Major Heavy Industry: Starting with a Fake Marriage

Chapter 112 is really boring.

Jiang Cheng took it and rubbed it back and forth with his fingertips. Indeed, the coating surface was not smooth enough; he could feel tiny bumps, like fine sandpaper.

He looked at the spraying parameters and then at the test piece.

"The powder feeding rate is too high? The powder is not melting sufficiently."

"Possibly. Let's try reducing it to six grams."

The second coat was applied. The powder feed rate was adjusted to six grams. The spray gun was ignited again, the flame shooting out and the powder being fed in. This time, Jiang Cheng adjusted the speed of the spray gun's movement, allowing the flame to remain on the test piece surface for a longer time. After about ten seconds, the test piece was removed. This time the surface was smoother, like a thin layer of glaze, and it felt slippery to the touch. But when Jiang Cheng pressed his finger, he felt an air bubble between the coating and the substrate—the coating bulged up into a small bump, like a blister on the skin. When pressed, it burst, revealing the underlying metal substrate. On the silvery-white substrate, there was a dark ring, as if it had been burned.

"Poor integration." Chief Engineer Chen's voice was calm, but Jiang Cheng could hear the disappointment beneath it. That disappointment wasn't directed at him, but at the outcome.

She picked up the sample and examined the tear against the light. "Is the gas flow rate too high? The powder didn't stay in the flame long enough to completely melt. When it hit the substrate surface, it was still solid, resulting in a weak bond."

Jiang Cheng nodded. He looked at Huang Deqing, who walked over from the corner, picked up the test film, examined it against the light, and then touched the bursting point of the bubble with his finger. His fingers were short and thick, with black dirt embedded in his fingernails, but his movements were very light, as if he were touching something fragile.

"It's not a problem with the gas flow rate," Huang Deqing said, his voice low but thunderous. "The root cause is that the substrate wasn't cleaned properly. Look at the edge of this tear; there's a ring of black stuff—that's oil. If there's oil on the substrate, the coating won't stick. The oil will vaporize at high temperatures, the gas will expand, pushing the coating up and causing it to bubble."

Chief Engineer Chen paused for a moment, took the test piece, and examined it closely. She held the test piece up to the light, squinting for several seconds. Sure enough, there was a faint dark ring around the edge of the tear, barely noticeable unless you looked closely, like a line lightly drawn with a pencil.

"Who did the cleaning?" she asked, her voice slightly louder than usual.

The technician next to him raised his hand. He was a young man in his early twenties, wearing thick glasses, with a round face, and he looked a little nervous. "I did it. I washed it with acetone, three times. The acetone was fresh, just taken from the reagent cabinet."

"There's still oil after washing it three times?"

The technician came over and looked at it, his face changing from white to red, then back to white. "It's probably oil from the gloves. The gloves I was wearing weren't new; I'd touched other parts before. I touched... a bearing, a bearing coated with anti-rust oil. I forgot to change my gloves."

Chief Engineer Chen remained silent for a moment. The laboratory was quiet, save for the hum of the ventilation ducts. Then she turned to look at Huang Deqing. There was something in her gaze—not surprise, not admiration, but a scrutinizing look, along with a hint of amusement.

"Master Huang, you have a good eye."

Huang Deqing didn't speak, retreating to the corner. He put his hands in his pockets, standing there like an old tree, motionless and silent, but you knew he was deeply embedded.

The third coat was applied. The technician changed into new gloves, brand new, white, and still covered in talcum powder, which he had just unpacked. The substrate was cleaned again with acetone, five times, each time wiped with a new cotton ball soaked in alcohol, rinsed with deionized water, and finally dried with compressed air.

The compressed air flow was very strong, blowing against the substrate and making a hissing sound, like a snake flicking its tongue.

The spraying parameters were restored to their initial values: powder feed rate of 8 grams and spraying distance of 120 millimeters. The spray gun was ignited, the flame shot out, and the powder was fed in. This time, the coating surface was smooth, without bubbles or graininess, like a gray mirror. I touched it with my finger; it felt uniform, like touching a pebble that had been washed and polished by a river over time.

Chief Engineer Chen examined the cross-section under a microscope. Through the eyepiece, the coating's cross-section revealed a layered structure: a grayish-white ceramic layer, a dark gray transition layer, and a bright white metal substrate, all clearly defined and seamless. She straightened up, took off her glasses, and wiped the lenses.

"This layer is acceptable. But this is just a flat sample, not a blade. Real blades have complex shapes, with air film pores and curved surfaces. We don't know if we can guarantee uniformity during spraying."

Jiang Cheng nodded. He knew this was only the first step.

Three coats of paint were applied that morning, and all three had problems. The first coat was rough, the second had poor adhesion, and the third was barely acceptable. Chief Engineer Chen kept recording the data, writing down every parameter clearly, including the units for each number. Her expression remained serious; she would occasionally furrow her brow or nod, but never smiled. Her lips were always pressed together, like a thin slit.

At lunchtime, Sun Deming sat down next to Jiang Cheng with his rice bowl. The canteen's dish was stir-fried cabbage with sliced ​​pork. The cabbage was cut too coarsely, some pieces large, some small, uneven. The pork slices were cut too thin, shrinking into small pieces after stir-frying, hidden among the cabbage leaves, requiring a lot of searching with chopsticks to find. There wasn't much oil, making it bland and tasteless, like chewing cardboard. Sun Deming ate a couple of mouthfuls of rice and looked up.

"Brother Jiang, how many times do you think we'll need to do this experiment to succeed?"

"have no idea."

"Chief Engineer Chen said GE has been working on it for three years and still hasn't succeeded. We only have a few people and a few pieces of equipment, can we really do it?"

Jiang Cheng put down his chopsticks and looked at him. Sun Deming's face showed an expression that wasn't fear, but confusion, like a lost person standing at a crossroads, not knowing which way to go.

"Deming, are you scared?"

Sun Deming shook his head. "It's not that I'm afraid. It's that I'm not confident. When I repaired machines before, I could tell what was wrong just by taking them apart, and I could replace the broken parts with the good ones and screw them back on to make them turn. This coating, you can't see it or touch it. Whether it's good or not depends entirely on the microscope and the data. I'm not confident. It's not that I'm afraid I can't do it, it's that I don't know if I can even do it."

Jiang Cheng was silent for a moment. He knew Sun Deming was right. Before, repairing machines was a "mechanical problem," something tangible and visible. A broken bearing was simply broken; replacing it would make it run again. Now, it was a "materials problem," invisible to the naked eye, relying on data and experience. These were two completely different fields. One was black and white, the other gray.

"That's right, it's because we're uncertain," Jiang Cheng said. "Anyone can do things that are certain. It's the uncertain things that require our expertise."

Sun Deming paused for a moment, then laughed and said, "Brother Jiang, what you're saying is really meaningless."