Low, medium and high carbon steel coil
Steel is an iron carbon alloy with carbon content between 0.04% - 2.3%. In order to ensure its toughness and plasticity, the carbon content generally does not exceed 1.7%. In addition to iron and carbon, the main elements of steel also include silicon, manganese, sulfur, phosphorus and so on. Carbon steel is an iron carbon alloy with carbon content of 0.0218% ~ 2.11%. Also called carbon steel. Generally, it also contains a small amount of silicon, manganese, sulfur and phosphorus. Generally, the higher the carbon content in carbon steel, the greater the hardness and strength, but the lower the plasticity.
1.carbon steel coil properties:
Low carbon steel coil (C: ≤ 0.25%) is also known as mild steel.
Low carbon steel properties is easy to accept various processing, such as forging, welding and cutting. It is often used to manufacture chains, rivets, bolts, shafts, etc.
Medium carbon steel coil properties (C: 0.25% < C ≤ 0.6%) has killed steel, semi killed steel, boiling steel and other products.
In addition to carbon,Medium carbon steel coil properties can also contain a small amount of manganese (0.70% ~ 1.20%). According to the product quality, it is divided into ordinary carbon structural steel and high-quality carbon structural steel. Good hot working and cutting performance, poor welding performance. The strength and hardness are higher than that of low carbon steel, while the plasticity and toughness are lower than that of low carbon steel. Hot rolled and cold drawn materials can be directly used without heat treatment, and can also be used after heat treatment. The medium carbon steel after quenching and tempering has good comprehensive mechanical properties. The highest hardness that can be achieved is about hb538, with tensile strength σ B is 600 ~ 1100mpa. Therefore, medium carbon steel is the most widely used in various applications with medium strength level. In addition to being used as building materials, it is also widely used to manufacture various mechanical parts.
High carbon steel coil properties (C: > 0.6%) is often called tool steel.
The carbon content ranges from more than 0.60% to 1.70%, which can be hardened and tempered. Hammers, crowbars, etc. are made of steel with a carbon content of 0.75%; Cutting tools such as drills, taps, reamers, etc. are made of steel with a carbon content of 0.90% to 1.00%.
The higher the carbon content, the greater the hardness and strength, but the lower the plasticity
(in addition, iron carbon alloy with carbon content of 2.1% ~ 4.5% is generally called cast iron.)
2. According to the mass of steel coil (mainly the content of impurity sulfur and phosphorus):
Ordinary carbon steel (s ≤ 0.055%, P ≤ 0.045%)
High quality carbon steel (s ≤ 0.040%, P ≤ 0.040%)
High quality carbon steel (s ≤ 0.030%, P ≤ 0.035%)
3. By carbon steel coil:
Carbon structural steel: mainly used for bridges, ships, building components, machine parts, etc
Carbon tool steel: mainly used for cutting tools, molds, measuring tools, etc
Carbon steel coil grade and application
1. Ordinary carbon structural steel: carbon structural steel is divided into five grades according to the yield strength of steel: Q195, Q215, Q235, q255 and Q275. Due to different quality, each brand is divided into grades A, B, C and D. Q195, Q215 and Q235 have good plasticity and can be rolled into steel plate, reinforcement and steel pipe; Q255 and Q275 can be rolled forming steel, steel plate, etc.
2. High quality carbon structural steel: the steel grade is expressed by the average mass fraction of carbon. Such as 20, 45, etc. 20 means containing C: 0.20% (20 / 10000). Purpose: mainly used for manufacturing various machine parts
3. Carbon tool steel: the steel grade is expressed by the average mass fraction of carbon and preceded by T. Such as T9, T12, etc. T9 means containing C: 0.9% (9 / 1000). Usage: mainly used for manufacturing various cutting tools, measuring tools, molds, etc
4. Cast steel: the grade of cast steel is preceded by ZG, and the number represents the average mass fraction in steel (expressed in 10000 fractions). For example, ZG25 indicates that the content of C is 0.25%. Usage: mainly used for manufacturing parts with complex shape and requiring certain strength, plasticity and toughness, such as gears, couplings, etc.
Difference between ordinary carbon steel coil and ordinary steel coil
Carbon steel coil: carbon steel is a carbon steel with carbon content less than 0.8%. This steel contains less sulfur, phosphorus and non-metallic inclusions than carbon structural steel, and has excellent mechanical properties. According to different carbon content, carbon steel can be divided into three categories: low carbon steel (C ≤ 0.25%), medium carbon steel (C = 0.25-0.6%) and high carbon steel (c > 0.6%).
