Fusion System: Rebirth in a Courtyard - Bird Fighting Chronicles

Chapter 87: Forging Extraordinary Models to Break Limits, Ingenious Craftsmanship Showcases Brillian

The factory's commendation notice was still posted on the precision forging group's bulletin board, the red background and yellow lettering of the certificate making the entire workshop brighter. But Lin Chen didn't relax at all; he was squatting on the cement floor of the laboratory, sketching the structural diagram of the forging die with white chalk. More than a dozen discarded drawings were scattered on the ground, and the "core cavity" part circled in red on the top one had been repeatedly erased and rewritten until the original lines were almost unrecognizable.

"Master, the alloy materials have all been categorized according to your requirements. The 20CrMnTi billet has undergone three low-temperature annealing processes, and the internal stress test report is here." Liu Guangtian walked in carrying a stack of test reports, a few specks of rust-preventive oil still on his forehead. He placed the reports on the makeshift workbench, his gaze falling on the sketch. "The cavity design of this forging die is far too complex! Ordinary gear forging dies are one-piece designs. Won't there be gaps when assembling this segmented structure?"

Lin Chen straightened up, rubbed his aching back, and picked up the report to examine it carefully. The stress curves on each page were as smooth as a lake surface, clearly indicating that Liu Guangtian had put considerable effort into the material pretreatment. Pointing to the segmented lines on the sketch, he explained, "20CrMnTi generates extremely strong radial tension during precision forging. The cavity of a monolithic forging die is easily deformed by this tension, but the segmented structure can offset it through elastic buffering. The key lies in the mortise and tenon structure at the joints. I designed a wedge-shaped interlocking mechanism, controlling the gap to within 0.002 millimeters—finer than a hair."

Sha Zhu walked in carrying a chipped enamel basin filled with noodle soup he'd just gotten from the canteen, along with two poached eggs. "Eat first! I've only had two cornbread buns since yesterday; if I keep going like this, my body will break down." He placed the noodle soup in front of Lin Chen, the steam carrying the aroma of scallions. "I calibrated the optical dividing head three more times, keeping the error within 0.001 millimeters, guaranteeing it's even more accurate than the factory's metrology lab."

Lin Chen was indeed hungry, and he took the noodle soup and wolfed down a couple of mouthfuls. After the hot soup went down, his fingers, which had been frozen stiff, finally regained some feeling. He looked at Sha Zhu's calloused hands and remembered how the other man had squatted in the warehouse last night, polishing the optical indexing head with a deerskin cloth—for four whole hours, Sha Zhu hadn't dared to breathe loudly, and the beads of sweat dripping from his nose onto the lens had almost made him jump out of his skin.

"Oh, right, Master, Master Qin just went to the warehouse and said she wanted to find some old forging dies that were scrapped before, to see if we could salvage some parts." Sha Zhu suddenly remembered this. "She also said that the mortise and tenon structure you designed is a bit like the way old carpenters make furniture. She saw her grandfather make similar wooden molds when she was a child."

Lin Chen's heart skipped a beat. Qin Huairu's grandfather had been a renowned silversmith in the capital, skilled in crafting intricate silver molds. The mortise and tenon joinery technique used in this traditional craft might indeed offer inspiration for forging mold design. He put down the enamel basin and strode towards the warehouse. From afar, he saw Qin Huairu squatting beside a mountain of old molds, carefully cleaning the cavity of a rusted forging mold with a small file. Her cotton-padded jacket sleeves were rolled up to her elbows, revealing rust on her wrists, and her once meticulously manicured fingernails were now filled with grease.

"Master Qin, have you found a suitable one?" Lin Chen walked over and asked.

Qin Huairu raised her head, her face smeared with black ash, making her look like a cat with a dirty face. She held up the forging die in her hand, her eyes shining with excitement: "Master Lin, look, this old bevel gear forging die has a crescent-shaped reinforcing rib around the edge of the cavity. Can we add a similar structure at the joint of the split forging die? It can increase strength and guide the metal flow, reducing deformation."

Lin Chen took the forging die and sanded away the rust. Sure enough, the reinforcing ribs along the cavity edge were exquisitely designed, with smooth, natural curves—precisely the key area he had been struggling with in the sketch. Traditional silversmithing molds use reinforcing ribs to control metal filling to ensure fine details; this approach could be perfectly applied to gear forging dies. "Excellent! Master Qin, you've given me a real eye-opener!" Lin Chen exclaimed excitedly. "We can add three curved guide ribs to the inside of the cavity of the segmented forging die, allowing the 20CrMnTi to flow along the ribs during forging, ensuring a full tooth shape while also mitigating some of the deformation stress."

Qin Huairu was a little embarrassed by his praise and lowered her head to continue cleaning the forging mold: "I was just thinking about it. I used to watch my grandfather make silver locks and he always said, 'The tendons should be smooth and the lines should be even.' I never thought it could be applied to forging molds." She paused and lowered her voice, "I used to think that I could get benefits by pretending to be pitiful, but now I know that the feeling of helping others with my skills is more reassuring than anything else."

