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 DescriptionGrade: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, Q690E2)EN: S185,S235JR, S275JR, S355JR, S420NL, S460NL S500Q, S550Q, S620Q, S690Q3)ASTM: Grade B, Grade C, Grade D, A36, Grade 36, Grade 40, Grade42, Grade 50, Grade 55, Grade 60, Grade 65, Grade 804)JIS: SS330, SPHC, SS400, SPFC, SPHD, SPHEPRODUCT DETAILS
| AISI/SAE 1018 Round Steel Bar Description |
| 1018 cold rolled steel bar is made of a general-purpose, low-carbon steel with good case hardening qualities. It is especially suited to cold forming and bending operations. 1018 steel is suitable for parts that require cold forming such as crimping, swaging, or bending. 1018 steel is mild steel with medium-low carbon content. AISI 1018 carbon steel is a free machining grade that is the most commonly available grade around the world. Although its mechanical properties are not very unique, it still can be easily formed, machined, welded and fabricated. |
| Product Parameters |
| Product Name | AISI/SAE 1018 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 | 6.35×12.7mm, 6.35×25.4mm, 12.7×25.4mm |
| 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 |
| Carbon Steel | C | Fe | Mn | P | S |
| 1018 | 0.14-0.20% | 98.81-99.26% | 0.60-0.90% | 0.04% | 0.05% |
| Mechanical Properties |
| Tensile Strength | Yield Strength | Elongation % | Hardness(Brinell) | Hardness(Rockwell B) |
| 440MPa | 370MPa | 22 | 126 | 71 |
| Scope of Application |
| Carburized parts, including worms, gears, pins, pins, tools and non-critical parts of mold sets; tool brackets, pinions, mechanical parts, ratchets, positioning pins and chain pins. |
