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 |
PRODUCT DETAILS
| Q355B / Q355C Carbon Steel Coil |
Q355B and Q355C hot rolled high-strength low-alloy (HSLA) steel coils are premium heavy-load structural grades, equivalent to S355JR and ASTM A572 Gr50. Delivering 355MPa minimum yield strength and improved low-temperature toughness, these coils excel in heavy structural fabrication. Widely adopted for solar brackets, container frames and engineering machinery parts, they provide rigid, durable support for high-load industrial and infrastructure projects. If you are in market for our carbon steel coil products, welcome to contact us for further cooperation. Head to our product page to discover more new steel products! |
| Product
Parameters |
|
| Product
Name | Q355B / Q355C Carbon Steel Coil |
| Production
Process | Hot Rolling,
Cold Rolling |
| Material
Standards | GB/T 1591-2018 Equivalent: EN S355JR, ASTM A572 Grade 50 |
| Regular Size | Common Thickness 2.0mm – 20mm | Hot sale sizes: 3.0, 4.0, 6.0, 8.0, 10.0, 12.0mm Standard Dimensions Width: 1250mm / 1500mm / 1800mm / 2000mm Custom slitting & fixed cutting available |
| Surface Treatment | Standard hot rolled black surface Pickled & oiled for precise machining Anti-rust oil coating for ocean shipping Edge deburring for structural welding usage |
| Delivery Temper | Hot rolled controlled rolling; normalized optional for critical thick structural coils |
| Full Supporting Certificates | EN10204 3.1 MTC, SGS/BV third-party mechanical test report, low-temperature impact test certificate, ultrasonic UT inspection report, CE certification for EU engineering tender projects |
| Exported to | Middle East (Saudi Arabia, UAE); Southeast Asia (Vietnam, Thailand);base Australia; Domestic & Central Asia |
| Core Strengths |
355MPa high yield strength, far stronger than ordinary carbon steel, reduces structural material thickness and overall project weight Q355B features normal-temperature impact resistance; Q355C offers enhanced 0℃ low-temperature toughness for variable climate construction Superior structural stability and fatigue resistance, ideal for long-term heavy load and outdoor wind pressure environments Excellent weldability and formability, fits continuous rolling, bending and cutting for mechanical and profile production Global standard interchangeability with S355JR / A572 Gr50, fully compatible with international engineering specifications Uniform alloy composition and stable tolerance, suitable for automated mass production of structural profiles |
| Scope of Application |
Photovoltaic industry: Solar mounting brackets, ground & rooftop PV support structures Logistics & transportation: Container side panels, chassis frames, trailer girders Engineering machinery: Equipment base supports, boom structural parts, heavy machinery housings Construction engineering: High-load factory frames, large-span steel structures, bridge auxiliary components Industrial profile: Thick-walled structural tubes and heavy-duty fabricated fittings |
