Studying at Western University starts with a knife-forging competition

The annealing was completed around noon. Lin Yuan took the sword blank out of the lime; the blade was straight, without any bending or twisting. He used calipers to measure the thickness at the root, middle section, and tip, and the data matched the target he had marked in his notebook perfectly.

Quenching is the most crucial step in crafting the Paladin's Cross. The quenching temperature range for the Paladin's Cross is narrower than that for regular high-carbon steel, and the blade is much longer than that of a dagger, multiplying the difficulty of controlling the cooling process evenly.

If it warps or cracks, the forging of the previous two days is completely wasted.

The first day's practice sword blank has verified the basic quenching process of the hand-and-a-half sword. However, this sword contains holy silver, and silver has a higher thermal conductivity than steel. The cooling rate of the silver-containing area and the non-silver-containing area is different. The oil entry angle must be recalculated to equalize the cooling rates on both sides. Otherwise, thermal stress will concentrate at the silver-steel interface, which will be the starting point of the crack.

The workshop was quiet. The three members of the film crew remained in their positions. Mark had finished his energy drink and was clutching the empty bottle between his fingers, forgetting to throw it away.

Lin Yuan placed the sword blank into the forge and stood in front of it. The sensation of the molten metal spreading along the temperature field of the flames, he noticed that the heating rate of the holy silver area was slightly different from that of the pure steel area. He waited a few seconds to allow the heat to catch up.

When the temperature of the entire sword blank is uniformly within the target quenching range, he uses tongs to clamp the sword blank out.

Pre-cooling. The sword blank remains in the air, and the surface temperature drops slightly from its peak, with heat being evenly conducted from the center of the blade to the surface. With the experience of practicing on the sword blank yesterday, and with the aid of his perception from the layered fire forging, he can clearly judge when the isotherm stops at the center.

He walked towards the quenching tank, where the sword blank and the oil were precisely positioned for oil insertion.

The quenching oil emitted a short hiss the moment it came into contact with the scorching sword blank, and oil mist surged up from the groove. He controlled the arc and speed of the oil injection, executing every parameter according to the data calculated the night before.

The entire quenching process didn't last long, but the air in the workshop almost stagnated during that time. After the hissing sound of oil subsided, Lin Yuan took the sword blank out of the quenching tank.

The surface of the sword blank was covered with a layer of dark gray oil film. He scanned the interior with his internal vision and found that the martensitic transformation was progressing evenly. The cooling rate of the holy silver region and the stress difference between the pure steel region were leveled out by the fine adjustment of the oil injection angle.

No cracks, no warping. The breath he had been holding in since he entered the workshop at eight in the morning was finally exhaled in a long, deep breath.

Tempering followed immediately. He placed the sword blank into the tempering furnace and, while waiting, used calipers to recheck the straightness of the blade—there was no bending from the base to the tip, no warping in the middle of the edge, and the back of the blade was as straight as ever. After tempering, he cooled the sword blank to room temperature in the air and then clamped it in front of a belt sander to begin rough grinding.

The rough grinding starts at 400 grit and proceeds step by step, with each section being cooled by immersion in water to prevent localized annealing of the cutting edge due to high grinding temperatures. There are no bluish-purple grinding burn marks on the cutting surface, only a silky sheen as the metal gradually becomes finer under the abrasive belt.

After the rough grinding was completed, he rinsed the blade with clean water and dried it. The sword blank was fully revealed under the workshop lights—the blade was long and straight, the blood groove extended from the root to the middle section, the double edges were symmetrical, and the edge lines were clean.

The thickness transition curve narrows evenly from the root to the tip of the sword, which is exactly the same as the structure of the practice sword blank from yesterday.

However, unlike the practice sword blank, this sword has a very faint golden sheen on its blade.

It wasn't a pattern, nor an etched design, but light—the faint golden halo emanating from the silver material incorporated into the sword blank under light.

The effect is still very subtle and needs further refinement to be fully realized, but the basic effect is already visible.

The golden hue emanated from within the sword, without a clear boundary, flowing as the viewing angle changed.

Mark stood up from the corner, still clutching the empty drink bottle, took a step forward, and was stopped by the cameraman.

He forgot that the cameraman was still behind him.

The cameraman moved the lens away from behind Mark and refocused it on the sword blank in Lin Yuan's hand, slowly rotating his finger on the zoom ring to bring the image to a close-up of the blade.

In the viewfinder, the golden halo flowed quietly under the fluorescent light.

Lin Yuan placed the sword blank on the worktable and covered it with a cotton cloth.

He turned to face the camera, his voice tinged with a relaxed weariness: "This morning we did the normalizing and annealing, and this afternoon we did the quenching, tempering, and rough grinding. All the key steps are done today. The final effect will be fully achieved after the fine grinding. We'll make the sword fittings tomorrow."

