In addition to admiration, everyone looked at Li Tianfeng with a little worry, worried that Li Tianfeng had messed up on how to fix the oil leak.

Seeing that everyone was looking at themselves worriedly, Yang Xianfeng was also looking at himself, as if he was waiting for his next plan, Li Tianfeng smiled slightly, and said confidently: "Mr. Yang, the second step is how to repair the oil leak." ”

"Hmm." Yang Xianfeng nodded, waiting for Li Tianfeng to continue and come up with his own solution.

In the eyes of many people, the repair work is not simple, because we basically know that the oil leakage is in the inner cavity of the combustion chamber casing, and the inner cavity structure is complex, and the welding torch cannot enter at all.

Could it be that Li Tianfeng has another plan, not a repair plan using repair welding, everyone looked at Li Tianfeng expectantly, waiting for Li Tianfeng to continue.

Li Tianfeng smiled slightly, sorted out his thoughts and said: "Everyone knows that the oil leakage is in the inner cavity of the combustion chamber casing, and our welding torch can't get in at all, but we can cut a small window into the combustion chamber casing, and after the repair welding is completed, we will re-weld this small opening." ”

Hearing this, everyone was stunned, there was such a repair plan, everyone heard of such a plan for the first time, at first, everyone thought that Li Tianfeng was going to use other plans for repair, but they didn't expect to use such a bold repair welding plan.

Repair welding is for sure, some parts inside the combustion chamber casing, including these oil lines, are welded, and it is only appropriate to repair them with repair welding.

Such a repair plan, in Li Tianfeng's memory, is a very mature plan, and there is enough theoretical support, even including repair welding parameters, welding deformation parameters, deformation calculations and other theories, because he has the goods in his heart, so Li Tianfeng is full of confidence.

Walking to the front of one of the burner casings, Li Tianfeng pointed to a position and said, "Cut a small window from here, if my estimate is correct, one of the lubricating oil pipelines inside is unwelded, and after the lubricating oil pipeline is repaired, this small window will be repaired." ”

Seeing that everyone looked at him in astonishment, Li Tianfeng said: "Of course, I still have to go through detailed calculations for the size, specific location, welding parameters, etc. of the cutting window, and after I have calculated it, I will tell everyone one by one." ”

One of the white-haired, old-looking experts said, "Expert Li, won't this welding be deformed?" In the unlikely event that the welding deformation affects the precision holes closest to the repair welding position, or the bearing mount, the entire casing will be wasted. ”

Li Tianfeng said: "Therefore, I still have to go through calculations, calculate various process parameters, and then operate in strict accordance with the process, so that welding deformation will not be caused, and a qiē will be within a controllable range." ”

Yang Xianfeng also heard such a plan for the first time, and was a little worried, after thinking about it for a while, he decided to take a more secure plan, so, Yang Xianfeng said: "Tianfeng, do your best to calculate all kinds of parameters, prepare detailed process operation procedures, Director Xu, Director Deng, you will do the preparation of specific process regulations, and Tianfeng will provide technical guidance." ”

"Okay, no problem." Xu and Deng, the two directors and deputy directors of the sheet metal workshop, said in unison.

After thinking about it, Yang Xianfeng continued: "We have a few scrapped turboprop B combustion chamber casings, first try them with the scrapped casings, if there is no problem, then implement them on these casings to ensure that nothing goes wrong, in addition, after the repair welding repair, then carry out verification and commissioning." ”

The so-called verification test is because the aero engine adopts one or more new processes, new designs, and even new materials, and then tests the engine in order to verify the feasibility of these new processes, new designs, and new materials.

The scrapped casing is used for testing, then the formal combustion chamber casing is repaired, and finally the verification test is carried out. In this way, it is more secure.

Everyone also agreed to such a plan, and the matter was settled.

Afternoon.

Li Tianfeng was not idle, carefully calculated various process parameters, guided the sheet metal workshop to compile detailed process regulations, and in the afternoon of the same day, he also carried out a test on a scrapped turbine casing, that is, process verification.

The effect of process verification is very good, very successful, Director Xu of the sheet metal workshop, Director Deng looked at Li Tianfeng's eyes were obviously different, and thought in his heart, it was really worthy of the name, and his attitude towards Li Tianfeng was even more enthusiastic.

The next day, the three or so combustion chamber casings that had leaked oil were officially repaired.

The restoration site was lively, Yang Xianfeng, Liu Qingshan, and a large number of technical experts and technical backbones, everyone came and formed a big circle.

Several workers and masters are fully armed and wearing strict uniforms. Under the guidance of Li Tianfeng, the fitter master carefully marked the line in the part that needed to open the window, and after the marking was completed, he held the cutting machine in his hand and carried out the cutting operation in Li Tianfeng's knowledge.

