Fusion System: Rebirth in a Courtyard - Bird Fighting Chronicles

Chapter 86 A treacherous scheme is devised to accelerate precision; a clever breakout reveals brilli

The successful forging of high-strength bolts made the precision forging team famous. The factory not only awarded them a 500 yuan bonus and a merit reward, but also specially approved the conversion of the adjacent unused tool room into a dedicated laboratory for the research team. Lin Chen was leading Liu Guangtian, Sha Zhu, and others to check the newly allocated precision measuring tools when a group of people suddenly gathered in front of the workshop bulletin board, and their discussions drifted over like an explosion.

"This specification is way too demanding! Tolerances of no more than 0.01 millimeters? What's the difference between that and embroidery?"

"They specifically requested Lin, a key member, to take the lead, and even appointed Qin Huairu as the technical advisor. Isn't this a joke? Qin Huairu has been an apprentice in the fitter's workshop for two years and hasn't even passed the exam to become a senior technician. Who can she possibly mentor?"

Lin Chen put down his micrometer and strode towards the bulletin board. A task notification, stamped with the red seal of the Technical Department, was prominently displayed in the center. It read: "Lin Chen, a key technical member of the Precision Forging Group, is hereby appointed to lead the processing of a batch of high-precision gear forgings. The material is 20CrMnTi, with a single-piece tolerance of ≤0.01mm. The completion deadline is 72 hours. Technical guidance: Qin Huairu (Fitter Workshop)." The signature "Yi Zhonghai" was bold and powerful, carrying an undeniable air of authority.

Sha Zhu sidled up to Lin Chen, pointing at the words "Technical Instructor" through gritted teeth: "That old bastard is clearly trying to make things difficult for you! Qin Huai can't even hold a basic file properly, and appointing her as instructor is just asking us to make a fool of ourselves!" Liu Guangtian also frowned: "A tolerance of 0.01 millimeters... even the best precision machine tool in our workshop only has a precision of 0.02 millimeters. This is far beyond the equipment's limits!"

Lin Chen's fingertips traced the words "20CrMnTi" on the task sheet. This alloy material is extremely tough and prone to minute deformation after forging. To control it within a tolerance of 0.01 millimeters is equivalent to carving a pattern on a fingernail while ensuring the fineness of the lines is perfect. He looked up towards the fitter's workshop, where Yi Zhonghai was standing in front of the workbench "instructing" an apprentice, but his peripheral vision kept glancing at the notice board, a barely perceptible smirk playing on his lips.

"Master Lin, should we go and complain to Director Zhou? This task is impossible to complete!" Liu Guangfu gripped the wrench, his face flushed red. Lin Chen shook his head, peeled off the task sheet and folded it neatly: "The task sheet is stamped with the technical department's seal, so even if we go to Director Zhou, it won't do any good. Yi Zhonghai just knew we lacked equipment and assigned an incompetent supervisor, wanting us to either fail the task and lose our key positions, or bite the bullet and produce scrap, giving him leverage against us."

As they were talking, Qin Huairu walked over carrying a thick "Fitter's Manual," her face full of embarrassment: "Master Lin, I... I know Master Yi did it on purpose, but he said if I don't come to be the instructor, he'll transfer me to the boiler room to tend the fire. I really have no choice..." Her hands gripped the cover of the manual tightly, her knuckles turning white. The delicate expression she had deliberately cultivated was now filled with genuine embarrassment.

Lin Chen looked at the still-present stitch marks on her wrist and recalled the change in her demeanor when he had advised her to make a living through sewing. He made up his mind: "Master Qin, don't be nervous. Since you're here, help us with whatever you can. Take a look at the blueprints for this batch of gears first, and mark the parts you think are the most difficult to process. We'll discuss it together." He deliberately emphasized the words "Master Qin," his tone devoid of any disdain.

Qin Huairu was stunned for a moment, then her eyes reddened slightly. Ever since she was transferred to the logistics and mending group, the people in the workshop either mocked her poor skills or subtly ridiculed her for living by scheming. This was the first time someone had seriously called her "Master." She quickly flipped open the blueprints, her fingertips tracing the outline of the gear teeth, and said earnestly, "Here, and here, the transition arc at the root of the tooth and the chamfer at the tip of the tooth are the most prone to deformation during forging. If the tolerance is only 0.01 millimeters, even a slight deviation will result in a defect."