Lin Chen patted her on the shoulder: "From now on, we'll work together to research technology and earn our living through our skills. Once this forging die modification is complete, I'll apply to Director Zhou to have you take charge of reviewing the process drawings full-time. You're absolutely capable of doing this job well."

When the two returned to the lab carrying the old forging die, the Liu brothers had already prepared all the necessary materials. High-strength alloy steel plates, heat-resistant steel welding rods, and a few scraps of tungsten steel that Lin Chen had specifically asked Old Wang at the scrap yard to keep—these were all key materials for making the forging die. Lin Chen laid out the optimized drawings on the workbench and marked the key points with a red pen: "Guangtian, you are responsible for machining the segmented cavity using a wire EDM machine, and the accuracy must be controlled within 0.005 millimeters; Guangfu, you and Master Qin will grind the curvature of the guide ribs, and you must use a template for comparison, and the error cannot exceed 0.003 millimeters; I am responsible for making the mortise and tenon joint structure and the water cooling channel."

With the tasks assigned, everyone immediately got to work. The workshop was filled with the hum of machine tools, yet everything was remarkably orderly. When Liu Guangtian operated the wire EDM machine, his eyes were practically glued to the observation window, stopping to measure every 0.5 millimeters cut. Liu Guangfu and Qin Huairu, on the other hand, used specially made templates to meticulously polish the guide ribs, changing sandpaper after sandpaper until the templates were perfectly fitted. Lin Chen was drilling water-cooling holes in the forging die; a 3-millimeter diameter hole required drilling through a 5-centimeter-thick alloy steel plate, and he held the drill bit with a wrist as steady as if it were fixed to the machine tool table.

Around noon, Yi Zhonghai, accompanied by two apprentices, "passed by" the precision assembly workshop. Seeing everyone bustling about, his brow furrowed. "Lin, how's the progress? There are less than forty hours left until the deadline. We can't afford to run out of finished products." His gaze swept over the forging die parts on the workbench, a hint of disdain on his lips. "Can these segmented contraptions even be of any use? Back when I was making high-precision forging dies, I always used integral forging. These fancy-looking things of yours are probably all show and no substance."

Lin Chen was welding a water-cooling channel, sparks flying and burning his face. Without looking up, he said, "Master Yi is very experienced, but 20CrMnTi has special properties. The deformation rate of the overall forging die exceeds 0.02 mm, which does not meet the requirements of the task. Our segmented structure, after system simulation, can control the deformation rate within 0.008 mm."

"System simulation?" Yi Zhonghai scoffed. "Young people are obsessed with these empty concepts. Forging relies on practical skills, not just theoretical knowledge. Let me be clear: if your so-called new structure produces defective products and delays the military factory's orders, can you take responsibility for that?"

Qin Huairu put down the sandpaper in her hand, stepped forward and said, "Master Yi, we have already done three small-batch trial forgings, and the deformation rate has been controlled within 0.01 millimeters. We have test reports to prove it. Moreover, the guide rib design of this forging die is based on the process of traditional silversmith molds, so there is no problem with its stability." She handed over the test forging test report, her tone firm, no longer showing the timidity of the past.

Yi Zhonghai took the report, quickly flipped through a few pages, and his expression grew increasingly grim. The data in the report was detailed and accurate; the deformation curves for each trial forging were clearly visible, even more precise than the experimental data he had obtained years ago. He forced a calm demeanor and handed the report back to Qin Huairu: "Even if the trial forging goes well, we don't know how it will go with mass production. I advise you not to be too overconfident. If things really don't work out, use my old method. Don't force it." With that, he left dejectedly with his apprentices.

Watching Yi Zhonghai's retreating figure, Sha Zhu spat, "That old bastard can't stand to see us doing well. Master, let's hurry up and assemble the forging mold, let's show him what we're made of!"

Lin Chen nodded. Assembling the segmented forging mold was the most crucial step, requiring the three segmented modules to be precisely spliced ​​together using mortise and tenon joints and then secured with high-strength bolts. He and Liu Guangtian each held a torque wrench, tightening the bolts in a diagonal sequence, measuring the gap between them with a dial indicator after each turn. "Tighten the left side by half a turn, the gap is still 0.001 millimeters." Lin Chen stared at the dial indicator reading, his tone steady as a bell. Liu Guangtian held his breath, slowly turning the wrench, sweat dripping from his cheeks onto the ground, leaving a small wet patch.

When the last bolt was tightened and the dial indicator reading stabilized at 0.0008 millimeters, a suppressed cheer erupted in the laboratory. Qin Huairu took out a pre-prepared alcohol swab and carefully wiped the cavity of the forging die, ensuring there was not a trace of impurity. Sha Zhu then placed the preheated 20CrMnTi billet into the heating furnace, and the red temperature display screen continuously jumped, steadily rising towards the target of 850℃.

