What should be considered when bending hot-rolled steel coil pipe?

　　Processing and manufacturing thick-walled components Steel plate rolled pipe At this stage, the rolling‑bearing pins and locating pins of the two upright columns serve as precision positioning references. It is crucial to ensure that the upper or lower load‑bearing beam is securely fastened to the left or right upright column using high‑strength bolts, forming a single integral unit. During fabrication, attention must be paid to the precise fit between the rolling‑bearing pins and their corresponding pin holes in the steel‑plate rolled pipe. Installation should also clearly identify the mating marks. Throughout the entire manufacturing process of the steel‑plate rolled pipe, since the four guide rails come in two distinct specifications and exhibit substantial differences in overall width, four guide rails must be mounted on the inner wall of the sound‑card frame: the two wider ones should be positioned near the drive‑system side, while the narrower ones should be installed closer to the main motor side.
 

　　It should be noted that the flatness of the main structure must be verified using a level, with a tolerance of 2 mm per meter. After the sound card rack is securely installed, use a torque wrench to tighten the high-strength bolt assembly to a tightening torque of 750 N·m. Subsequently, during the fabrication of Q345B steel plate‑rolled pipes, once the anchor bolts connecting to the rack have been tightened, ensure there is no gap between the column’s welded surface and the load‑bearing beam; the steel plate‑rolled pipes should then be mounted on the rack without delay.

　　It should also be noted that, during the fabrication of steel plate‑rolled pipes, the main frame must be hoisted into its designated installation position. Importantly, only the lifting holes in the lower load‑bearing beams may be used to avoid bearing loads from the anchor bolts connecting to the frame. Furthermore, based on the fabrication process design drawings, it is essential to verify and adjust both the elevation of the main structure and its design elevation, as well as the relative positioning between the main structure and the two main motors.

　　Steel plate rolled pipes have a wide range of applications, currently focusing on industries such as hardware tools, automotive components, standard parts, mechanical equipment manufacturing, textile machinery, elevator guide rails, transformers, and other sectors of the machinery manufacturing industry.

　　The key points that must be observed throughout the entire bending process of hot-rolled steel coil pipe include the following aspects:
 

　　1. When processing hot-rolled steel coil pipe, the thicker the material’s specification, the wider the sheet‑metal bending range required; moreover, as the thickness of the hot‑rolled steel coil pipe increases, the bending equipment selected should also accommodate a larger bending range.

　　2. Under the standards for hot-rolled steel coil processing, as the compressive strength of the sheet increases, its tensile strength decreases; consequently, the required bending range of the sheet becomes wider, and the bending angle also increases.

　　3. If the thickness of the hot-rolled steel coil pipe matches the sheet‑metal bend thickness specified in the design drawings, then, based on industry experience, the dimensions of a bent‑part workpiece should be calculated as the right‑angle leg length minus twice the material thickness. This approach ensures adequate allowance for precision adjustments in the design.

　　4. If the tensile strength of hot-rolled steel coil material is higher, its ductility will also be greater; accordingly, if a 90-degree bend can be achieved in sheet metal bending, the required die‑opening angle in the design should be smaller.