Analysis of the main reasons for the decline in the quality of steel bending pipes

Analysis of the main reasons for the decline in the quality of steel bending pipes and how to pay attention. In pure bending, under the action of external force distance M, the outer arm wall of the neutral layer of the tube is thinned by tensile stress &1, and the inner side is subjected to compressive stress. Thickening due to the action of N1 and N2 to change the cross-section of the tube. 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 demarcated. The purpose is to To control the value of RX and SX, to ensure quality.

When the steel bending pipe is in tension on the outside of the material, the position of the neutral axis under pressure on the inside of the steel bending pipe is different from that of the steel bending pipe. In the top bending (compression bending) operation, the neutral axis is away from the outer wall At about 1/3, the neutral axis is 2/3 away from the outer wall when it is working in a swivel (return bend). Therefore, when thin-walled pipes are bent, it is beneficial to use the swivel method.

The precision of the bent tire is also a factor affecting the quality of the steel bending pipe.
The bendability and surface erosion of the pipe itself may also affect the quality of the steel bending pipe. During on-site construction, the operator also needs to understand the material of the processed pipe, and the processing function and make production judgments on the surface erosion.