"How could you ......"

Liu Sheng Huimei's face was full of horror, staring at Su Yuan with her small mouth open, dumbfounded, if she wasn't sure that today was the first time she met, she would definitely think that the other party had witnessed the whole process of casting her sword with her own eyes!

"There are many problems with your knife craftsmanship, first of all, jade steel, although the price of the red eye iron ore is selected, the iron sand will sink to the bottom of the fire bed within an hour when smelting, and the swordsmith must see whether the iron sand has turned into jade steel from the color of the fire bed. It is also important to ensure that the pig iron does not dissolve, which gives the katana its indispensable chemical and physical properties. ”

"Then the iron ore slowly melts into the furnace, and there is a combustion chamber three meters deep under the furnace, and when the temperature reaches 1,000 degrees Celsius, all the impurities sink to the bottom of the combustion chamber, leaving only pure steel. ”

"A master must practice listening to the sound of the furnace to judge the progress, and a good knife must be wrapped in high-purity steel on the outside, and there will be a small amount of impurities inside, such as sulfur, so that the blade will be sharp. ”

"Because of your lack of experience, you didn't grasp it well, resulting in insufficient purity of jade steel!"

After hearing this, Emi Yanagi's face changed greatly, and just as she wanted to speak, Su Yuan interrupted directly and continued: "The second problem is more serious, which is forging. Reheat the jade steel to 1300 degrees Celsius, and then beat all the steel pieces into one piece while the heat has not dissipated, requiring fast action and precise force, so that the forging can remove the remaining impurities. ”

"To reduce the quantity of the finished product by half compared to the original pig iron to become a whole knife blank, it is necessary to continuously fold and forge the steel block to evenly distribute the carbon, so that the metal raw material of the cast knife is completed. ”

"And as a woman, your strength is obviously insufficient, and you haven't let others help, resulting in the density of the knife embryo is far from the standard, and the outside is strong and the middle is dry!"

Su Yuan pointed to the pattern on the sword, and scolded: "The best proof is here, the real master will estimate the carbon content according to the color of the steel, after continuous folding and forging, there are more than 5,000 layers of steel per centimeter, and the texture formed is called the earth muscle, just like the Longquan sword, the clearer the better, not chaotic." ”

"You still use the ancient method of mud quenching for this knife, right?" Su Yuan looked at Yagyu Emi's increasingly surprised expression, shook his head and said: "Mud quenching is an ancient method that has been passed down for thousands of years, and it can be evenly applied to the knife surface to isolate and protect all important parts of the blade during the hardening process, and there will be an obvious line at the intersection of the softer steel and the hard blade inside, which is actually the blade pattern, which is an important symbol of the high-grade katana." ”

"Then the fire refining is carried out, and it is required to accurately judge the temperature of the blade by the eyes in the dark, and 800 degrees is the best, that is, when the blade reaches the bright red of the morning sun. ”

"When you put the blade in water where it has reached a temperature, the part covered with thin clay will cool down rapidly and become very hard, and the edge of the clay will cool down quickly, and the carbon in the steel will become the edge of the knife when it cools quickly. ”

"The structural changes during the cooling process cause the katana to bend naturally, and a high-grade katana is curved in the shape of a crescent moon, like a tengu eating the moon. ”

Emi Yanagi has nothing to say now, looking at her peers in front of her blankly, Su Yuan put down the knife and said helplessly: "The only thing worth affirming is the grinding process, I can only say that you have money, and you don't hesitate to spend thousands of dollars on the stone, although the technique is rough, but the effect is quite passable." ”

"It's a pity that I still don't understand the essence of grinding, and when sharpening the sword, the master has to carefully look for the beauty of the connotation of each katana, as well as the subtlety of each swordsmith's school when casting the knife, and teaching it according to the aptitude is perfect. ”

"Not to mention the fine grinding, but also the overall grinding......"

"What?" "Emi Yanagi suddenly exclaimed, grabbed Su Yuan's arm tightly, and asked, "You actually know how to grind as a whole?"

"Hmph, what's so difficult about this!" Su Yuan snorted coldly and said confidently: "Longquan is the thousand-year-old sword forging capital, and there are many ancient secret techniques, so how can I worry about grinding as a whole!"

Looking at Huimei's sluggish expression, Su Yuan's heart was secretly refreshed, in fact, the overall grinding method was very mysterious, and it belonged to a secret that was not passed on. It is probably necessary to use a unique method to whiten the blade to expose the line where the soft and hard steel meet, so as to achieve the result of gradually revealing the inner beauty of the metal.

Then there is sharpening the tip of the knife, in the same way as sharpening the blade, but with more care and focus. Each has its own unique recipe for sharpening the tip of the knife, so the final result is also different.

This is also why Dibang wants to use the method of dropping silk scarves to test the sword, and even a master like Xu Kui is not perfect in handling the tip of the knife, which shows how difficult it is.

"You...... I ......"

Emi Yanagi was stunned, looking at the originally confident sword in her hand, she suddenly gritted her teeth, raised her head, and retorted loudly: "Words have no basis, and words on paper can't prove everything you say, so ......"

"Do you want evidence?" Su Yuan waited for this sentence, smiled slightly, picked up the sword again, turned around and came to the display table, and fixed it on the iron frame.

"I'll prove it to you now!"

Su Yuan turned around, his sharp eyes locked on Emi Yanagi, stretched out his hand, and said to Xu Kui: "Broken sword!"

Xu Kui took out the broken sword from the package, offered it with both hands, Su Yuan held the sword in one hand, and said, "Do you want to see the evidence?" Just your knife, not to mention the seven-star sword, even a broken sword can be cut and broken. ”

"Look!"

After speaking, he turned around sharply, slashed hard at a certain position of the knife, only heard a crisp impact, and everyone was instantly stunned.

"One sword and two cuts!"

"Wouldn't it?

"That's too watery, isn't it?"

Emi Yanagi's eyes were dull, looking at her proud work on the ground, she was split in two casually, and the other party was still a broken sword!

Su Yuan returned the broken sword to Xu Kui, and stood with his hands in his hands, the little girl in front of him was hit hard, and he felt a little sorry in his heart. It seems to be a broken sword, but it is actually a golden light sword that is like a fake, not to mention that he is still the most vulnerable sword heart, so he will naturally be able to catch it.

Who made Emi Yagyu unlucky, was selected by the system, and if she wants to conquer the little girl's skin as soon as possible, she must be hard and big, big, live well, and not sticky!

"Actually, your qualifications are okay, but you lack the guidance of famous teachers, and many things can be done without money, I hope you can understand this. ”

Facts speak louder than words, and if you had just heard someone say such a thing, you would have dismissed it. But now, Emi Yanagi looked at Su Yuan and finally understood why even Jin Sanye treated this young man respectfully.

Suddenly remembering something, he turned around sharply, quickly took out another sword box from the box, came to Su Yuan, bowed deeply, raised his hands above his head, and said respectfully: "Thank you Master for your guidance, please take a look at this knife again!"