Carbon tool steel: hammers, punches, chisels, woodworking tools, scissors, taps, drills, dies, hand saw blades, files, scrapers, razors, measuring tools, etc.
Cast carbon steel: automobile gearbox housing, couplers and couplings of rolling stock, etc.
Question 2: What are the heat treatment methods of low carbon steel? The commonly used heat treatment process of steel is as follows: 1. Quenching of sub-* * steel, that is, low-carbon steel and medium-carbon steel are heated to 30-50℃ above Ac3, and kept at this temperature for a period of time, so that all the steel structures become austenite, and then cooled rapidly (water cooling or oil cooling), so that austenite cannot be decomposed to form martensite structure. This quenching is called quenching. 2. Tempering Tempering is a heat treatment method of reheating the quenched workpiece to a certain temperature below A 1, keeping the temperature for a period of time, and then cooling it in air or water. The purpose of tempering is to reduce the hardness of quenched steel, improve plasticity and toughness, reduce internal stress and adjust microstructure to obtain good comprehensive mechanical properties. Tempering temperature can be divided into low temperature tempering (150-250℃), medium temperature tempering (350-450℃) and high temperature tempering (500-650℃). 3. Quenching and tempering Some alloy steels are tempered at high temperature immediately after quenching, which is called quenching and tempering. 4. Normalizing to heat the steel to 30-50℃ above Ac3 or Accm, and then cooling it in the air after heat preservation. After normalizing, many carbon steels and alloy steels have good mechanical properties and can refine grains. For welded structures, normalizing can improve the weld quality and eliminate coarse grains, hardened structures and uneven structures in the weld area. 5. Annealing is the process of heating the steel to 30-50℃ above Ac3 or Ac 1, keeping the temperature for a period of time, and then slowly and uniformly cooling it, which is called annealing. Annealing can reduce hardness, make materials easy to cut, refine steel grains and eliminate stress. Heat the steel to below Ac 1 (generally 600-650℃), keep the temperature for a certain period of time, and then cool it in air or furnace. This is stress-relieving annealing, also called low-temperature annealing. Stress relief annealing is mainly used to eliminate welding residual stress of welded structure.
Question 3: What are the common sense questions about plastics in life?
Television housings, computer display housings and car interiors are usually made of polystyrene. Many toys are made of polystyrene, and the cushioning material of packaging is also expanded polystyrene. Polystyrene is one of the most commonly used plastics, abbreviated as PS, which was invented around 1930.
Generally, the washbasin and bucket in the home are made of polypropylene. The abbreviation of polypropylene is PP.
ABS is a new type of engineering plastic with high price, which is mainly used in mobile phones, mice and advanced household appliances. ABS has high strength and is not easy to crack, so some people call it ABS unbreakable resin.
Generally speaking, food plastic bags are made of polyethylene. Polyethylene is very soft, and the English abbreviation is PE.
There is a kind of toxic plastic called PVC. It is forbidden to use PVC as tableware or faucet. The abbreviation of PVC is PVC.
The bucket and medicine bag of the automatic water supply machine are made of polycarbonate, and the English abbreviation is PC. Polycarbonate is a common decorative and engineering material.
The abbreviation of nylon is PA, which was invented in 1935. Such as nylon rope, nylon zipper, etc. Generally speaking, gears in clocks and toys are made of nylon.
Porcelain-like tableware is made of melamine resin, abbreviated as MF in English, commonly known as melamine resin, which has the characteristics of high temperature resistance, corrosion resistance, beauty and not easy to break.
HDPE: high density polyethylene
LDPE: low density polyethylene
AS: a transparent engineering plastic
PET: a packaging material
HIPS: impact polystyrene. Because it contains a small amount of rubber, the impact strength is greatly improved.
PMMA: polymethyl methacrylate, commonly known as plexiglass.
PBT: engineering plastics
ASA: An Engineering Plastic with Good Aging Resistance
ACS: An Engineering Plastic with Good Fire Resistance
Polyethylene is polymerized by ethylene gas at high temperature (200-300 degrees Celsius) and high pressure (100-300MPa) with a small amount of titanium tetrachloride as catalyst, and other plastics are also produced in a similar way.
About metals:
Knives, scissors and nail clippers are generally made of high carbon steel with high carbon content, high hardness and wear resistance.
Table legs, chair legs, engineering steel frames and steel bars generally use medium carbon steel with medium carbon content and high mechanical strength.
Water pipes and heaters are made of low carbon steel, which has low carbon content, good toughness and is not easy to rust.
The scientific name of stainless steel is nickel-chromium alloy steel. Because it contains two kinds of metals that are not easy to corrode, and there are few impurities, it is not easy to rust. Chromium is used to increase hardness.
