"Xiaoyun, tell me, how should this problem be solved?" In the machining workshop of Rongcheng Xinkaixing Ball Screw Factory, Wang Qingfeng stared at Yun Fei with a gloomy face.

"How do you arrange this production process? Did those Soviet engineers just eat and not work? "Yunfei used a micrometer to take several points on the ball screw produced on site, and the size of each point measured had very slight changes.

The ball screw measured by Yun Fei is not very long, only more than 300 millimeters and less than 400 millimeters. Such a short ball screw has a knife phenomenon in the grinding process, and such a short screw is actually a whole trace larger than the two ends in the middle! If the two or three meters long ball screw, the center hole at both ends of the grinding of the arc-shaped spiral groove on the ball screw, on the almost rigid screw, this knife phenomenon will be more obvious, then I don't know how much larger the middle of the tunnel will be than the two ends.

In this way, these ball screws simply cannot achieve the accuracy of the design, and the CNC machine tool using such a ball screw can still ensure the machining accuracy?

"The No. 45 steel we use is quenched and tempered after forging, and the lathe is used to rough the threaded groove, and then the surface is quenched at high frequency, and then grinded." Although Wang Qingfeng, the general manager of the ball screw factory, does not know much about the ball screw, it is impossible to know nothing about the production process.

In particular, Wang Qingfeng was born as a mechanical worker, and as a boss, he used to have to do everything himself.

"Didn't I tell you that with bearing steel GCr15? Why do you use 45 steel? "Yun Fei is speechless.

Bearing steel this thing, the country can also provide, although the price is higher, but do high precision requirements of ball screws and matching ball screw nuts and balls, although the 45 steel processed out of the performance is very close, but the difference is still quite large.

"Soviet engineers said that our No. 45 steel has about the same properties as bearing steel. No. 45 steel is easier to process than bearing steel, especially after heat treatment, No. 45 steel quenching can only reach HRC Rockwell hardness of 48 degrees at most, and even if it reaches that hardness, the material has no toughness, and the ball screw produced in this way will not have much service life at all. Yun Fei shook his head and sighed.

This is the bitter fruit caused by the blank in the domestic industry. Although because of the large demand in the domestic market, there are no competitors; However, it is precisely because of this situation that there are no professionals in this area in China. Starting from scratch is not an easy task.

I told them that the ball screws were made of bearing steel GCr15, but they replaced the material with the cheaper No. 45 steel. Could it be that in this era, no matter what you want to do, you have to stare at it yourself? Especially in terms of CNC machine tools, although there are a lot of people who study this aspect in China, most of them are strictly controlled by the state in the national research institute, and it is impossible to get those who understand not too much. But researchers with a good foundation.

Yun Fei patted his head. He really has a headache, for such a thing, Wang Qingfeng is a very good senior manager, because no matter what the people under him say. As long as it is reasonable, as long as logical reasoning with what is written can convince him, he will agree.

"The Soviets knew what they were talking about, if they really knew that ordinary carbon steel could replace bearing steel. So what are the other types of steel? Yun Fei was noncommittal to Wang Qingfeng's words. It seemed that it was necessary to find an opportunity to take a good lesson with the Soviets.

"Lao Wang, who is in charge of the technique here?" Yun Fei didn't bother to investigate the person responsible for this incident now. Fortunately, it is still in the test stage, and this first production is because it is a test nature, so the quantity is only more than 30 semi-finished products with a length of one meter and five long.

Yun Fei understood that if it weren't for the ball screws they produced this time, they would not be able to meet the accuracy requirements of the design during the grinding process; If it weren't for the Jiuyi Heavy Industry under its own control, it would have been rectified under the auspices of various middle and senior managers during this time; If it weren't for the things produced in the ball screw factory that he partnered with Wang Qingfeng, it would be related to the production of his CNC lathes of Jiuyi Heavy Industry......

If it weren't for many reasons to make me go to the ball screw factory at this time, maybe when the ball screw produced by the ball screw factory in partnership between the two people was put on the market in large quantities, and even many years later, I would not ask what materials the ball screw was used.

In that case, after selling their CNC machine tools to the market, after the customer uses them for a period of time, Jiuyi Heavy Industry will definitely receive snowflake complaints, and at that time, Yun Fei can only cry without tears. Especially in a few years, the domestic CNC machine tool market competition will become fierce.

