Straightening can improve the residual stress distribution in the cutting process of punching C-section steel and the zero cutting of formwork. When the stress distribution of the steel plate section is uneven, roll bending measures can be taken to add deformation to compensate for the uneven longitudinal fiber length, and then eliminate it. Wavy bending makes the internal stress of punched C-section steel uniform. The adjustment of horizontal crown value of straightener is also an important measure to improve the residual stress distribution of C-section steel.
The cutting speed of fiber laser cutting machine can properly improve the cutting quality, that is, the cutting is slightly narrow, the cutting surface is lubricated and the deformation is reduced. The cutting speed is too fast, so the cutting line energy is less than the required value. The jet at the cutting seam of punching C-section steel can not blow away the molten cutting melt, forming a lot of subsequent resistance. When cutting C - cast steel, the quality of the cutting surface decreases. When the speed is high, even the arc subsides because the cutting is too wide. It can be seen that the excellent cutting quality is inseparable from the cutting speed.
When the cutting speed is too low, because the cutting part is the sun of the plasma arc, in order to maintain the stability of the arc itself, it is necessary to find the driving current arc close to the slit in the solar speckle or solar area, and it will flow into the jet together. More heat is transferred radially to widen the cut-off. The melts on both sides of the cut-off gather and condense at the lower edge to form molten slag that is not easy to be fixed. The upper edge of the cut-off is heated and melted to form a fillet.
The internal stress imbalance caused by shear laminar cooling of punched C-section steel is mainly caused by three kinds of uneven cooling, resulting in very uneven transverse cooling. Asymmetric cooling in thickness direction. Uneven thickness and side cooling mixture. Manipulate the transverse uniformity and cooling symmetry in the thickness direction to control the flatness of the plate and reduce the internal stress of the plate. Improved side cooling and side spraying plans with lower nozzles. Select the side angle and static water point to complete the uniformity of laminar cooling temperature control.