Carbon steel is an iron-carbon alloy with a mass fraction of carbon between 0.2 and 2.06% and a small amount of impurities such as Si, Mn, P, and S. According to its use, carbon steel can be divided into carbon structural steel, carbon tool steel and carbon cast steel. Carbon structural steel is divided into ordinary carbon structural steel and high-quality carbon structural steel according to metallurgical quality.
The smelting method of ordinary carbon structural steel is simple, and it contains many harmful impurities and non-metallic inclusions. The metallurgical quality of high-quality carbon structural steel is better, the amount of harmful impurities P, S and non-metallic inclusions are less, the uniformity and surface quality are better, and the chemical composition and mechanical properties of the steel must be guaranteed at the same time.
The carbon content of high-quality carbon structural steel is below 0.85%. According to the different manganese content, it is divided into two groups: ordinary manganese content (0.35~0.80%) and higher manganese content (0.70~1.2%). For a group with higher manganese content, add "Mn" after the steel number, such as 15Mn, 20Mn, etc.
High-quality carbon structural steel, referred to as high-quality carbon steel, is a steel plate used to manufacture parts and components of various machines.
1.08# steel and 08F are mainly used for rolling thin plates, deep-drawn products, oil drums, high-grade enamel products, and also for making pipes, gaskets and carburizing and cyanide parts that do not require high core strength.
2. No. 10 steel and 10F steel are mainly used for cold-pressed deep-drawing products below 4 mm, such as deep-drawing utensils, guns and bullets, and can also be used to manufacture boiler tubes, oil drum tops, steel strips, and mechanical parts.
3. No. 15 steel and 15F steel are used in the manufacture of mechanical carburized parts, fasteners, forging dies and without heat treatment low-load parts, such as flanges and chemical machinery receptacles, steam boilers, etc.
4.20# steel, used for various mechanical parts that do not withstand great stress and require toughness, such as tie rods, bushings, screws, lifting hooks, etc.: It can also be used to manufacture pipes used in non-corrosive media below 60 atmospheres and 450P It can also be used for carburized and oxidized parts with low core strength, such as bushings, chain rollers, shafts, and unimportant gears, sprockets, etc.
5.25 steel, used as mechanical parts for hot forging and hot stamping, cyanide parts on metal cutting machine tools, and shafts, washers, bolts, nuts, etc., which are not heavily loaded in heavy and medium machinery manufacturing, and can also be used as steel castings .
6.30 steel, used for hot forging and hot stamping machine parts, cold drawing, shafts, tie rods, collars for heavy and general machinery, and castings for machinery such as cylinders, steam turbine frames, rolling mill frames And parts, machine frame and flywheel, etc.
7. 35 steel, used to make machine parts for hot forging and hot stamping, cold drawn and cold upsetting steel, seamless steel pipes, parts in machine building, castings, forging shafts in heavy and medium machine building, compression It can also be used to cast steam turbine body, flywheel and equalizer, etc.
8.40 steel, used in the manufacture of machine moving parts, such as, shafts, connecting rods, discs, etc. As well as the axles of trains, it can also be used for cold drawing, steel plates, steel strips, seamless pipes, etc.
9. No. 45 steel is used to manufacture moving parts of steam turbines, compressors and pumps; it can also replace carburized steel to manufacture gears, shafts, piston pins and other parts; and can be used as castings.
10.No. 50 steel is used to manufacture parts with high wear resistance requirements and little dynamic load and impact, such as cast gears, tie rods, rolling spokes, etc. mandrels and shafts, etc., and can manufacture castings.
11.No. 55 steel is used to manufacture connecting rods, car L spokes, gears, flat springs, rims, rims, etc., and can also be used as castings.
12.60-65 steel is used to manufacture springs, spring rings, various washers, clutches and shafts, rolling spokes, eccentric shafts, etc. in general machinery.
13.No. 70-85 steel is used to make springs and springs, steel wires for wire ropes and high-hardness parts, such as ploughs, tram wheels, etc.
14.15Mn-25Mn steel is used to manufacture parts that require high mechanical properties of the central part and need to be carburized.
15.30Mn-35Mn steel is mainly used to make bolts, nuts, screw levers, pedals, etc. It can also use cold drawing to manufacture small parts that work under high stress, such as hooks, loops, chains, etc. on agricultural machinery.
16.40Mn-45Mn steel is used to manufacture parts under fatigue load, such as crankshafts, connecting rods, etc.; it can also be used as screws, nuts, etc. that work under high stress.
17.50Mn-55Mn steel is used to manufacture parts with high wear resistance and heat treatment under high load, such as gears, gear shafts, friction discs, rollers and springs.
18.60Mn-70Mn steel, used in the manufacture of springs and other components.