drawings and materials, and the two students behind Xiong Huaizhi immediately picked them up.

"Good fellow, it's a lot of weight!"

One person almost didn't catch it.