China has now begun to enter the era of market economy, and it will not be able to wait a few years before joining the World Trade Organization (WTO), and if the quality is not improved, it will have a disastrous impact on the company when it encounters an economic downturn. Customer loyalty, once lost, is not an easy thing to get back.

In this era, China's CNC machine tools, especially domestic CNC machine tools, have always been criticized, the most important is the quality problem. Although the domestic market is now blank, as long as Jiuyi Heavy Industry can produce CNC machine tools, it will definitely occupy a large number of markets soon. But after other manufacturers solved the problem of ball screws, Yunfei's Jiuyi Heavy Industry would continue to shrink because of quality problems, until there was no market share at the end.

Of course, if the price is reduced, in the Chinese market, no matter how garbage CNC machine tools, as long as it is CNC machine tools, there will be a market, after all, many mass-produced parts products, for processing accuracy requirements, is not very high.

"Xiaoyun, this is the current head of the technical department of our factory, Sevianski, the people in the factory call him Dead Chicken......" Wang Qingfeng shouted "Dead Chicken" into the workshop, and saw a middle-aged thin white man in his forties running towards this side.

"Boss, are you looking for me?" Sevyanvsky trotted up to the boss who called him a "dead chicken" and said a stiff Chinese sentence with his stiff tongue, which made Yun Fei extremely awkward to hear.

"Why do I need to use No. 45 steel instead of the bearing steel I chose?" Yun Fei stared at the other party with an unkind face, expecting him to give him a reasonable explanation.

Although these engineers from the Soviet Union have a very good mechanical foundation in their country, once they come here, although Wang Qingfeng gave him the position of head of the technical department, he should not make his own decisions when he has not yet figured out the situation, and change the raw materials he chooses and the process route he has formulated.

There were many differences between the Soviet Union and China, not only in terms of materials, but also in terms of technical standards.

Sevianwski didn't understand Yun Fei's words, stared at Wang Qingfeng with a puzzled face, and saw Wang Qingfeng repeating Yun Fei's words that he couldn't understand, so he could only search around for the translator in the factory, although he had been here for a month or two, but Chinese, for those of them who use letters, square words are not only difficult to recognize, difficult to write, and even pronunciation is extremely difficult.

Wang Qingfeng was depressed, at the beginning, when Sevianwski first arrived here, he told the translator that during work hours, he had to follow the dead chicken, and he couldn't see the translator at this time, where did he, the temporary operator of the factory, put his face in front of another shareholder of the same status as him?

"Through the inquiry of the material grade of the national technical standard formulated by China in 1981, I think that in most cases, No. 45 steel can replace bearing steel......" After Sevianwski translated, he realized that the overly young person in front of him was actually his other boss, and the shares in his hand were not less than the boss who laughed all day long, so he explained to Yun Fei seriously.

"Don't tell us, you didn't analyze the material!" For the goods in front of him, Yun Fei interrupted impatiently, how could he not know how to say that in some not very important occasions, No. 45 steel can replace many materials.

But the production of ball screws is just an important occasion! In particular, ball screws are one of the determining factors for the accuracy of CNC machine tools!

"......" Sevianwski was noncommittal about Yun Fei's words. Such a young man in front of him, twenty years old, how much can he know? Although I have not been exposed to the design and production of high-precision parts such as ball screws, there are many other high-precision parts and products.

"From now on, change it back for me immediately, and you must test and produce it in strict accordance with the materials and production processes I gave at the beginning, otherwise you will go back to your Soviet Union!" Yun Fei saw this dead chicken gritting his teeth, staring at himself with a red face, and he also knew that this thing must think that he might be the second generation of his father who was rich, and he was blindly commanding here.

Yun Fei is angry!

In his world, more than 90% of the materials used in the production of ball screws are made of bearing steel GCr15. This is going to be an experiment, and it will take a long time.

Coming soon into 1993, Taiwan's machine tool manufacturers are about to enter the domestic market in a big way, if they can't achieve absolute advantage in the Chinese market when they build factories, they will definitely fall into a protracted price war.

"The cost problem, you don't need to think about it now, even if No. 45 steel can achieve this effect, there will not be much cost left, and when the time comes, it will cause a lot of trouble to the company because of product quality problems......" Yun Fei saw that although Sevianski agreed, the expression on his face showed that he was not convinced. (To be continued......)

PS: Bow and thank Ah Guang 1 and kgb31 for the big monthly passes, and thank you for the great reward from Ice Marks.