Cylinder unrolled length (elongation rate)
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The unfolded length of a typical cylinder is the diameter of the cylinder multiplied by 3.1415926. On http://zhidao.baidu.com/question/105159657.html?si=6, several posts discuss the unfolding of cylinders. I would appreciate any insights from experts. The first viewpoint is that the length can be calculated using the following formula: L = πDp + δ1 + δ2 + δ3, where L represents the length of the steel plate needed for the cylinder, in mm； Dp — average diameter of the cylinder, mm ； δ1 — gas cutting allowance, mm ； δ2 — Machining allowance, mm ； δ3 — excess length of the pre-bent straight section, mm. The second viewpoint is to take the length resulting from the actual diameter of the cylinder (inner diameter + wall thickness) and add the amount of shrinkage due to welding; leaving a margin of about 3 mm for each A weld. For a device with a length of 600 mm, there is likely only one such A weld. It can be calculated as (600+6)*3.1415926+3; the extension associated with ordinary rounding needs to be considered almost none of the time.
I would like to ask the experts another question: what are the inspection standards for finished cylinder products? 1. Measure the circumference of the cylinder; 2. Measure the diameter of the cylinder
We also need to check the edge deviation of the cylinder body, the corner angles, and then the out-of-roundness
Previously, it was sufficient to calculate based on the mean diameter. But for some reason lately, the material stretches during cold rolling: smaller diameters stretch more, while larger diameters stretch less; in some cases, the stretching amount can exceed 20 mm, forcing a second cutting step.