First, the cutting oxygen pressure is too high

B, improper choice of cutting mouth

C, cutting speed is too fast

D, preheating flame energy is too large

2, steel plate cutting process:

A, in automatic cutting, the steel plate is hoisted to the gas cutting platform, and the distance difference between the two ends of the steel plate and the guide rail should be adjusted within 5 mm In semi-automatic cutting, the guide rail should be placed on the plane where the steel plate is cut, and then the cutting machine should be lightly placed on the guide rail. Face the side with the cutting torch to the operator, select the cutting nozzle according to the thickness of the steel plate, and adjust the cutting straightness and cutting speed.

B, according to the difference between automatic cutting and semi-automatic cutting, adjust the distance of each cutting gun, determine the tailing amount, and consider kerf compensation; In the cutting process, the size and direction of the tilt angle of the cutting gun mainly depend on the thickness of the steel plate.

C, according to the thickness of the plate, adjust the cutting parameters, including the model of cutting nozzle, oxygen pressure, cutting speed and preheating flame energy. The selection of process parameters is mainly based on the type of gas cutting machinery and the thickness of steel plate that can be cut. For uncut steel plates, try to cut similar steel plates, determine cutting parameters and check the gas patency of cutting nozzles.

D, before gas cutting, remove the dirt and grease on the steel surface, leaving a certain space below to facilitate slag blowing. During gas cutting, the cutting torch should move at a uniform speed, and the distance between the surface of the cutting blade and the tip of the flame core is 2 ~ 5 mm If the distance is too close, the edge of the incision will melt, and if the distance is too far, the heat will be insufficient, which will easily interrupt the cutting.

E, when cutting thick plates, the preheating flame should be large, and the length of gas cutting flow should exceed 1/3 of the workpiece thickness. The included angle between the cutting nozzle and the workpiece surface is about10 ~ 20, so that the edge of the part is heated evenly. Whether using multi-head straight bar and numerical control cutting to cut the main material or semi-automatic cutting to process small parts and grooves, local gaps with a depth of more than 1mm and kerfs with a depth of more than 0.2mm should be welded and polished smoothly.