Chapter 843: Vigorously miracle

After hearing Tan Zhenhua's question, Shen Hong sighed.
He was silent for a moment before shook his head slightly and said, "Mr. Tan, I want to tell you that the same equipment can have completely different effects in the hands of different people. The factors that affect die forging manufacturing are not only the tonnage of the equipment. It also includes die forging process and die forging materials. The early die forging process was direct cold forging and pressing of metal blanks, and I think the latest international technology has been developed to multi-directional hot forging, isothermal forging, and powder die forging. Forging, liquid die forging, closed die forging, superplastic forming precision die forging and other methods, die forging materials have also developed to copper-aluminum alloy, aluminum-magnesium alloy, aluminum-lithium alloy, nickel-based alloy, rare earth element alloy, titanium alloy, etc. The Americans’ technology is absolutely leading in this regard. They have the ability to use 45,000-ton presses to make C-5 Galaxy, Boeing 747, Saturn 5, and even large alloy forgings on the latest nuclear-powered aircraft carriers. Forging. For example, for a large passenger aircraft such as the Boeing 747, I heard that its four main landing gear forgings are actually manufactured with a 30,000-ton die forging press. This fully demonstrates their leadership in materials and technology."
Shi Changxu rarely inserted a sentence: "I probably know some of the reasons. The high-temperature mold level in the United States is currently the world's most advanced. For example, the same part can be forged at 1700 degrees, while China currently can only Forging at 1000 degrees, and the metal has to be processed into the same internal structure characteristics at these two temperatures, the required forging force is completely different, so it can be done easily and happily with a 30,000-ton forging machine, and we use Huaxia Forging machines of the same tonnage cannot do it. If you want to do it, you can only do miracles with a forging machine of larger tonnage."
Master Master’s words are getting more and more incisive!
Tan Zhenhua sighed and nodded again. Now, he finally sorted out some context.
From Shen Hong’s words, he already knows that although Huaxia is not leading in die forging tonnage, it is at least still in the top position, but it is far behind the world’s advanced in materials and new forging technology. horizontal.
He asked again: "Shen, you have introduced so much just now. The kid has been taught today. However, you did not introduce the level of Britannia’s current die forging hydraulic press. Also, can you help me infer that, Do we have enough equipment to build a BAC-level passenger plane?"
"I knew you would ask this question." Shen Hong smiled slightly: "Let me first introduce the situation of Britannia's die forging hydraulic press. Actually, Britannia is the inventor of the die forging press. According to Pascal's principle, Due to the fluidity of the liquid, the pressure change of a certain part of the static fluid in the closed container will be transmitted in all directions. This is the theoretical basis of the hydraulic press. As early as 1795, the British engineer Bula Mo invented the first practical hydraulic press. This hydraulic press has a three-beam and four-column structure, and this classic structure is still in use today; in 1967, a 30,000-ton multi-directional die forging hydraulic press built by the British Cameroon Iron and Steel Company was put into production , If I remember correctly, this should be the largest die forging hydraulic press in their country. The aircraft you mentioned, the load-bearing structural parts in it, should be forged by this press."
"Our die forging is also 30,000 tons, so it should be enough, right?" Tan Zhenhua asked with joy.
"Sufficient, but not enough." Shen Hong gave an ambiguous answer, and Tan Zhenhua did not need to ask. He then explained: "It is impossible for us to produce 30,000 tons of parts that others can produce. Come out, and I have seen the information of your aircraft. The maximum take-off weight is only 55 tons, the length is about 38 meters, and the diameter is only 3.16 meters. This size is not even compared with the "Yunshi" with a take-off weight of 110 tons. There is no "H6" with a takeoff weight of 75 tons. We can build H6. Of course you can also make a passenger plane."
"Then why is it not enough for you to say it?"
"It's because of the largest forging size and precision." Shen Hong replied helplessly: "The die forging of Southwest Aluminum Plant was completed in 1966, but it was not officially put into production until 1970. Mr. Tan, you should know that during that period. What's the situation?"
After being brought back to that helpless historical period, Tan Zhenhua had no choice but to answer in silence.
Shen Hong continued: "Although this die forging machine is also a good son of mine, I have to admit that it has many inherent shortcomings. Among them, there are two things that I regret most. One is that it failed to achieve the best forging. The other dimension is its accuracy."
Shen Hong did not evade the problem, but rather frankly said: "To be honest, in that era, being able to successfully build it and basically reach the design index is already the limit I can achieve, and I can no longer do more. Pursue, but this will bring some troubles to the future production-the size of the parts that can be processed is limited, and the accuracy is insufficient. The main bearing beams of large aircraft can not be forged at one time, and the common parts of our fighter jets Many of the problems of poor fitability and low versatility lie here."
This is considered to have found the root cause. The two most criticized faults of the "Yun Ten" and the two most important reasons for opposing the "Yun Ten" project are actually derived from this.
Objectively speaking, neither of these two faults is really acceptable.
The user requirements of civil aircraft and military aircraft are fundamentally different. Are they military-used? High cost and troublesome repairs can all be done. Moreover, according to China's current situation, these aircraft cannot be shipped out of the country even if they are scrapped. I can bear it. At most, the military's ground support department will greet the elders in the family several times...
However, civil airliners have almost zero tolerance for these two problems.
Use welded girders? Are you kidding me, who will bear the responsibility if there is an accident? Even if the structure is strong enough, it must gain a lot of weight, right? Gaining weight means consuming more fuel, which will end the life of the airline... Besides, your plane is sold. Who knows when it will fly on which corner of the earth? If it breaks, your standard parts are not standard, how can this be repaired? Is it possible that you have to equip each aircraft with a dedicated spare parts library? Which company can afford such high maintenance costs?
"Then is there a cure for this disease?" Tan Zhenhua asked with a glimmer of hope. After all, this problem was brought from the womb, and it didn't sound like a cure.
"It's almost impossible to heal." Shen Hong frowned and replied: "Unless a few important parts of them are removed and rebuilt-with the effort and money to remove, then you might as well build a new one. The best way now is to transform and upgrade some of the parts that are not important but have a greater impact on the processing size and accuracy. After the current technical means are transformed, it is possible to make it work in the best state, in my opinion , This should also meet the requirements."
Tan Zhenhua pondered for a long time before gritting his teeth and asked: "Then, Mr. Shen, how long will this transformation take and how much will it cost?"
When he finished asking this question, he saw Shen Hong and Shi Changxu looking at each other, and a flash of light flashed in his eyes
A glimmer of enlightenment flashed across his mind.
not good!
Inadvertently, fell into the pit!