Carbon Steel: Properties, Production, Examples and Applications
Carbon steel is an iron-carbon alloy, which contains up to 2.1 wt.% carbon. For carbon steels, there is no minimum specified content of other alloying elements, however, they often contain manganese. The maximum manganese, silicon and copper content should be less than 1.65 wt.%, 0.6 wt.% and 0.6 wt.%, respectively.
Types of carbon steel and their properties
Carbon steel can be classified into three categories according to its carbon content: low-carbon steel (or mild-carbon steel), medium-carbon steel and high-carbon steel . Their carbon content, microstructure and properties compare as follows:
| Carbon content (wt.%) | Microstructure | Properties | Examples | 
| Low-carbon steel | < 0.25 | Ferrite, pearlite | Low hardness and cost. High ductility, toughness, machinability and weldability | 
| Medium-carbon steel | 0.25 – 0.60 | Martensite | Low hardenability, medium strength, ductility and toughness | 
| High-carbon steel | 0.60 – 1.25 | Pearlite | High hardness, strength, low ductility | 
Carbon Steel Description
Grade:
1)GB: Q195, Q215, Q235A, Q235B, Q235C, Q235D, Q255A, 255B, Q275, Q295A, Q295B, Q345B, Q345C, Q345D, Q345E, Q390A, Q390B, Q390C,Q390D, Q390E, Q420, Q420B, Q420C, Q420D, Q420E, Q460D, Q460E, Q500D, Q500E, Q550D, Q550E, Q620D, Q620E, Q690D, Q690E
2)EN: S185,S235JR, S275JR, S355JR, S420NL, S460NL S500Q, S550Q, S620Q, S690Q 
3)ASTM: Grade B, Grade C, Grade D, A36, Grade 36, Grade 40, Grade42, Grade 50, Grade 55, Grade 60, Grade 65, Grade 80 
4)JIS: SS330, SPHC, SS400, SPFC, SPHD, SPHE
PRODUCT DETAILS
| A36
  Round Steel Bar Description | 
| A36 is
  a carbon structural steel whose chemical composition and mechanical
  properties strictly conform to American ASTM standards. A36 steel bar mainly consists of iron, carbon,
  silicon, manganese, phosphorus, sulfur and other elements. Iron constitutes more than 99% of the entire chemical composition. Its carbon content proportion is relatively
  high, around 0.2%,
  ensuring that the steel has a certain hardness and toughness. The addition of
  silicon, manganese and other elements enhances the strength and toughness of
  steel. Phosphorus
  and sulfur are low so that the steel bar has
  good welding performance and corrosion resistance. A36 steel bar is used for
  welded, bolted or riveted construction of bridges and buildings, as well as
  for general structural purposes. Due to its lowest yield point, A36 can be
  used to design lighter-weight structures and equipment, and provide good
  weldability. | 
| Product   Parameters | 
| Product Name | A36 Round Steel Bar | 
| Standard | EN/DIN/JIS/ASTM/BS/ASME/AISI, etc. | 
| Common   Round Bar Specifications | 3.0-50.8 mm, Over 50.8-300mm | 
| Flat   Steel Common Specifications | 6.35x12.7mm, 6.35x25.4mm, 12.7x25.4mm | 
| Hexagon   Bar Common Specifications | AF5.8mm-17mm | 
| Square   Bar Common Specifications | AF2mm-14mm, AF6.35mm, 9.5mm, 12.7mm, 15.98mm, 19.0mm, 25.4mm | 
| Length | 1-6meters, Size Accept Custom | 
| Diameter(mm) | Hot Rolling   Round Bar | 25-600 | Cold   Rolling Square Bar | 6-50.8 | 
| Hot Rolling Square Bar | 21-54 | Cold   Rolling Hexagon Bar | 9.5-65 | 
| Cold Rolling Round bar | 6-101.6 | Forged Rebar | 200-1000 | 
| Surface Process | Bright, Polished, Black | 
| Other   Services | Machining(cnc), Centerless Grinding(cg), Heat   Treatment, Annealing, Pickling, Polishing, Rolling, Forging, Cutting,   Bending, Small Machining, etc. | 
| Chemical Composition | 
| C | Cu | Fe | Mn | P | Si | S | 
| 0.25~0.290 | 0.2 | 98 | 1.03 | 0.04 | 0.28 | 0.05 | 
| Physical
  Performance | 
| Physical Performance | Metric | Imperial | 
| Density | 7.85 g/cm3 | 0.284 lb/in3 | 
| Scope of
  Application | 
| Bolted,
  riveted or welded structures for bridges, buildings and oil drilling rigs. | 
| Used
  for forming storage tanks, silos, bearing plates, fixtures, rings, templates,
  fixtures, sprockets, cams, gears, bottom plates, forgings, decoration
  engineering, piles, brackets, automobiles and agricultural equipment, frames,
  mechanical parts, etc. | 
| Equivalent Material | 
| National
  Standard GB | European
  Standard EN | American
  Standard ASTM | German Standard DIN,WNr | Japanese
  Standard JIS | French Standard AFNOR | British
  Standard BS | Canada HG | 
| Q235B | S235JR | A283C | St37-2 | SM400A | E24-2 | 40A/40B | 230G | 
| Italy UNI | India IS | Switzerland SS | Australia ONORM | Norway NS | Spain UNE | International Standards ISO | Portugal NP | 
| Fe360B | IS2062 | 1311/1312 | RSt360B | NS12123 | AE235B-FN | E235B/Fe360B | FE360-B |