...

"That's right." Master Duan took a sip of wine with the braised beef and continued: "A sword is divided into nine parts: sword pier, sword hilt, sword eye, sword grid, sword thigh, sword spine, sword blade, sword edge, sword edge. This does not include the scabbard composed of four parts: sheath mouth, sheath body, guard ring, sword mark. Therefore, it is said that making swords is an extremely complicated process and an extremely profound craft."

Ou Chuyang listened very seriously and wrote down every word Master Duan said.

"And, to cast a good sword, it is necessary to go through dozens of processes such as material selection, material refining, hot forging, ventilation, annealing, normalizing, quenching, back-tempering, cold forging, shaping, cutting edge, polishing, polishing, light cultivation, consecration, inlay, seal carving, etc."

Ou Chuyang was shocked. He used to hear that the craftsmanship of the RB knife was very complicated, but after Master Duan said that compared to the sword-casting method in this world, the RB knife was probably just a decorative toy. No wonder Mo Wanqing's Mingshuang sword was so tough, sharp, and so expensive...

"A sword-casting master's energy is always limited." Master Duan talked about the most important thing for Ou Chuyang, "so, a branch was gradually subdivided into the ranks of sword-casting masters: smelters."

"As the name suggests, the smelter must be to assist the sword-caster in completing the steps of selecting materials, qualifying materials, and refining materials, and help the sword-caster prepare the sword-caster's helper for the sword-casting materials." Ou Chuyang guessed.

"That's right." Master Duan nodded in approval, "Originally, the smelters all existed as vassals of the sword-casting masters. But later they gradually became independent and formed their own sects."

"Is this possible?" Ou Chuyang asked strangely.

"Don't underestimate the smelter." Master Duan smiled and said, "The more precious the treasures are, the more difficult it is to refine them into sword-casting materials. They require extremely strict conditions and high-level skills. So if a smelter can be promoted to smelter master or even smelter master, then his reputation and status are no less than that of sword-casting master and sword-casting master. Because only they can refine high-level materials, sword-casting masters can also cast high-level swords."

"So that's it. I really have a specialty in my profession and have the top scorer in every industry." Ou Chuyang nodded frequently and finally saw a glimmer of hope.

"It can be said that if the sword sect in the world has not been opened, if you want to get rid of the tragic fate of becoming a slave, you can only have a smelter. There is no other way to smelter." Master Duan asked Surong, "Would you like to worship me as your teacher and study the smelter method?"

"Master is here, please accept three bows from your disciples!" Ou Chuyang immediately knelt down and gave the honor to his master.

...

In this way, Ou Chuyang officially became a smelting apprentice under Master Duan's sect and was also his only disciple.

"The most common sword casting materials are gold, silver, copper, iron, and steel. The gold, silver and copper are too soft. Except for a few special varieties, most of them are used in scabbard thighs and other places. Therefore, the most commonly used sword casting materials are two major categories: iron and steel. Of course, it is not uncommon for swords made of special materials such as jade, stone, wood, and ice. But you can't get in touch at the moment, so don't use it."

"Yes, Master." Ou Chuyang listened very seriously, and Master Duan taught very carefully.

"The first step is to learn cast iron first." Master Duan took Ou Chuyang to the front of a melting pot and continued: "Cat iron is fragile and can be cast but not forged. Therefore, all swords are made of cooked iron. Crafted iron is refined from pig iron, also known as wrought iron, pure iron."

...

Wash sand: peel off the iron sand from the ore ore.

Smelting: Place iron sand and toner layer by layer in the furnace, and smelting at high temperature to obtain iron.

Refining: further remove impurities and make iron purer.

Through these three steps, we have become the most primitive first-level sword material: cast iron.

Master Duan picked up a piece of cast iron and pointed it at it. There was a faint flow of sword energy. After checking it, he nodded and said, "Well, the purity is good."

"Master, are you sword energy?" Ou Chuyang asked.

"Yes, this is the sword energy material. The sword caster injects the sword energy into the sword material to test the purity and characteristics of the material." Master Duan asked again: "Casted iron has been more than a month, do you have any experience?"

"It's not a question of experience." Ou Chuyang seized the opportunity and communicated with his master. "I just felt that for the smelter, the most important thing is to control the temperature. It is necessary to know how high the temperature should be used for smelting; the second is the mixing ratio of raw materials and fuel, and know how to remove impurities without adding other impurities."

"Yes, my head is pretty good." Master Duan nodded in approval, and then said: "However, this is just the foundation. Every successful and famous smelter has three treasures."

"Three** treasures?"

Master Duan explained in detail to Ou Chuyang: "The first is fire: There are many strange heavenly fire, earthly fire, and fire outside the sky in this world... All kinds of strange flames are collectively called strange fire. The stronger the strange fire, the higher the level of sword-casting materials can be melted. So for high-level smelters: strange fire is their life root!"

"Sky Fire, Earth Fire, Fire outside the sky... Strange Fire..." Ou Chuyang's eyes lit up, illuminating a bright road.

"The coal fire used for steelmaking is just the lowest level of ordinary fire, and it is not considered strange fire. It cannot meet the requirements of high-level smelters. Some of them extract lava fire essence from the center of the earth, and some even absorb fire from meteorites outside the sky, and various sects perform their own abilities. The strange fire in their hands basically determines the future of the smelter's level." Master Duan patted Ou Chuyang on the shoulder, "What kind of height can be reached depends on your luck."

Does temperature determine the altitude? Ou Chuyang remembered the knowledge he had learned before: the household gas stove can reach 1800°C; the oxygen acetic flame used by the welder can reach 3000°C as the same as the volcanic eruption; and the temperature of the vacuum arc furnace is close to the surface of the sun, reaching a terrifying 6000°C... Unfortunately, the scientific knowledge in my head cannot be applied in this world, otherwise it would be easier to become a high-level smelter?

"In addition to the strange fire, the second secret of the advanced smelter is the refining method you mentioned." Master Duan continued: "There are different temperatures required for purifying the sword-casting materials, and the techniques used are also different. These are the secrets of each smelter, and they are also secrets that are not passed on."

Only then did Ou Chuyang realize that he still regarded the smelter as too simple. It was not just that he could use high-temperature smelting materials, but also a technical job...

"In addition to having strange fire and secret techniques, every high-level smelter also needs a treasure."

"baby?"

"That's it." Master Duan smiled and pointed at the smelting of iron.

"This..." Ou Chuyang was a little confused.

"Do you think this clay-fired furnace can last for a lifetime?" Master Duan smiled and said, "There is earth fire above the earth fire, the heavenly fire above the heavenly fire, and the sky fire above the heavenly fire, and the supreme holy fire... Not to mention the existence of the holy fire as illusory as the holy fire, just say the heavenly fire, its terrifying power burns the sky and destroys the earth. This clay melting furnace is afraid that it will turn into nothingness in an instant under the heavenly fire."

"Hiss--" Ou Chuyang took a deep breath. There was such a terrifying flame in this world? Can the temperature exceed the surface of the sun and instantly vaporize the clay melting furnace? This is simply unscientific...

"So, after the smelter is obtained, he must have a furnace that can store flames before he can be used to smel the sword material." Master Duan stretched out three fingers, "Flame, secret method, the furnace is the three treasures of the smelter. It is with these three treasures that the smelter gradually separated from the ranks of the sword-casting masters, forming a series of their own, and finally achieving an extraordinary position of equality with the sword-casting masters."

"Thank you for your advice, please keep it in mind." Ou Chuyang said solemnly: "I will definitely not disappoint my master."
Chapter completed!