Mark finally threw the empty drink bottle into the trash can: "This sword is completely different from the little dagger you had in the first round."

"Yes. That dagger was forged using a folding forging technique, creating a layered pattern by stacking different types of steel." Lin Yuan wiped the remaining oil from his fingers with a rag, his tone natural. "This sword is different. The silver was hammered in along with the steel billet during forging, which creates this flowing effect on the surface of the blade. This is a technique passed down in my family."

Mark quickly jotted down a few notes on the whiteboard, then looked up and glanced again at the unfinished sword covered with a cotton cloth on the workbench.

On the morning of the third day, when Mark walked into the workshop, the cameraman had already set up his camera directly in front of Lin Yuan's workstation, with the viewfinder pointed at the sword blank covered with cotton cloth on the worktable.

Mark went over and confirmed one thing—the cotton cloth was still covering the sword blank, and no one had touched it.

Lin Yuan pushed open the door and came in, placing his backpack on the workbench and removing the cotton cloth. After cooling overnight, the golden aura of the sword blank was fainter than yesterday, and the internal structure of the material had become more stable after quenching and tempering.

He put on his earmuffs, sat down in front of the belt sander, and started grinding from 1200 grit upwards. After each section, he ran his fingertips over the blade to check for flatness, and after each section was finished, he soaked it in water to cool it down.

When the blade reached 1500 grit, the golden aura on its surface began to change. It was no longer the faint, almost imperceptible gold of a rough-polished blade, but rather a gradual brightening as the roughness of the blade surface decreased. By 1800 grit, the gold was clearly visible.

When the blade reaches two thousand marks, the luster of the silver shines through the inside of the blade, merging with the silky sheen of the outermost layer of the blade surface to create a warm and profound golden luster—as the light moves across the blade surface, the gold also moves with the light, flowing slowly as the viewing angle changes.

The cameraman's finger slowly rotated the zoom ring, zooming in from a mid-ground view of the sword to a close-up of the blade. Within the viewfinder, the gold color gradually faded from the center of the sword outwards, with no clear boundary at the edges.

The sound engineer removed his headphones and straightened up. Mark stood up from his folding chair, walked to Lin Yuan's side, and looked down at the sword's flowing gold under the light. He thought for a moment, then asked softly, "Is this the effect of the silver you initially inserted?"

"Yes." Lin Yuan also looked at the halo on the sword. It was the first time he had seen the complete effect after fine polishing.

The effect achieved with the gold coins spent was worth it.

He picked up a cotton cloth and repaired a tiny mark on the sword that hadn't been wiped clean yet.

Mark made a note on the writing board.

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Meanwhile, in a tin shed outside Birmingham, Alabama, Greg felt something was wrong as he took the sword blank out of the quenching tube.

The oxide scale on the blade surface peeled off evenly, but the sound of the oil churning during quenching was more muffled than usual, and the steam dissipated more slowly. He held the sword blank up to the light and flipped it over. There were no obvious warping or cracks, but when he gently scraped the blade with his fingernail, that familiar crispness and hardness was not there.

He stood silently in front of the quenching cylinder for a while, wondering if he had made a mistake in one of the steps. The heating temperature was correct, and the color appeared the same as usual. The pre-cooling time was also precise. The oil filling technique had been measured repeatedly, and the tilt angle was very stable. Every step of the process had been checked repeatedly; theoretically, there shouldn't have been a problem.

He decided to quench it again.

He reheated, pre-cooled, and re-oiled the blade. This time, he deliberately extended the time it spent in the oil. After taking the blade out, he waited a moment for it to cool to room temperature, and then scraped the edge with his fingernail—it was still too soft.

The second quenching did not solve the problem.

He placed the sword blank on the workbench and squatted down to inspect the oil in the quenching barrel. The oil was a shade darker than he remembered, and a slight rancid smell could be detected when he got close. He had used this barrel of oil for several years, only adding new oil twice, and had never completely changed it.

When making short knives and hunting knives, the quenching window is wide, and the impact of oil aging on the cooling rate is within an acceptable range.

However, the uniformity of the cooling rate is much higher for hand-held swords than for short swords, and the cooling curve of the old oil has become skewed.

He squatted in front of the quenching cylinder, stunned for a few seconds.

Then he stood up, took off his apron and draped it over the tool cabinet, and picked up his car keys and wallet.

It was already night outside the tin shed. There were no streetlights on the rural roads of Alabama. His old Ford pickup truck, with its two headlights on, drove over the gravel road toward town.

He had to hurry and get to the town's suppliers before they closed, or he would have to wait until tomorrow morning.