Steel Plates Cutting Process with CNC Flame Cutting Machine

1. After the gas cutting is completed, the cut surface of the steel should be inspected. The cutting surface should be free from cracks, slag inclusions and ribs larger than 1 mm. The inspection method is visual inspection.

2. After the gas cutting is completed, the project name, part number and the assigned team should be indicated on the cutting piece.

Cutting operation process:

When performing automatic cutting, the distance between the two ends of the steel plate and the guide rail should be adjusted within 5mm from the hanging steel plate to the gas cutting platform. When performing semi-automatic cutting, the guide rail should be placed on the plane of the cut steel plate, and then the cutter should be lightly placed on the guide rail. The side with the torch is oriented to the operator, and the cutting tip is selected according to the thickness of the steel plate to adjust the cutting straightness and the cutting speed.

Steel plate cutting process

1. Scope: This standard applies to the processing of raw material cutting and cutting. It is suitable for the cutting and cutting process with flame cutting and plasma cutting as the cutting method.

2. Construction preparation:

2.1 Material requirements:

2.1.1 The steel plate used for cutting and cutting should be inspected and accepted by the quality department, and its various indicators meet the corresponding provisions of the national regulations.

2.1.2 The steel plate shall be inspected for the grade, thickness and surface quality of the steel plate before cutting. For example, the surface of the steel surface where the depth of the corrosion point exceeds the negative deviation of the national standard steel plate is not allowed to be used for the product. A small area of pitting can be polished to the pass without shrinking the design thickness.

2.1.3 When the material is to be cut, the grade, specification and surface quality of the steel plate must be checked. After confirmation, the material can be cut.

2.2 Construction equipment and tools:

2.2.1 Cutting and cutting equipment mainly includes CNC flame cutting machine, CNC plasma cutting machine, straight cutting machine and semi-automatic cutting machine.

2.2.2 Before the gas cutting, first check that the equipment and tools of the entire gas cutting system are all operating normally, and that it can be operated under safe conditions, and should be kept in the process of gas cutting.

2.2.3 Detection and identification tools are: steel ruler, tape measure, stone pen, marker pen, etc.

3. Cutting operation process:

3.1 When performing automatic cutting, the distance between the two ends of the steel plate and the guide rail should be adjusted within 5mm from the hanging steel plate to the gas cutting platform. When performing semi-automatic cutting, the guide rail should be placed on the plane of the cut steel plate, and then the cutter should be lightly placed on the guide rail. The side with the torch is oriented to the operator, and the cutting tip is selected according to the thickness of the steel plate to adjust the cutting straightness and the cutting speed.

3.2 According to the different automatic cutting and semi-automatic cutting methods, adjust the distance of each cutting torch, determine the rear drag, and consider the kerf compensation; during the cutting process, the size and direction of the cutting angle of the cutting torch are mainly determined by the thickness of the steel plate. The relationship between the nozzle inclination angle and the thickness of the cutting piece and the cutting allowance are shown in the following table:

        Relationship between the inclination of the cutting nozzle and the thickness of the cutting piece

Cutting thickness <10 ≥10

Inclination direction

Tilt angle 10°-15° 0°

Cutting method Material thickness mm Slot width allowance (mm) Remarks

Gas cutting and cutting ≤10 1~2

10~20 2.5

20~40 3.0

40 or more 4.0

When performing thick plate gas cutting, the cutting nozzle is perpendicular to the surface of the workpiece. After the entire section is cut through, the cutting nozzle is moved and transferred to normal gas cutting. When the gas cutting is to reach the end point, the slow speed should be slightly increased, so that the lower part of the cutting is completely cut.

3.3 Adjust the cutting parameters according to the thickness of the plate. The cutting parameters include the cutting nozzle type, oxygen pressure, cutting speed and energy of the preheating flame. The selection of the process parameters is mainly based on the type of gas cutting machine and the thickness of the cuttable steel plate. Steel plate, test the same type of steel plate, determine the cutting parameters, and check the gas patency of the cutting nozzle.

3.4 Remove the dirt and grease on the surface of the steel before the gas cutting, and leave a certain space below to facilitate the blowing of the slag. When cutting gas, the movement of the torch should be kept at a constant speed. The surface of the cutting piece should be 2~5mm away from the tip of the flame. If the distance is too close, the edge of the cutting will melt, too much heat is too low, and the cutting is interrupted.

3.5 When performing thick plate cutting, the preheating flame is large, and the length of the gas cutting airflow exceeds 1/3 of the thickness of the workpiece. The cutting tip is inclined at an angle of 10° to 20° to the surface of the workpiece to uniformly heat the edge of the part.

3.6 In order to prevent gas cutting deformation, the following aspects should be noted during the operation:

3.6.1 When cutting workpieces of different sizes on the steel plate, the small pieces should be cut first and then cut into large pieces;

3.6.2 Cutting of narrow strips, leaving 50mm at both ends without cutting, cutting after long edges are cut, or using a symmetrical cutting method with multiple torches.

3.6.3 When cutting straight strips, it should be noted that the flame strength of each cutting tip should be consistent, otherwise it will easily produce side bends.