Lin Chen's heart skipped a beat. Although Qin Huairu's practical skills were lacking, his understanding of blueprints was quite good, having watched Yi Zhonghai process parts for many years. He immediately convened a meeting of the task force members, spreading the task sheet and blueprints on the makeshift conference table: "If the equipment's precision is insufficient, we'll compensate with the process; for the material deformation problem, we'll control it step by step. Now, we'll split into three groups: Guangtian will lead two people to be responsible for material pretreatment, performing low-temperature annealing on the 20CrMnTi billet to reduce internal stress; Shazhu will go to the warehouse to inventory all available precision measuring tools, especially dial indicators and optical dividing heads, and immediately register any damaged ones; Master Qin and I will be responsible for developing the forging process, focusing on solving the problem of tooth deformation."

After the meeting, Lin Chen led Qin Huairu into the newly renovated laboratory. Although the laboratory only had a second-hand optical projector and a few precision testing instruments, it was much quieter than the workshop. Lin Chen opened the system panel, consumed 100 points to activate the "Process Simulation" function, and the forging curve of 20CrMnTi immediately appeared on the light blue virtual screen.

"Look here," Lin Chen pointed to the temperature nodes on the screen, "20CrMnTi has the best plasticity at 850℃, but it is prone to grain coarsening above 900℃, which leads to subsequent deformation. We used a one-time forming process for forging bolts before, but this time we have to change it to a four-step process of 'preheating-initial forging-precision forging-isothermal cooling,' and the temperature error of each step must be controlled within ±5℃."

Qin Huai leaned closer to the screen, her breathing becoming softer: "But our workshop's forging furnace doesn't have a precise temperature control device. We rely entirely on experience to judge the heat. How can we guarantee such a small temperature error?" Lin Chen took out a modified thermocouple from his toolbox, with a tiny alloy probe welded to the top: "This is a temperature sensor I modified using a scrap thermocouple and the system I exchanged. It's accurate to 1°C. I'll install it in the observation hole of the forging furnace later to monitor the temperature in real time."

As the two were discussing the details of the process, the laboratory door was suddenly pushed open, and Yi Zhonghai walked in carrying an enamel mug. Tea stalks floated on the surface of the mug, emitting a faint musty smell. "Lin, you've got quite the leisurely pace. It's been almost half a day, and the blanks still haven't been put into the furnace?" He glanced at the process sketches on the table, a mocking smile playing on his lips. "I assured the factory manager that you would definitely finish it within three days. If you don't, not only will you lose your key position, but I, as the technical advisor, will also lose face."

Qin Huairu was so frightened that she quickly stood to the side, nervously twisting the hem of her clothes. Lin Chen, however, picked up the temperature sensor on the table and handed it to Yi Zhonghai: "Master Yi, you've come at the right time. Please take a look at this modified thermocouple. The forging temperature window of 20CrMnTi is too narrow. Precise temperature control is essential. If it produces scrap and delays the military factory's order, no one can bear that responsibility."

Yi Zhonghai's gaze fell on the sensor, his pupils contracting slightly. He hadn't expected Lin Chen to be able to modify precision instruments himself. He had thought he could stump Lin Chen by relying on the lack of precision in the equipment, but it seemed he had miscalculated. However, he still tried to remain calm: "Don't bother with these fancy things. We technicians rely on our skills. Back in the day, I processed parts with even higher precision than this, relying entirely on my eyes and touch."

"Master Yi is right," Lin Chen said, calmly retracting the sensor. "However, times are changing. In the past, we relied on experience; now we rely on a combination of technology and experience—a double guarantee for greater security. By the way, Master Qin just pointed out a problem with the tooth root transition arc on the drawing. I think it's crucial. With your extensive experience, could you give us some advice?"

Yi Zhonghai was taken aback when Lin Chen brought up Qin Huairu, leaving him speechless. He hadn't even looked at the blueprints carefully, let alone understood the problem with the tooth root arc. If he rambled on, he would only make himself look foolish. He coughed twice, put down the enamel mug, and said, "I have other things to do. You can work on it slowly. If you really can't figure it out, tell me as soon as possible so I can inform the factory manager in advance." With that, he hurriedly left the laboratory, his steps much more flustered than when he arrived.

Watching Yi Zhonghai's retreating figure, Qin Huai breathed a sigh of relief: "Thank you, Master Lin. I was really afraid he would make things difficult for me." Lin Chen smiled: "He's just a paper tiger. As long as our skills are solid, he won't find any fault with us. The issue of the tooth root radius you mentioned earlier is crucial. Could you explain it to me in more detail?"

It turns out that although Qin Huairu wasn't good at practical operation, she had watched Yi Zhonghai process gears for many years and had a good understanding of gear failure modes. Pointing to the tooth root area on the drawing, she said, "Master Yi used to say that the tooth root was prone to breakage when processing gears, especially when the transition radius was too small. If we make the tooth root radius slightly larger than required by the drawing during forging, it can reduce deformation and improve the strength of the gear. I just don't know if it will affect the precision."

