S355JRSquare tube is a non alloy structural steel square tube that meets European standards，Has high strength、Good toughness and weldability，Widely used in architecture、Machinery manufacturing、Bridge construction and other fields。The following is aboutS355JRDetailed introduction of square tube：
Material characteristics
yield strength：S355JRThe minimum yield strength is355MPa。
tensile strength：The range of tensile strength is470-630MPa。
impact toughness：at room temperature（20℃）Has good impact toughness。
weldability：Has good weldability，Suitable for various welding processes。
corrosion resistance：Corrosion resistance can be enhanced by surface galvanizing or painting treatment。
Production process
S355JRThe production of square tubes mainly includes the following steps：
raw material preparation：Adopting high-qualityS355JRSteel plate or strip。
forming：Bend the steel plate into a square or rectangular cross-section through a mold。
welding：Using high-frequency welding or submerged arc welding，Ensure weld strength and sealing。
align：Eliminate welding stress，Ensure straightness and dimensional accuracy。
Cutting and Inspection：Cut to size according to customer requirements，And conduct a visual inspection、Mechanical performance testing and non-destructive testing。
Dimensions and specifications
Wall thickness deviation：When the wall thickness is not greater than10mmtime，The allowable deviation is the positive or negative of the nominal wall thickness10%；Wall thickness greater than10mmtime，Allowable deviation is positive or negative8%。
Delivery length：Usually it is4000mm-12000mm，use6000mmand12000mmbe in the majority。
Curvature：The curvature per meter shall not exceed2mm，The total curvature shall not exceed the total length0.2%。
application area
building structure：Used for beams and columns、Supporting structures, etc，Can effectively support large-span spaces。
Machinery manufacturing：Used for manufacturing frames、Key components such as support frames。
bridge construction：Due to its fatigue resistance and weldability，Suitable for bridge piers、Bridge deck support system。
Furniture manufacturing：Used for office furniture、outdoor leisure furniture。
automobile making：In the field of new energy vehicles and lightweight design，Used for body structural components。
Selection precautions
dimensional accuracy：Select appropriate cross-sectional dimensions and wall thickness based on specific application requirements。
Surface Treatment：Choose the appropriate surface treatment process based on the usage environment。
mechanical property：Evaluate the mechanical properties of pipes based on design loads and working environments。
weldability：Pay attention to the selection of welding parameters and the control of welding processes。
Cost effectiveness：Taking into account material costs comprehensively、Processing and transportation costs。
S355JRSquare tube due to its excellent performance and wide range of applications，Has become an indispensable material in modern industry and architecture。
