Studying at Western University starts with a knife-forging competition

After normalizing, he reheated the billet and then removed it to begin annealing. The difference between annealing and normalizing lies in the cooling rate—normalizing involves cooling in air, while annealing requires wrapping the billet in insulating material to allow it to cool slowly, softening the steel as much as possible for easier cutting and grinding later. This step seems simple, but if the annealing temperature is not well controlled and the cooling rate is uneven, new stresses will remain inside the material, causing the billet to deform during subsequent quenching.

He took the annealed billet out to check the amount of deformation, then made corrections, and then put it back into the furnace to reheat it to a dark red color, before covering it with dry lime.

After completing this step, he straightened up and wiped the sweat from his forehead with his sleeve. Annealing takes several hours to complete, and the billet needs to be slowly cooled to room temperature in dry lime. In the meantime, he can do some other basic skills practice.

Lin Yuan walked to the tool wall and took down the 1095 hunting knife Robert made in the 1990s. He examined it several times, turning it over and over. He knew every detail of the knife so well that he could draw it with his eyes closed, but each time he looked at it again, he discovered something new—the technique used to finish the blade, the angle of the clean cut, the perfectly fitting joint between the guard and the handle. Good things stand the test of time.

He hung the knife back up and returned to the forge.

At 11:15, footsteps were heard at the door.

When Robert pushed open the door, he still had the folder in his hand. The collar of his work shirt was still undone at the top two buttons. His eyes, behind his silver-rimmed glasses, swept across the workshop, lingered on Lin Yuan in front of the furnace, and then glanced at the several pieces of forged blanks placed next to the anvil.

He placed the folder on the shelf by the door, said nothing, walked over, picked up a piece of blank material, and examined it. The surface of the blank material already had a preliminary outline of a blade, the forging marks were even and clean, and the curves of the edges were smooth.

Then he picked up the second piece.

The third piece.

Robert's brow twitched. He put the billet down, picked up the first one again, and examined it once more, his fingers slowly tracing the forging marks on the surface of the billet.

"Did you make all this today?"

"Forged this morning." Lin Yuan picked up the fourth billet from the furnace and placed it on the anvil. Before the hammer fell, he added, "The normalizing and annealing are not finished yet."

Robert didn't ask any further questions. He put the blank back in its place, walked to the old chair against the wall, sat down, took out the pack of chewing gum from his pocket, pulled out a piece, slowly unwrapped the foil, and put it in his mouth.

He just watched Lin Yuan hammer for a full twenty minutes.

Robert didn't speak until Lin Yuan buried the last piece of raw material in the pile of dry lime.

"You passed the preliminary rounds?"

Lin Yuan turned around.

"It's approved. I received the email last night."

Robert nodded, pausing his chewing of gum.

"Today is different from before," he said.

It's not a question.

"I'm trying out some new things. I want to connect a few things together." Lin Yuan thought for a moment. He didn't know how to explain the system to Robert, so he could only choose a more general explanation.

Robert leaned back in his chair, his hands clasped in front of his abdomen.

"You know I've been in this industry for thirty years and have seen the work of many people," he said. "A good knife maker's work is so distinctive that you can tell at a glance. The force, the angle, the heat—every choice is reflected in the piece."

He paused, took off his glasses, and wiped the lenses with the hem of his shirt.

"Your previous works were already very good, with your own style and solid fundamentals." He put his glasses back on. "But these things today—using the same techniques—are completely different from before."

Lin Yuan didn't speak, but looking at the elderly professor with graying temples, a warm feeling welled up in his heart. He understood that Robert was telling the truth, not just an elder encouraging a younger person. He had felt it himself while forging the iron earlier; that sense of certainty, that sense of control, was indeed on a different level than before. He just couldn't explain it clearly himself, but Robert had made it clear for him.

"I don't mean to be immodest," Lin Yuan said softly, "but I did sense something I hadn't felt before."

Robert looked at him for two seconds, and the corner of his mouth twitched. It wasn't a smile, but an expression somewhere between satisfaction and approval.

"Prepare well for the competition."

"I will prepare well."

In the afternoon, Lin Yuan didn't start anything new. After annealing, he took out several blanks and cleaned them, removing the oxide scale produced during calcination and cutting off any unnecessary parts for later processing. Then he welded a box out of thin steel plates, filled it with coarse sand, and heated it with a gas torch.

He was performing spheroidizing annealing on the billet. This was a process he had developed and figured out himself. By heating the billet to near the eutectoid temperature and then holding it at that temperature for a long time, the carbides inside the steel were transformed from lamellar to spherical.

This step is to give the steel better machinability and hardenability—the internal stress of steel treated with spheroidizing annealing is more uniform, the deformation during quenching is smaller, and the hardness distribution is more uniform.

This wasn't a skill his father taught him. The old blacksmiths in Longquan don't do spheroidizing annealing; they rely on experience to judge the heat and tempering temperature, using skills passed down from generation to generation.

It's not something taught in university classrooms. Materials science courses will cover the spheroidization mechanism of cementite and the eutectoid transformation temperature range, but undergraduate lab courses only cover basic metal processing and heat treatment. More advanced processes like spheroidizing annealing are usually covered at the graduate level, and even then, it's mostly theoretical discussion rather than hands-on practice.

This is his third path—to combine the theories he learned in university with the skills passed down from his father, and then use systematic skill tempering to give it a push, so that the three can truly merge.

The sand temperature is controlled at 1200 degrees Celsius, and after holding at that temperature for four hours, it is cooled with the furnace. University textbooks provide complete data and charts on the temperature range control, heating rate, and holding time for this process, but they won't teach you how to achieve these precise controls in a forging furnace using just a pair of tongs. But the skills his father taught him allowed him to—judging the furnace temperature visually and assessing by touch whether the heat had evenly penetrated every inch of the steel billet surface.

The system's tempering spirit adds the most subtle layer of control. By activating the internal network of the metal through tempering spirit, he can sense that the changes in the internal structure of the steel tend to be more uniform and stable.

After spheroidizing annealing, he ground and pickled one of the billets and inspected its cross-section. Then he placed the treated billet in an insulated oven to cool it down slowly.