Analysis of the main reasons for the decline in the quality of steel bending pipe and precautions. During pure bending, the outer arm wall of the neutral layer of the steel pipe is thinned by the tensile stress &1 under the action of the external force M, and the inner side is subjected to compressive stress. The action thickens, and the forces N1 and N2 change the cross-section of the steel pipe. Based on this factor, the main reason for the decline in the quality of steel bending pipe is RX and SX. Therefore, in GBJ235-82, the RX value and the thinning amount of the outer side under various pressure levels are clearly defined, in order to control the values of RX and SX, so as to ensure quality.
When steel bending pipes, the outer side of the material is tensile, and the position of the neutral axis of the inner side of the steel pipe is different from the steel bending pipe method. When working in the top bending (compression bending), the neutral axis is about 1/3 away from the outer wall, and when working in the rotation bending (return bending), the neutral axis is 2/3 away from the outer wall. Therefore, it is beneficial to use the rotation bending method for thin-walled pipe bending.
The bending accuracy is also one of the factors that affect the quality of steel bending pipe.
The bending performance and surface corrosion of the pipe itself may also affect the quality of steel bending pipe. During on-site construction, the operator also needs to understand the material of the pipe being processed, the processing performance, and the surface corrosion to make production judgments.
Post time: Apr-14-2025