Steel coil: it is a flat steel plate cast with molten steel and pressed after cooling. Common materials include carbon steel, high-quality steel, alloy steel, spring steel, stainless steel, tool steel, heat-resistant steel, bearing steel, silicon steel and industrial pure iron plate.
Difference between ordinary carbon steel plate and ordinary steel plate: ordinary steel plate includes ordinary carbon steel plate, which is a kind of ordinary steel plate.
Difference between carbon steel coil and hot rolled steel
Carbon steel refers to iron carbon alloy with carbon content less than 2% and a small amount of silicon, manganese, phosphorus, sulfur and other impurities. The carbon content of carbon steel coils used in industry generally does not exceed 1.4%. This is because when the carbon content exceeds this amount, the steel shows great hardness and brittleness, and it is difficult to process and lose the value of production and use. According to their different quality, carbon steel can be divided into ordinary carbon structural steel and high-quality carbon structural steel. The allowable content of sulfur and phosphorus of high-quality carbon structural steel is lower than that of ordinary carbon steel, so the comprehensive mechanical properties are better than ordinary carbon steel.
In short, the process of rolling steel after heating and controlling it above the recrystallization temperature is called hot rolling. The process of rolling below the recrystallization temperature, including normal temperature, is called cold rolling.
Hot rolled steel has good plasticity and is easy to form. After forming, the steel has no internal stress, which is convenient for the following processes. For example, steel bars for construction, steel plates for stamping, and steel to be machined and heat treated are all hot-rolled steel.
Cold rolled steel has the characteristics of cold work hardening. Because cold rolling has good mechanical properties, many directly used steels use cold rolled steels. Such as cold-rolled twisted steel bars, cold-rolled steel wires, cold-rolled steel plates, etc
So they are inclusive. Carbon steel includes hot rolled steel.
What is Q235 is a carbon structural steel?
Q235 is a carbon structural steel, which is the most commonly used steel material.
Q is the first letter of the Chinese phonetic alphabet of "yield" of steel, 235 refers to the yield strength, Q235C and q235d are the quality grades C and D of carbon structural steel, which are used in important welded structures. The coil identification - 5 * 1.25 refers to the thickness of 5mm, the width of 1.25m and - 10 refers to the thickness of 10mm
There are many specifications if flat steel, medium plate and flat rolled plate are considered
The thickness is 3-200mm, each integer has;
450-4800mm wide and 25000mm long
How to prevent low, medium and high carbon steel coil from rusting
We all know that one of the obvious disadvantages of carbon steel coil products compared with stainless steel is that it is easy to rust, which is not as durable as stainless steel. In order to make carbon steel products not so easy to rust, what will be done?
First of all, it depends on whether the demand is long-term rust prevention or short-term.
If it is necessary to prevent the carbon steel coil from rusting for a long time, the surface treatment is generally done.
Hot dip galvanized carbon steel coil
Of course, the better effect is hot galvanizing. Immerse the derusted carbon steel coil into the molten zinc of about 500 to make the surface of the steel member adhere to the zinc layer. Of course, the price of this treatment is relatively high.
Chromium, nickel, zinc, etc
The cost is not so high, such as chromium plating, nickel plating, zinc plating, etc. Among them, galvanizing is a conventional and frequently used surface treatment method. It should be noted that galvanizing here refers to cold galvanizing (i.e. electro galvanizing), which is different from hot galvanizing above. It is thinner than hot galvanizing in thickness and has poor corrosion resistance.
If the carbon steel coil is rusted for a short time
This temporary rust prevention is generally to spray carbon steel coil with antirust oil or antirust liquid. The antirust time of antirust oil is longer than that of the latter, but if the antirust fluid needs to be sprayed, it can be sprayed directly without cleaning.
According to different carbon steel products, there are also different treatment methods. For large and irregular products, paint baking, plastic spraying and painting can be used (among which the paint baking is the most expensive and the best effect); The parts with assembly on the surface can be coated with antirust oil. If the requirements are higher, they can be plated with chromium, with good hardness and controllable size.
Safety code for stacking carbon steel coils
The stacking of carbon steel coils also depends on the packaging, material and weight of a single coil. Generally, there are two layers. If it is a large coil of more than 5 tons, try to put it alone, or two with one, small tonnage and high hardness, such as high-speed wire, spiral screw and 3-4 layers. Galvanized coil, silicon steel coil, etc. generally up to 2 layers. If there is no special site and shelf, wooden blocks shall be padded to prevent rolling