Lin Chen's eyes lit up; this was precisely the crucial point he hadn't considered. While 20CrMnTi possessed good toughness, the tooth root, as a stress concentration area, was indeed prone to fracture due to minute deformation after forging. He immediately activated the system's "process simulation" function, inputting the parameter "increase the tooth root radius by 0.005 mm." The simulation results instantly appeared on the virtual screen: the deformation rate decreased by 60%, the tolerance control range expanded to 0.012 mm, and the strength increased by 15%.

"Great!" Lin Chen slapped the table. "Let's go with this approach! We'll make the forging die according to the modified parameters first, and then use a finishing process to adjust the precision after the initial forging is completed. Master Qin, could you draw a revised drawing of the forging die for me? Make sure the transition of the tooth root arc is smooth." Qin Huairu nodded vigorously, her hand holding the drawing pen no longer trembling, her eyes full of enthusiasm.

At this moment, Liu Guangtian and Sha Zhu returned, bringing bad news: only one dial indicator in the warehouse was working properly, and the lens of the optical dividing head was scratched, which would affect the measurement accuracy. Sha Zhu stamped his feet anxiously: "Should I go and talk to He Yushui and ask her to borrow a set from Li Jianguo?" Lin Chen shook his head: "There's no time. We'll fix it ourselves."

He led Sha Zhu to the warehouse and carefully inspected the lens of the optical indexing head. The scratches weren't too deep; polishing compound should be able to repair them. However, polishing requires extreme patience, and the lens could be damaged if not handled carefully. Sha Zhu volunteered, "I'll try. I used to polish pots and pans in the cafeteria; I'm very skilled at it." Lin Chen handed her the polishing compound and a chamois cloth with some skepticism, instructing her, "Be gentle, rub slowly in a clockwise direction, and wipe it clean with alcohol every minute to check."

Meanwhile, Liu Guangtian had completed the low-temperature annealing of the material and neatly arranged the billets next to the heating furnace. Lin Chen installed the modified temperature sensor on the forging furnace, and the red digital display immediately showed the furnace temperature: 25℃. He pressed the heating button and said to Liu Guangtian, "Notify me when the temperature reaches 800℃. We'll preheat it first and control the temperature uniformity of the billets within ±3℃."

As night fell, only the lights in the precision forging group remained on in the workshop. Lin Chen was adjusting the forging die when Qin Huairu approached with a bowl of hot porridge. "Master Lin, have something to eat. I brought it from home, with some sweet potato added; it'll keep you full." Lin Chen took the bowl, the warmth spreading from his fingertips to his heart. The sweet potato in the porridge was soft, sweet, and fragrant, clearly carefully cooked.

"Thank you, Master Qin." Lin Chen took a sip of porridge. "Once this batch of tasks is completed, I'll talk to Director Zhou about transferring you back to the precision group. Your understanding of the blueprints is excellent; you'd be perfect as a process engineer." Qin Huairu's hand suddenly froze, tears welling up in her eyes. "I...can I really do it? I schemed against you and Sha Zhu so much before, don't you blame me?"

Lin Chen put down his porridge bowl and said earnestly, "The past is the past. Everyone has their difficulties. You make a living with your sewing skills and are willing to sincerely help us solve technical problems. That's better than anything else. In the technical industry, you earn your living with your skills and don't care about the past." Qin Huairu nodded vigorously, wiped away the tears from the corners of her eyes, and turned back to checking the blueprints.

At 2 AM, Sha Zhu finally repaired the optical indexing head. After testing, the measurement accuracy reached 0.001 millimeters, fully meeting the requirements. At that moment, the furnace temperature also reached 800℃. At Lin Chen's command, Liu Guangtian immediately placed the billet into the furnace. The temperature sensor readings kept jumping: 800℃, 820℃, 850℃… When the number stopped at 850℃, Lin Chen shouted, "Take it out of the furnace!"

Sha Zhu swiftly used pliers to pull out the scorching hot billet, its entire surface a bright red, radiating intense heat. Lin Chen, holding a forging hammer, focused intently like an eagle, each strike of the hammer on the billet precise and powerful. "Clang! Clang! Clang!" The crisp sounds echoed in the silent workshop as the billet gradually took shape in the forging die, the excess flash being precisely knocked away.

