S355JRSquare tube is a low-alloy high-strength structural steel square tube，Widely used in architecture、Machinery manufacturing、Bridge construction and other fields。The following is aboutS355JRDetailed knowledge of square tubes：

Property

chemical composition：

carbon (C)：≤0.24%

silicon (Si)：≤0.55%

manganese (Mn)：≤1.60%

phosphorus (P)：≤0.035%

sulfur (S)：≤0.035%

nickel (Ni)：≤0.012%

copper (Cu)：≤0.55% This combination of ingredients gives it high strength, good weldability, and formability。

mechanical property：

yield strength：Thickness less than16mmtime，The minimum yield strength is355MPa；Thickness in250-400mmtime，The yield strength decreases to265MPa。

tensile strength：The scope is450-680MPa。

impact toughness：The minimum impact energy at room temperature is27Joule。

Elongation rate：The fracture elongation is approximately20%，Has good extensibility。

Production process

S355JRThe production of square tubes includes raw material preparation、forming、welding、align、slicing、Inspection and packaging steps。Usually using high-qualityS355JRSteel plate or strip，After precision cutting and pre-processing, it is sent to the forming unit。During the molding process，Gradually bend the steel plate into the desired square cross-section through a series of molds，Subsequently, high-frequency welding or submerged arc welding is performed，Ensure the strength and sealing of the weld seam。After welding is completed，The pipe material needs to be straightened to eliminate welding stress，Ensure its straightness and dimensional accuracy。

application area

building structure：Used for beams and columns in steel structure buildings、support structure，Can effectively support large-span spaces，Improve the overall safety and durability of buildings。

Machinery manufacturing：Used for manufacturing heavy machinery、Vehicle manufacturing、Frame for agricultural equipment and other fields、Support frame、Key components such as transmission shaft。

bridge construction：Due to its excellent fatigue resistance and weldability，Becoming an indispensable component in bridge structures，Like bridge piers、Bridge deck support system, etc。

Furniture manufacturing：Widely used in office furniture、In the design of outdoor leisure furniture，Due to its simple lines and good load-bearing capacity。

automobile making：Under the trend of new energy vehicles and lightweight design，S355JRSquare tube due to its high strength and low density characteristics，Becoming an important material for body structural components。