Chapter 2: Teaching You What Tempering Fire Is

  Quenching is a metalworking process in which the metal workpiece is heated to a certain suitable temperature and then rapidly cooled by immersion in a quenching medium. After forging various iron tools, folk blacksmiths need to quickly immerse the red-hot iron tool into water for cooling, which is one way of quenching.

  Quenching and tempering, annealing, normalizing, etc. are collectively referred to as heat treatment processes, which are an important means of improving material properties. By precisely controlling the medium, temperature, time and other factors in the heat treatment process, the toughness, strength, hardness, wear resistance, fatigue strength and other properties of the material can be made to meet specific requirements, and the learning involved is profound and immeasurable.

  As a materials expert, Qin Hai has an in-depth understanding of heat treatment processes. He just took one look at the farm tools made by the fat men and knew that they had not undergone quenching and tempering. 65 manganese steel is excellent in both toughness and wear resistance, but if it is not properly quenched after processing, the steel will become soft, resulting in the rolled edge phenomenon we see now.

  They were all half-baked apprentices, and when it came to processing techniques, they didn't know much. Even the term "quenching" mentioned by Qin Hai, they couldn't react immediately. The word "quenching" should be pronounced as "cuì" according to the dictionary, but in the heat treatment industry, people are used to pronouncing it as "zhàn", which is derived from the traditional northern folk term "jiàng huǒ".

  "Is it... brittle fire you're talking about?" asked one of the three young men, a short one, tentatively.

  "Hmm, it can be read that way too." Qin Hai compromised, now is not the time to popularize terms, as long as the other party understands what he means.

  "We couldn't find water back then," the short one replied in a barely audible voice. As an apprentice, he had never eaten pork but had seen pigs run, and he had at least seen the process of quenching fire, just didn't know what it was for. When making these farm tools, maybe as he said, because there was no convenient cooling water nearby, so they skipped this step.

  "What? Your ironware hasn't even been quenched and you're selling it, isn't this a fake product!" A few peasants seemed to have grasped the reason, and they all shouted together. Although they didn't understand industry, at least they had seen blacksmiths forging iron and knew that quenching was necessary, and also knew that unquenched ironware wasn't useful.

  "Return goods!"

  "Give me back my money!"

  "Make them pay!"

  Several farmers shouted loudly and waited for Qin Hai to speak out for justice on their behalf.

  "How is it? What do you three think?" Qin Hai looked at the three young people and asked.

  The fat man spoke in a somewhat soft tone, muttering: "They just want to blackmail us, we use good steel... even if it's not tempered, the steel is still good... such good steel, and it's five cents cheaper than the blacksmith's shop..."

  He spoke to himself, but the meaning that came out was very clear, that is, he was not willing to refund the money. The five peasants bought seven or eight pieces of agricultural tools from them, worth more than ten yuan, if they returned all the goods, it's estimated that they really couldn't afford to pay back.

  Qin Hai saw Paozi's dilemma and turned his head back to the farmers, saying: "Everyone, I'd like to propose a plan, is that okay?"

  "Say it," said several farmers.

  "Since you've all purchased farming tools from these brothers, I'm sure they're useful for your households. The steel used in these tools is indeed good quality, it's just that a step was missed during the processing. If you're willing, I'll have these brothers rework the tools and add the quenching process. I guarantee that after repair, the quality of these tools will be better than any you've used before. What do you think?"

  "Hey, do you know what tempering is? We don't understand this." The fatty pulled Qin Hai's collar from behind, afraid that Qin Hai's words would get them all into trouble.

  Qin Hai gave Bao Zi a glare with a gaze that could kill, saying: "Since I dared to promise, I naturally have confidence... however, you guys need to help me find an ironwork shop and some quenching medium, I'll tell you in a bit."

  It took some time, and the few farmers had simply exchanged opinions, probably thinking that entangling with Fatty and others would not have any results, and they indeed needed these farm tools, so they nodded their heads and said to Qin Hai: "In consideration of your young face, as long as they can repair these farm tools well and guarantee no cheating, we will not return the goods."

  "Who dares to guarantee that the blade won't roll?" The tall young man chimed in inappropriately, "You use iron trowels as cleavers to chop brick heads, and they won't roll either?"

  "If the quenching is done well, it can indeed be non-curved." Qin Hai smiled and replied.