The emery wheel of the cutting machine rotated at high speed, making a screeching sound, sparks splashed, and a small window the size of half a palm gradually took shape, and the fitter master skillfully cut out this small window, and then put aside the cut half a palm-sized superalloy sheet.

The combustion chamber casing is a high-temperature alloy sheet metal part, which is welded by high-temperature alloy parts, and Li Tianfeng is more familiar with this grade of high-temperature alloy, and the calculated parameters will not be wrong.

This piece of superalloy that is half the size of a palm will have to be repaired and welded again, and it will still be welded in the original position.

opened a small window that slapped everyone, Li Tianfeng took a small flashlight, shone it along this small window, and soon saw the oil pipeline that had been desoldered, Li Tianfeng said: "Everyone come and take a look, the fault of the oil leakage is here." ”

Soon, everyone gathered around, looked inside, and saw the situation clearly.

"Really, desoldered."

"Yes, maybe the welding quality was not up to par at the beginning, the engine was vibrating, and the fault came out."

"Well, it's also possible that the air salt content over there is relatively high, which corrodes this solder joint."

"Look, there's a little crack in the weld here, and that's where the oil leaks."

Everyone gathered around, while watching, while saying their own opinions, everyone is an expert or technical backbone, as soon as they see this fault site, they basically understand what is going on.

Yang Xianfeng and Liu Qingshan also came over to take a look, and then the two glanced at each other and nodded.

After everyone finished reading it, the fitter master said: "Expert Li, can you do the grinding and cleaning work before welding now?" ”

"Yes." Li Tianfeng nodded.

The fitter master has long been convinced by Li Tianfeng, yesterday afternoon, when the process verification was carried out with the scrapped combustion chamber casing, Li Tianfeng's watch Xiàn made the experienced fitter master admire it, and now, the fitter master is completely obedient to Li Tianfeng's words.

In order to ensure the quality of welding, it is necessary to polish and clean the repair welding part before welding, the fitter's skill is good, and the part that needs to be polished is polished by hand, and then this part is cleaned with detergent.

"Master Ding, it's time for repair welding." Li Tianfeng commanded.

Master Ding is a welding master, and he also admires Li Tianfeng very much, and when he got the order, he immediately confirmed the repair welding parameters carefully, and after confirming that they were correct, he immediately started the repair welding, and the repair welding was very fast, because only a few spot welds were enough.

"Expert Li, the dewelded oil pipeline has been repaired, you can check it." Master Ding said, and also used the honorific title "you".

Li Tianfeng carefully checked it, and after confirming that it was correct, he instructed Master Ding to start repairing and welding the half-palm-sized window that had just been cut, and various process parameters had already been calculated, and the scrapped combustion casing was used for technical verification, and Master Ding welded it in an orderly manner.

This welding process is a little longer, and the whole welding process is quiet, if it is not for the strong light of the welding arc, everyone will definitely watch the completion of the whole welding process in person.

"Expert Li, the welding is complete, you can take a look again."

Hearing this, Li Tianfeng walked over quickly, looked at it seriously, nodded, and admired Master Ding's craftsmanship a little in his heart, the entire weld was beautiful and neat, which represented solid welding skills.

"Well, yes, very good." Li Tianfeng nodded with satisfaction, and then said: "Then heat treat the surface and relieve the stress." ”

Specifically, how to eliminate the stress caused by repair welding, Li Tianfeng naturally has a set of plans, and has long guided the sheet metal workshop welding to compile a detailed surface heat treatment process.

Of course, this is only a local surface heat treatment, only for the area that has just been repaired, and the operation is also carried out by an experienced worker.

Li Tianfeng himself is a little envious of the E factory, a military industrial enterprise that was built as a key national construction during the First Five-Year Plan period, although the current level of production of various types of aero engines is indeed not very good, but the E factory has a large number of skilled and experienced workers.

There are some workers, from the beginning of entering the factory to retirement, decades of experience, that technical level, sometimes, Li Tianfeng has a little admiration.

Li Tianfeng thought in his heart, his own Tianfeng Technology Co., Ltd. has also begun to start-up, how to gather a group of skilled technical workers, is an important problem that he will solve.

Local surface heat treatment, that is, local aging plus annealing, eliminates the stress caused by repair welding without affecting the properties of the superalloy.

This stress must be eliminated, because if it is not eliminated, it may not be visible now, but after the use process of the later launch, this stress will be slowly released, and over time, with the release of stress, it will cause the deformation of the combustion casing.

Once the combustion casing is deformed, it can lead to catastrophic accidents with unimaginable consequences.

……

Note: The above repair plan of the combustion casing is absolutely true, and it is definitely not made up by Shell, or taken for granted after checking the information on the Internet, this set of repair plan for oil leakage of the combustion chamber casing, Shell personally participated in the whole process, from the program demonstration, to the process verification, to the formal implementation, until the final verification test run has been involved.