Sometimes the surface of iron products is black, which is the color of ferroferric oxide. Usually rust is red, called iron oxide. Sometimes the surface of iron products will be specially coated with a layer of ferroferric oxide to prevent rust.
There is a kind of brass that is almost the same color as gold, and that is copper-zinc alloy. There is a kind of white copper that is almost the same color as silver, and that is copper-nickel alloy.
Aluminum alloy refers to an alloy made by adding magnesium, copper, manganese, silicon, titanium and other elements to aluminum. Generally speaking, aviation aluminum alloy is only higher in purity than ordinary aluminum alloy and is not used in real aircraft. Generally, aluminum alloys of airplanes contain a small amount of titanium, because titanium is the strongest metal in the world. American stealth fighter f22 has the highest titanium content, reaching 42%, while composite material accounts for 23% and aluminum alloy only accounts for 15%, which shows its advanced nature. At present, the price of some high-grade aluminum alloy doors and windows is twice that of ordinary aluminum alloy doors and windows, and it also contains a small amount of titanium.
The bucket of track and excavator is made of manganese steel with high strength and wear resistance.
The spring is made of silicon manganese steel with good elasticity.
The gun barrel and barrel are made of tungsten steel, which can resist high temperature, because tungsten is the highest melting point metal, with a melting point of 34 10 degrees.
Metal density (g/cm3)
Copper 8.9
Iron 7.8
Titanium 4.5
Aluminum 2.7
The hardest metal is chromium, which is harder than glass. The lowest hardness metal is sodium, which can be easily cut with a knife.
Mercury is the lowest melting point metal, with a melting point of MINUS 38.8 degrees. Usually, mercury is a liquid, commonly known as mercury.
About the battery:
At present, the capacity of alkaline batteries is about a quarter of that of gasoline with the same volume, and the capacity of lithium batteries for cameras is about half of that of gasoline with the same volume. Although the old zinc-manganese battery is cheap, its capacity is too small. Actually ... >>
Question 4: The use of low carbon steel and stainless steel is the first. Low carbon steel = low carbon steel is easy to accept all kinds of forging, welding and cutting, and can manufacture chains, rivets, bolts, shafts, etc.
Carbon steel with carbon content below 0.25% is also called low carbon steel because of its low strength and hardness. Include ordinary carbon structural steel and high-quality carbon structural steel.
Low carbon steel is generally rolled into angle steel, channel steel, I-beam, steel pipe, steel strip and steel plate, which are used to manufacture various building components, containers, boxes, furnaces and agricultural machinery. High-quality low-carbon steel is rolled into thin plates and made into deep-drawing products such as automobile cab and hood; Made into bars, used to manufacture mechanical parts with low strength requirements. Low carbon steel is limited in use because of its low strength. The strength of carbon steel can be greatly improved by appropriately increasing the manganese content in carbon steel and adding trace alloying elements such as vanadium, titanium and niobium.
Stainless steel. Most tableware in our life is made of stainless steel.
Question 5: What gas is better for cutting carbon steel in daily life? What gas is better for cutting carbon steel in daily life?
But the plasma arc cutting effect is good. It is a machining method that uses the heat of high-temperature plasma arc to locally melt (and evaporate) the metal at the notch of the workpiece, and uses the momentum of high-speed plasma to remove the melted metal to form the notch.
Plasma cutting with different working gases can cut all kinds of metals that are difficult to be cut by oxygen, especially non-ferrous metals (stainless steel, aluminum, copper, titanium and nickel). Its main advantages are that when cutting metal with small thickness, the plasma cutting speed is fast, especially when cutting ordinary carbon steel sheet, the speed can reach 5~6 times that of oxygen cutting method, the cutting surface is smooth, the thermal deformation is small and the heat affected zone is few.
Question 6: What steel makes a good tool steel in life?
high-speed steel
4Gr 13
9Gr 13
Question 7: Is 35 steel low carbon steel? 35 steel is medium carbon steel, and below 20 is low carbon steel.
Question 8: Carbon steel, iron or steel? Usually I ask whether it is iron or steel. I just want to ask if the material is hard or not. Carbon steel is divided into high, medium and low carbon. Some people will call low-carbon steel (soft and low tensile strength) iron. Still molten steel is not good.
Strictly speaking, only pure iron (Fe) is iron. Steel is the general name of iron-carbon alloy with carbon content of 0.02%-2. 1 1%. The chemical composition of steel varies greatly. Steel containing only carbon element is called carbon steel (carbon steel) or ordinary steel. In actual production, steel often contains different alloying elements, such as manganese, nickel and vanadium, according to different uses.
Basically, the steel products we see in our daily life should be called XX steel.