A good sword, is its blade the same as the blade?

Today, the standard of a good knife is an era when knives are strictly controlled, and the use and dependence have been greatly reduced. However, men are somewhat heroic. Although they can only occasionally peel a fruit, shave a beard, sharpen a pencil for their children and play occasionally, there are still standards for a good knife. Personally, today's good Dao generally has the following evaluation criteria: 1. Sharp: This is. 2. Resilience: Daughter-in-law occasionally cuts off a bone, and when a son cuts off a stone, it will break his blade and gouge out his teeth. It can only be used as decoration, but that won't do. 3. Hardness: Cutting one barbecue at a time will be dull. If you cut a hard object, it will be a groove. If you grind the knives at both ends every three days, it won't work. 4. Stainless: I broke the mud in the water and put it in the sheath as soon as I came back to wash it dry. A month later, it is still extremely sharp and convenient. This is a good knife. Other appearance modeling, scabbard decoration and so on vary from person to person, depending on their own aesthetics and tone.

1. Tool material selection The steel we are talking about is an iron-carbon alloy, and the range of carbon content from 0 to 2.26% is called "steel", with 2.26%-

The range of 4.3% is called "cast iron". Within the scope of steel, the most basic rule is that the higher the carbon content, the higher the hardness and the lower the toughness, and the easier it is to quench. Adding alloying elements to steel is called alloy steel. According to alloy content, it can be divided into low alloy steel and high alloy steel. The effect of adding alloying elements is to change the metallographic structure and improve the properties, such as corrosion resistance, heat resistance, strength increase and diamagnetism. For example, the casting performance of aircraft carrier plates and turbofan blades. I won't go into details about the mechanism and professional knowledge here. In a word, it is a prosperous era of science and technology, and the existing steel metallurgical technology can completely tailor a kind of steel for you. At present, there are several kinds of commonly used steel or easily found materials used as cutting tools: a. The commonly used stainless steel is 0Cr 18Ni9Ti, commonly known as 18-8 stainless steel, which makes the cutting tools shiny and rust-free, beautiful, sharp when used for the first time, but it should be sharpened frequently. The carbon content is lower than 0. 1%. Because the carbon content is too low and soft, it is impossible to quench. So it is best not to use stainless steel as a tool. It is also not recommended to buy a stainless steel kitchen knife, which is easy to blunt. Science popularization: It is also unscientific to identify stainless steel with magnets. Some stainless steels are magnetic, some are not, and some are not at a certain temperature. B. Common brands of ordinary steel plates: A3, Q235, 16Mn, 20, with carbon content less than 0.25%, commonly known as low-carbon steel, and I-beams, angle steel and other profiles, have good weldability and moderate strength and toughness, and are the most widely used metal structural materials and building materials in the world. It is also because of low carbon content, low hardness and no fire after quenching, so it is not recommended to use tool materials. Most dogs in the world bite bones with low-carbon steel kitchen knives. Popular science: the famous "Golden Gate Kitchen Knife" is also somewhat unreliable. If it is a warhead from the mainland, there are only fragments of copper, lead and tungsten steel heads. Tungsten steel is a superhard material, which can't be used as a knife at all, similar to the small black block on the tip of a turning tool. If it is a shell in Taiwan Province Province, it is copper plated on low carbon steel. To make a shell, you need to punch it. Imagine how malleable it is. Personally, I think the blade of Jinmen kitchen knife has processing technology, or the blade design is more scientific, or medium carbon steel is used. Popular science: simple identification of low carbon steel. Two kitchen knives knocked on the back, and the low carbon steel with dents was because it was the softest steel. C. Common brands of medium carbon alloy quenched and tempered steel: 40Cr and 35CrMo, with carbon content of 0.3.

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0.6%, commonly used: machine shaft, gear, water pump shaft, motor shaft. Moderate performance, good strength and toughness, high surface hardness, easy quenching, easy to find, is an ideal material for various tools. Difficulties: Most of them are shaft parts, which need to be forged into plates by blacksmith's shop first, and then quenched and tempered to ensure the toughness and hardness of the internal surface. Science popularization: quenching and tempering: it is a kind of heat treatment of steel, first quenching and then tempering at high temperature. D common brands of alloy spring steel: 65Mn and 55Si2Mn, with carbon content of 0.35%.