Night fell again, and the workshop lights were even brighter than the night before. Lin Chen stood in front of the forging press, his eyes fixed intently on the control panel's display screen. Qin Huairu was in charge of monitoring the temperature, while the Liu brothers were guarding the cooling area; everything was ready. "Temperature reached 850℃, it's ready to be taken out of the furnace!" Qin Huairu's voice trembled slightly.

Sha Zhu swiftly used pliers to clamp the scorching hot billet out. The red-hot billet gleamed with a metallic sheen under the light, like a piece of burning gemstone. Lin Chen pressed the start button on the forging press, and the massive pressure head slowly descended, precisely aligning with the cavity of the forging die. "Bang!" A dull impact echoed through the workshop as the billet was instantly formed in the forging die, and the excess flash was precisely extruded.

"Forging complete in one go, proceed with isothermal cooling!" Lin Chen shouted, and everyone immediately sprang into action. After placing the forged gear blank into the insulated box, Lin Chen realized that his back was soaked with sweat, his close-fitting shirt clinging tightly to his body. Qin Huairu handed him a bottle of water: "Master Lin, take a break, it'll take an hour to cool down."

Lin Chen took the water, took a sip, and his gaze fell on the forging mold on the workbench. This "masterpiece," a culmination of everyone's hard work, still had metal shavings from the forging process clinging to its outer shell, yet it shone exceptionally brightly. He suddenly recalled the night of his rebirth, the scene of his first fusion of scrap metal in the storage room. Back then, he was simply trying to survive, but now, he had not only established himself but was also fighting alongside a group of former "opponents."

An hour later, the cooled gear blank was removed. Lin Chen fixed it onto the optical indexing head and started the inspection program. The three-dimensional model of the gear immediately appeared on the screen. The tooth profile was clear and smooth, and the tolerance of each tooth was marked between 0.006 and 0.009 millimeters, far exceeding the task requirement of 0.01 millimeters.

"We did it! We did it!" Sha Zhu jumped up excitedly and hugged Liu Guangtian tightly. Qin Huairu looked at the data on the screen, tears streaming down her face. This was not only a technological breakthrough, but also a transformation in her life—from a "pseudo-virtuous daughter-in-law" who made a living by scheming, to a technician who established herself on her skills.

Lin Chen picked up the finished gear and examined it carefully under the light. The surface of the gear was as smooth as a mirror, the transition arc at the root of the tooth was smooth and natural, and the traces left by the guide ribs were perfectly integrated into the tooth structure, as if it were a natural creation. He knew that the success of this forging die not only solved the immediate problem, but also created a new forging process. In the future, when encountering similar high-precision parts processing, he would no longer be subject to others.

The next morning, when the first batch of fifty high-precision gears were neatly arranged on the desks of the technical department, the entire department erupted in excitement. The head of the technical department repeatedly measured them with the testing equipment, his expression shifting from doubt to astonishment, and finally to heartfelt praise: "Lin Chen, that kid, is truly a technical genius! Even imported equipment might not be able to achieve this level of tolerance precision!"

The factory director also came to inspect the factory in person. After seeing the gears and the detailed process report, he immediately decided: "This segmented forging die process should be promoted throughout the factory! Comrade Lin Chen, I appoint you as the leader of the factory's technical innovation team, specifically responsible for the research and development of new technologies. Your salary will be directly increased to the level of an eighth-grade worker!"

The news reached the courtyard house, even more exciting than the previous commendation. Liu Haizhong specially killed a chicken, stewed a large pot of chicken soup, and insisted on dragging Lin Chen and Sha Zhu to his house for drinks. "I knew you'd amount to something! I wasn't wrong about you!" Liu Haizhong held his wine glass, his face flushed red. "Following you is a hundred times better than following me!"

Qin Huairu also brought Jia Dang to Lin Chen's house, presenting him with a pair of handmade cloth shoes. "Master Lin, thank you for giving me this opportunity. I made these shoes overnight, and the soles have three layers of stitching, making them very comfortable," Jia Dang said cheerfully. "Uncle Lin, I want to learn a skill too, to be as good as you!"

At Yi Zhonghai's house, however, there was a deathly silence. Mrs. Yi, watching her husband lock himself in his room and not come out all day, could only sigh as she cleared the table of food. Inside, Yi Zhonghai looked at the "Technical Authority" certificate hanging on the wall and suddenly found it particularly jarring. He picked up the forging die drawings on the table; the segmented structure and the design of the guide ribs—every detail exuded ingenuity—forced him to admit that he had truly grown old and had lost.

Late at night, Lin Chen returned to the lab, looked at the successfully completed segmented forging die, and opened the system panel. A new notification appeared on the screen: "Host has developed a segmented high-precision forging die, breaking through technical bottlenecks and completing the 'Process Innovation' achievement. Reward: 5000 points. 'Advanced Material Fusion' function unlocked." Lin Chen smiled and closed the panel.