  "Alright, just for your sake as a young man, if you say that this iron shovel won't bend after being tempered and can split bricks, I'll buy all the farm tools on this stall!" The leader of the peasants came up with an aggressive tactic. In his heart, he also felt that Qin Hai's words were somewhat exaggerated, but at this time, he supported Qin Hai, which could force those three young men to have no way out. This kind of thing was naturally music to his ears.

  "Did you say that yourself? Alright, buddy, tell me, how do we temper the fire?" The fatty's passion was ignited by that farmer, and he suddenly had a desire, which was to hope that Qin Hai could really process these farm tools to the point where they wouldn't even bend when hitting a brick, so that way, he could use the farmer's words to force him to buy all the remaining tools. This wasn't just about how much money he could make, but also about regaining the face he had just lost.

  Qin Hai looked at both sides, shook his head helplessly, and then said to the three young men: "To make a fire, you first need a furnace... You are all from factories, right? Are you going back to your factory or finding an ironwork shop, what do you say?"

  "Let's find a blacksmith shop." The short guy said. Selling farm tools to make money was their private business, and it was better not to involve the factory in such things.

  "Not far from here is Zhang Lao San's blacksmith shop. I'm familiar with him and can take you there." The leading farmer pointed in a direction and said.

  "That's good." Qin Hai nodded and said to the young people, "There is one more thing that needs you to find. I need to configure some quenching solution, which requires several chemical reagents. These reagents may only be found in a middle school laboratory. Who has connections?"

  "I," said the little fellow, raising his hand, "my uncle is a county..."

  "Alright, the medicines I need are **, Ya**, and **. The names and quantities I'll write down for you. You go find your uncle right away and get these medicines delivered to Zhang Lao San's blacksmith shop." Qin Hai took out paper and pen from his bag, wrote a few names, and handed them over to the short guy.

  Now, several young people can only follow orders. They also hope that Qin Hai can create a miracle for them and turn the tide of being passive. The short-legged man took over the note handed over by Qin Hai, spread his two short legs, and ran towards the county town.

  After sending the short man away, Qin Hai called out and the rest of the people carried the farm tools on their stalls, led by the leading farmer, to an ironwork shop in a row of bungalows. On the door of the ironwork shop hung a sign with the words "Zhang Lao San" written on it.

  "Old Three, I've come to bother you with something," the leading peasant shouted.

  "Ah, you're back to buy something again? ... Hmm, why are there so many people?" Zhang Lao San came out of the house and was taken aback by the large number of people standing outside, each holding some farm tools.

  That peasant named Man Guo came forward and briefly explained the situation. Zhang Lao San took the rolled-up iron hoe from Man Guo's hand, looked at the blade, and said: "Hmmm, it's indeed good steel, what a pity... However, even if it were to be tempered again, using it to chop bricks would still be boasting."

  "Master Zhang, isn't this bragging? Can you let me try first? With such good steel, if the quenching is done well, splitting a common red brick should be no problem." Qin Hai said as he stepped forward.

  Zhang Lao San looked Qin Hai up and down and said: "You're the young man who knows how to temper fire? Where did you learn it?"

  Qin Hai Dao said: "I graduated from Provincial Agricultural Machinery Technical School and learned a little about quenching in school."

  "Haha." Zhang Lao San laughed, "What you learned in school is great! A newborn calf isn't afraid of a tiger. Here I have everything: the furnace, anvil, and water are all ready. Show me your skills and let this old blacksmith open his eyes!"

  His words were full of disdain, but his attitude was still quite enthusiastic. Quenching is not a difficult task, nor is it an easy one. The easy part is that it's just a matter of heating and then soaking in water. What makes it difficult is that the fire temperature has some subtleties, and the success or failure of quenching depends on the operator's judgment of the fire temperature.

  In Zhang Lao San's opinion, Qin Hai is probably a student who doesn't know the height of the sky or the thickness of the earth. He learned some superficial knowledge in school and wants to show off outside. He believes that Qin Hai will definitely try to temper the steel, but compared to this old blacksmith, the effect will be far inferior. Zhang Lao San himself can't even make these farm tools sharp enough to chop bricks, so for Qin Hai to achieve this effect is simply a joke.

  Qin Hai knew his age was a weakness, and if he wanted others to take him seriously, he had to produce solid results. He thanked Old Zhang and walked into the blacksmith's shop with the iron shovel head he had taken apart.