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0.7%, commonly used: car leaf spring, steel wire coil spring. It has strong toughness, hard surface and easy to find, and is an ideal tool material. E. Common brand of bearing steel: GCr9, with carbon content of 0.95.

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1. 15%, commonly used: bearing inner and outer rings, needle valve. High hardness, wear resistance, easy quenching and easy to find waste bearings. Colleagues around me have cut off the outer ring of the waste bearing and smashed it into a knife or axe. However, personally, because the hardness is too high, it is easy to quench and crack, so it is not suitable for making knives and has poor toughness. Other common tool steels (files) and high-speed steel (machine tools) are obviously too hard and basically have no toughness, so they are not suitable for cutting tools. So the most common materials suitable for cutting tools are medium carbon alloy quenched and tempered steel and alloy spring steel.

2. Material Processing Once the material is selected, you can make your own knife. The specific steps are as follows: annealing, processing and molding, heat treatment, finishing, surface treatment and cutting, which are specifically introduced as follows: a. Annealing The above materials are generally processed scrap parts, and the surface treatment is hard, so it is necessary to burn red first, and then slowly air-cool or cool with the furnace to restore the materials to their original state. Popular science: heat treatment: heating the workpiece to a certain temperature, and then cooling it at different speeds to change the structure and properties. Annealing: the workpiece burns red and is slowly cooled in the air, or kept for a period of time or slowly cooled with the furnace to restore the material to its original state, with the aim of restoring toughness and plasticity. Quenching: the workpiece burns red and cools rapidly in water, salt water and oil, so that the hardness of the material is improved and the corresponding toughness is reduced, with the aim of improving the hardness. Carburizing: increase the carbon content of metals, such as low-carbon steel tools, coat the cutting edge with plant ash and bone powder, and put it in a certain temperature insulation environment for a period of time, so that carbon elements can penetrate into the surface of the cutting edge to make other parts reach toughness, and the cutting edge can be quenched and hardened. In ancient times, adding wood and forging steel was carburizing. Popular science: roughly judge the heating temperature of steel by color: dark red: 400-500; Red: 500-600; Yellow: 600-700; Huang Bai: 700-900. B. Forming: hacksaw, grinder C. Heat treatment Heat treatment is an experienced process. The quenched blade may crack, become shallow when it comes out of water, and grind out a hardened layer after cutting. The best state is that the blade is hard and sharp, and the whole has toughness and strength. D grinding stones and fine sandpaper for dressing should be pushed slowly and repeatedly, mainly to ensure smooth surface, straight edges and corners and smooth curves. E, carrying out surface treatment on the commercially available passivation paste or passivation solution, and coating the metal surface for a period of time to form an oxidation-resistant passivation film without rusting. Now with nano-coating technology, the purpose is the same. The surface can be treated with nitric acid, alcohol and caustic soda with a certain concentration. Some people use aqua regia to corrode and appear patterns, but the corrosion is strong, which makes them feel unscientific and damages the performance of tools. F. The smaller the acute angle of the handle, the flatter and sharper the two blade surfaces, but it is also easier to break the blade. I think the angle is more appropriate. For example, the performance of selling kitchen knives to cut nails and wire kitchen knives, the blade angle is large, and it is not suitable for cutting vegetables. It needs to be carefully polished with oilstone and fine sandpaper. This is a delicate job and requires patience. It is often said that Japanese Taidao is magical, but in fact, careful sharpening has played a great role. At present, the processing level of the machine is very high. If there are fine serrations on the blades and there are fine and even grooves on the surfaces of the two blades, this is the sharpest state. Many tools with poor material selection have become sharp, which is also closely related to advanced processing methods. So a good knife is the embodiment of the best combination of various standards. Source:/topic-4093500-1-1.html.