How to do the cutting work of extra heavy S355J2 plate

In thick S355J2 plate cutting, the temperature descends from the top surface downward. At the beginning of cutting, the oxygen pressure gradually increased, and the thickness of the S355J2 plate reached the same direction. This results in inconsistent combustion in the thickness direction of the S355J2 plate at the beginning of cutting, and defects at the beginning of cutting. To avoid defects, the following methods can be adopted:

1, use circular feed to increase the length of the leading line to avoid direct entry point. This method has good effect and is widely used in production. Its disadvantage is waste of S355J2 plate materials.

2, the use of ignition rod. The method is to add a piece of S355J2 plate to the thickness of the S355J2 plate at the cut-in point, and there should be no crack at the close place. The cutter should cut through the ignition rod. The ignition rod will guide the cutting moment flame to the bottom of the S355J2 plate, so that the burning speed of the S355J2 plate can reach the same level and the best cutting section can be obtained. The ignition rod can be replaced by cutting leftover material. This method reduces the distance between the workpiece and the edge of the plate, reduces the generation of corner surplus, and effectively improves the utilization ratio of the plate. The ignition rod is more practical in cutting extra heavy S355J2 plate.