"First forging complete, proceed with isothermal cooling!" Lin Chen placed the forged gear blank into an insulated box lined with thick asbestos cloth, maintaining the temperature at around 300℃. Isothermal cooling effectively reduces internal stress in the material, preventing deformation during subsequent finishing. During the cooling interval, Lin Chen instructed everyone to prepare finishing tools, fixing the dial indicator to a special stand and adjusting it to its optimal state.

The next morning, Yi Zhonghai brought the technical department staff to the workshop for an "inspection." Seeing that the insulated boxes hadn't been opened yet, he immediately said sarcastically, "Lin, it's been almost a day, why haven't we finished the product yet? Are you having some problems? If you can't do it, just say so, I'll get the fitter's workshop to help, so as not to delay the deadline."

Lin Chen ignored him and simply glanced at the temperature display on the insulated box: "The temperature has just dropped to room temperature, it's ready for finishing." He opened the insulated box and took out the gear blank. The blank, after isothermal cooling, was silver-gray in color and showed no signs of deformation. Lin Chen fixed the blank onto the optical indexing head and started the finishing machine. Tiny metal shavings fell into the chip collection tray like snowflakes.

Yi Zhonghai moved closer to the optical projector, staring intently at the gear outline on the screen. The tooth lines on the screen were clear and smooth, with a natural and smooth transition arc at the tooth root. When the dial indicator reading showed 0.008 millimeters, his face instantly turned deathly pale—this precision not only met the mission requirements but also exceeded the specified tolerance by 0.002 millimeters.

"Impossible! Absolutely impossible!" Yi Zhonghai shouted in a panic. "You must have secretly switched the billet or altered the measurement data!" The technical staff quickly stepped forward to remeasure, and after three measurements by different people, the result was consistently 0.008 millimeters. Old Chen, who was in charge of the inspection, shook his head: "Master Yi, this precision is fine, it's even higher than our technical department's standard."

Lin Chen put down his tools and said calmly, "If Master Yi doesn't believe me, he can test it himself. We adopted a four-step forging process and isothermal cooling technology, and also optimized the transition arc of the tooth root, which not only improved the precision but also enhanced the strength of the gear. Master Qin and I researched this together. If Master Yi is interested, I can show you the process report."

Yi Zhonghai stared at the thick process report in Qin Huairu's hand, which detailed the process parameters and test data for each step, along with clear simulation curves. He knew that not only had he failed to stump Lin Chen this time, but he had actually helped Lin Chen advance his technical skills to a higher level. He trembled with anger, yet couldn't find any reason to refute it, so he could only wave his hand awkwardly: "Now that it's finished, hurry up and report it to the factory management. Stop showing off here."

Watching Yi Zhonghai slink away, a burst of enthusiastic cheers erupted in the workshop. Sha Zhu hugged Lin Chen tightly: "Master Lin, you're awesome! Now let's see if that old bastard dares to mess with us again!" Liu Guangtian and Liu Guangfu also excitedly high-fived, and Qin Huairu looked at the process report in her hand, a long-lost confident smile appearing on her face.

Lin Chen picked up a finished gear. Sunlight streamed through the workshop windows, illuminating the gear and making the outline of the teeth clearly visible. Each tooth looked like a meticulously crafted work of art. He knew that this victory was not only a technical success but also a victory for humanity. Yi Zhonghai's schemes were ruthless, but as long as they adhered to their original aspirations in technology and united the forces around them, no difficulty was insurmountable.

That afternoon, the factory received the task completion report from the precision forging team. The factory director personally visited the workshop, and after seeing the finished gears and the detailed process report, he immediately praised Lin Chen, saying, "Comrade Lin Chen not only completed the task but also optimized the forging process. This spirit of dedication is worthy of emulation by the entire factory! I have decided to award the precision forging team another collective merit, and add another 300 yuan to their bonus!"

When the news reached the courtyard, Liu Haizhong specially bought firecrackers and set them off at the gate. The crackling sound of the firecrackers made the whole courtyard boil with excitement. Qin Huairu, holding the "Process Optimization Contribution Award" certificate issued by the factory, excitedly said to Jia Dang, "Mother has a certificate too! From now on, Mother can earn a living with her skills and will no longer have to look down on others!" Jia Dang hugged his mother's neck, his eyes narrowing into slits with laughter.

Only the lights in Yi Zhonghai's house remained off all day. Looking at her husband's ashen face, Aunt Yi cautiously advised, "Old Yi, let it go. Lin Chen is indeed capable; let's not antagonize him anymore." Yi Zhonghai slammed the teacup on the table to the ground, spilling tea everywhere. "I'm not reconciled! I've been a technical authority my whole life, and I've lost to a mere brat!" The shards of the teacup scattered across the floor, like his broken pride, never to be pieced back together.