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Stainless steel tube wall thickness eccentricity generated by the causes and factors affecting what?

Stainless steel tube wall thickness eccentricity generated by the causes and factors affecting what?

Time:2022-03-17 Source:China Wuxi JiaNuo Special Steel Co.

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The most common defect of stainless steel pipe is the uneven wall thickness of the pipe, the minimum deviation of the average wall thickness and the relationship between the pipe-making process: rolling machine and reducing tensioner, stainless steel pipe billet for example, in: perforating machine, the wall thickness deviation of the capillary tube is at least 7.5%, after stretching and rolling reduced to 4.5%, increased to 7% expansion, the diameter is reduced, and then reduced to 4.5%.

Stainless steel pipe eccentric wall thickness on the strength of the steel pipe and cold processing a series of adverse effects, thus affecting the economic efficiency. When rolling large-diameter thick-walled stainless steel pipe, the local depression rate increases, leading to cracks and mechanical failures in the mill.

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1.1 Cross-rolling punching

In the cross-rolling and perforating process, the billet rotates as it advances, producing a spiral wall thickness eccentricity in the perforated capillary tube. Perforated capillary tube wall thickness distribution is complex, with multiple fluctuations of different magnitudes and different cycles. Wall thickness deviation curve, following the Fourier analysis of the wall thickness distribution, inferring the stainless steel tube wall thickness eccentricity coefficient.

According to the analysis of each period, the stainless steel tube wall thickness eccentricity is mainly caused by the following factors.

(1) the temperature of the blank section.

(2) saw head vibration (the center of the saw head does not coincide with the center of the saw bar).

1.2 Stainless steel pipe wall thickness eccentricity caused by the temperature difference in the rough section

If the rough section has temperature unevenness, the circumferential resistance to deformation is poor, the left and right pressure imbalance.

According to this calculation method, the wall thickness eccentricity caused by the temperature difference of the rough part is 1.7%, corresponding to the temperature difference condition of 20.

1.3 Head vibration caused by the head accuracy and eccentricity

I plant small batch stainless steel pipe billet capillary inspection is in: when the center of the head is misaligned or not round, capillary tube size of 1368mm, the use of the maximum eccentricity of 1.5mm capillary tube capillary inspection with non-eccentric head compared to the plug accuracy caused by wall thickness eccentricity up to 0.30.8mm, which can be concluded that the plug accuracy has a greater impact on the eccentricity. Even if the stainless steel tube wall thickness is uniform, the resistance to deformation is not good, so the peripheral wall thickness is not uniform.