Carbon Structural Steel Plate

Carbon Structural Steel Plate is a common type of structural steel, which can be divided into two categories: ordinary carbon structural steel and high-quality carbon structural steel. The former contains more impurities, is inexpensive and is used in places where the performance requirements are not high, and most of its carbon content is below 0.30% and manganese content is not more than 0.80%, with lower strength but good plasticity, toughness and cold deformation properties. Except for a few cases, it is generally not heat-treated and used directly. It is mostly made into bar steel, special-shaped steel, steel plate, etc. Uses a lot, with a large amount, mainly used for railroads, bridges, various types of construction projects, the manufacture of all kinds of metal components to withstand static loads and does not require heat treatment is not important mechanical parts and general weldments. High-quality carbon structural steel steel is pure, few impurities, good mechanical properties, can be used after heat treatment. According to the manganese content is divided into ordinary manganese content (less than 0.80%) and higher manganese content (0.80% ~ 1.20%) two groups. Carbon content of 0.25% or less, more direct use without heat treatment, or by carburizing, carbonitriding and other treatments, the manufacture of small and medium-sized gears, shafts, piston pins, etc.; Carbon content of 0.25% to 0.60%, the typical steel 40, 45, 40Mn, 45Mn, etc., and more by the quenching process, the manufacture of a variety of mechanical parts and fasteners, etc.; Carbon content of more than 0.60%, such as 65, 70, 85, 65Mn, 70Mn, etc., more as the use of spring steel. Its main components are carbon and iron, usually contains a small amount of other alloying elements. Carbon structural steel is one of the simplest types of steel with good weldability, workability and relatively low cost.

The characteristics of carbon structural steel plates are as follows:
1. Carbon structural steel has low carbon content and high manganese content, which is beneficial to improve the welding performance of steel;
2. Carbon structural steel has strict control over impurities such as sulfur and phosphorus, and the higher the level, the less impurities;
3. The impact toughness of carbon structural steel is higher, which can better meet the needs of professional steel;
4. The performance indicators of carbon structural steel are graded according to the thickness of the steel, which is conducive to expanding the scope of use of steel;
5. The output and consumption of carbon structural steel are large, and it is often used in the manufacture of welded structures and engineering structures.
Carbon structural steel is normally used directly in the state of supply without heat treatment. The properties and applications of commonly used carbon structural steels are mainly:

Q195 Q215
Main characteristics: high plasticity, toughness and weldability, good pressure machinability, but low strength.
Applications: Used in the manufacture of ground bolts, plowshares, smoke pipes, roofing panels, rivets, mild steel wire, thin plate, tie rods, and welded architectures.

Q235(A3)
Main characteristics: good plasticity, toughness, and weldability, cold stamping properties, as well as a certain strength and good elongation, good cold bending properties.
Applications: Widely used for general requirements of parts and welded structures, belonging to the low carbon steel,usually hot rolled into steel plate , steel profiles, steel strength. Usually used in the manufacture of structural building parts, vehicles, unimportant shafts, screws, nuts, stampings, forgings, weldments.

Q255
Main characteristics: good strength, plasticity, toughness, good weldability and cold and hot pressure processing performance.
Application: Used in the manufacture of parts requiring low strength, bolts, keys, shafts, and various profiles for steel structures, steel plates.

Q275
Main characteristics: high strength, good plasticity and cutting performance, certain welding performance. Small parts can be quenched and strengthened.
Application: Used in the manufacture of parts requiring not too high strength, such as gears, shafts, sprockets, keys, bolts, nuts, steel sections for agricultural machinery, conveyor chains and links.
Where Q235 is what we usually call A3, in the equipment generally with sheet metal parts.

National standards for carbon structural steel plate may vary from country to country. The following are some representative national standards for carbon structural steel plate:

GB Standard:
China's carbon structural steel standard for GB/T 700-2006. this standard specifies the carbon structural steel grade, classification and code, size, shape, weight, technical conditions, inspection and test, packaging marking and quality certification.

ASTM standard:
American Society for Testing and Materials (ASTM) developed a standard for carbon structural steel, the implementation of the standard ASTM A36/A36M-03a, this standard applies to bridges and construction of riveted, bolted and welded structures, as well as general-purpose structural steel qualities of carbon steel profiles, steel plates and bars.

British Standards：
BS EN 10025-2:2004 - Standard for non-alloy structural steels for hot-rolled products.
BS EN 10025-3:2004 - Standard for orthogonally welded structural steels for hot rolled products, including normal strength and high strength steels.
BS EN 10025-4:2004 - Structural steel standard for prescribed welding techniques for hot-rolled products, suitable for both orthogonal and circumferential welding.
BS EN 10025-5:2004 - Standard for weathering steels for structural purposes, for structural steels with good weathering properties.
BS EN 10025-6:2004 - Standard for high strength steels for hot rolled products, suitable for orthogonal and circumferential welding.

Japanese Standards：
JIS G3101 - Standard for hot-rolled coils of general construction.
JIS G3106 - Standard for hot-rolled coils for welded structures.
JIS G3131 - Standard for hot-rolled ordinary steel coils.
JIS G3141 - Standard for Cold Rolled Sheet and Strip.
JIS G4051 - Standard for engineering structures of carbon steel, including carbon steel for various purposes.

At present, the implementation standard of carbon structural steel in China's steel market is "GB/T 700-2006". According to the composition and performance requirements, such steel grades by Q195, Q215A, B, Q235A, B, C, D, Q255A, B, Q275 and other grades. Q255 and Q275 steel carbon mass fraction is slightly higher, higher strength, plasticity, toughness, can be welded, usually rolled molding steel, steel and steel plate for structural components and the manufacture of simple machinery, connecting rods, gears, couplings, pins and other parts.
The following are the general provisions of the GB/T 700-2006 standard on the dimensions and allowable deviations of some common steel products:

Q215 steel plate
Thickness: between 3mm and 25mm;
Width: between 1000mm and 1500mm;
Length: between 2000mm and 12000mm.

Q235 steel plate
The thickness should be between 1.5 mm and 100 mm;
Width should be between 1000mm and 2500 mm;
The length should be between 2000mm and 12000mm;
The thickness, width and length of the steel plate shall be checked according to the tolerances specified in the standard.

Q255 steel plate
Thickness should be between 2mm and 650mm;
The width should be between 1000mm and 4020 mm;
The length should be between 3000mm and 18800mm.

Q275 steel plate
Thickness should be between 10mm and 250mm;
Width should be between 1840mm and 3600 mm;
The length should be between 8000mm and 13000mm.

Dimensions and allowable deviation Thickness is ±0.5mm; width allowable deviation is ±10mm; length allowable deviation is ±20mm.