Spiral steel pipe has beautiful surface and diversified use possibilities, good corrosion resistance, long-lasting durability of ordinary steel. The spiral steel pipe has high corrosion resistance and high strength. Therefore, the thin plate has high possibility of use, high temperature oxidation resistance and high strength, so it can resist fire at normal temperature. Processing, that is, easy plastic processing. So what are the characteristics of bending a spiral steel pipe? Let’s take a look at it together.
The main difference between the chemical composition of 316 and 304 is that 316 contains Mo, and it is generally accepted that 316 has better corrosion resistance and is more resistant to corrosion than 304 in high temperature environment. Therefore, in high temperature environments, engineers generally use parts of 316 materials. But the so-called thing is absolutely no, in the concentrated sulfuric acid environment, do not use 316 for high temperature, we know that in order to prevent the thread from seizing at high temperature, a dark solid lubricant needs to be applied.
Because of the high yield point and high hardness of 304 stainless steel, the effect of cold work hardening is remarkable. The characteristics of spiral steel pipe when bending are as follows: because the thermal conductivity is worse than ordinary low carbon steel, the elongation is low, resulting in large deformation force; stainless steel plate The material has a strong tendency to rebound compared with carbon steel during bending; the stainless steel plate has a lower elongation than the carbon steel, and the bending angle R of the workpiece is larger than that of carbon steel when bending, otherwise there is a possibility of cracking; The hardness of the steel pipe is high, and the cold work hardening effect is remarkable.
Therefore, when selecting the bending tool, the tool steel with heat treatment hardness of 60HRC or more should be selected, and the surface roughness should be one order of magnitude higher than that of the carbon steel bending tool.
According to the above characteristics, in general, the thicker the sheet, the greater the bending force required, and the margin of bending force should be larger when the bending equipment is selected as the unit thickness increases; The greater the tensile strength, the smaller the elongation, and the greater the bending force required, the larger the bending angle should be.
According to the actual situation, the unfolding size of a curved workpiece is two angles plus and minus two plate thicknesses, which can fully meet the design accuracy requirements. Calculating the expansion amount according to the empirical formula can simplify the calculation process and greatly improve the production efficiency; the yield strength of the material is larger. The greater the amount of elastic recovery, the smaller the angle of the required pressing knife is to obtain the angle of 90 degrees of the bending member. Compared with the same thickness of carbon steel, the spiral steel pipe has a large bending angle.
This point should pay special attention to the occurrence of crushing cracks and affect the strength of the workpiece. It is not immediately generated when the pull-off member is retracted from the convex mold, and sometimes it is not cooked when the deep-drawing deformation is first hit or vibrated; sometimes it is firstly stored in a deep time or in the application. It only happens in the process.
The above is the characteristics of the bending process of the spiral steel pipe. In general, because it does not need surface treatment, it is simple and easy to maintain. Clean, high finish. Good welding performance.