Plasma Cutting Machine Using Method
1. The Plasma cutting machine switch is close to the gun head. If the machine works continuously for a long time, the heat generated by the flame often burns the hand holding the gun head, and the splashing molten iron can easily burn the hand. If the switch of the plasma cutting machine gun head is led to the back, away from the gun head, it will not be easy to burn the hand during the operation.
2. If the cutting gun is improved to reduce the burning sensation of the operator, a removable heat insulation baffle can be installed on the gun head porcelain sleeve, such as ceramic material, between the gun head and the operating gloves
3. If the gun head is changed to a more pointed one, the angle formed by the flame will be smaller and it can be pressed lower; after the flame forms a certain angle, if it is pressed too low, it is easy to damage the hull steel plate when the flame passes through, and if it is pulled from the middle, the flame will just not damage the hull. If the plasma gun head is made smaller, this method will be more efficient, similar to the size of a gas cutting gun.
4. Features and precautions for using plasma cutting machines
1. The method of blowing the weld can minimize the welding residue, which is similar to cleaning the deck with an air planer, and you can experience the feeling of cutting iron like mud.
2. However, the disadvantage is that the operator is exposed to strong ultraviolet rays and thermal radiation. If the blowing time is long, it is easy to melt the plastic parts on the cutting gun. The operator’s hands holding the cutting gun will feel unbearable with thick gloves. Cutting
3. When cutting, the distance between the arc and the weld is kept at 2mm-4mm. Direct contact with the workpiece is easy to burn the nozzle.
4. During operation, the length of the arc changes frequently, which is easy to burn the tungsten electrode and shorten the life of the tungsten electrode. Frequent inspection is required.
5. Application case of plasma cutting machine
For a certain wheel-mounted wind power equipment, the binding reinforcement of the wind power main engine is completely fixed by the stopper, and the thickness of the stopper is far beyond the penetration ability of plasma.
When unloading, because the cutting personnel did not understand the method of blowing the weld, they adopted direct lifting and unloading without cutting the stopper. However, the center of gravity of the wind turbine main engine cargo is irregular, and the hook head needs to be slowly centered during the unloading process in order to ensure that the four sides of the cargo are off the bottom at the same time, so as to get rid of the restraint of the stopper. However, the process of locating the hook head in this way takes a long time to unload a piece of cargo. If the method of blowing the weld is adopted, the stopper is cut off before unloading, which can not only ensure the safety of unloading, but also avoid unnecessary waste of time.
VI. Experience summary
I) The cutting and welding technique mainly depends on the ability to control the flame. If the method is not correct, it is easy to damage the hull steel plate, and it is even very likely to cut through the bypass and the bottom plate of the cabin. Use the correct method, practice diligently, and summarize and improve at the same time.
II) When cutting and welding, molten iron is easy to splash and hurt the operator himself. Measures should be taken to avoid it, such as opening a window, cutting and welding techniques, or choosing handy tools.
III) The method of blowing the weld takes a little longer, and the operator must be careful and patient.
4) After the stopper is cut off, the height of the weld pile should be controlled at 3 +/- 2mm, that is, 1 to 5mm, and it cannot be a negative height (damaging the deck).
VII. Cutting and welding methods
I) The first method “cutting the body”
When using a Plasma cutting machine to cut the stopper, choose to start the knife above the weld and cut the stopper body. The advantages of this method are: simple, direct, and not easy to damage the hull. Disadvantages: The cut stopper often leaves a very high pile, and it needs to be blown flat twice in the later stage. The grinding workload is also relatively large, wasting manpower, material resources and time.
II) The second method “blowing the weld”
In layman’s terms, it is a method of blowing away the “weld body”. That is, the plasma gun head is close to the deck, starting from the weld until a gap is exposed between the stopper and the weld body. The air pressure and current are slightly smaller than the air pressure and current during cutting, so that the flame and the weld are at an angle of about 45 to 70 degrees and kept moving on the weld to allow the molten iron to flow away. If you feel that the weld is too high during the operation, press the flame down a little, but always keep the flame on the weld so that it will not damage the hull. Two-knife cutting, that is, blowing one side first, then blowing the other side, and then tapping it gently with a large hammer, the stopper is basically cut off, and at the same time, a large amount of residue is attached to the cut stopper, the cutting effect is good, and the later grinding workload is still small. This method requires high cutting technology for personnel, because problems are not easy to be discovered during cutting.
VIII. Specific example—H-beam cutting skills
I) Characteristics of H-beam stoppers
1. H-beam is common and used in large quantities. It is a commonly used stopper in the lashing and reinforcement of major ship parts.
2. The operating space is often narrow and difficult to cut. The way of cutting affects the cutting effect. Operators often cut above the weld, leaving high pile stubble.
3. When cutting H-beam, molten iron is prone to splashing back and scalding the operator himself.
II) Methods for cutting H-beam
1. First, make the process holes. Make holes at the four inner corners of the H-beam. The advantage is that the molten iron has a place to flow, so it is not easy to splash back and hurt people.
IX. Tips for using plasma cutting machine
I) Pay attention to air pressure
High air pressure and short flame will cut deeper, and the deck will be damaged if you are not careful. Low pressure will cut slower and it is not easy to cut through. Adjust the air pressure according to the thickness of the weld (usually kept at 0.45-0.60MPa)
II) Adjust the angle of the gun head, and the direction and length of the flame.
When cutting, pay attention to the height of the flame blowing through the workpiece. The angle formed by the gun head and the deck affects the height of the residual weld. Affected by the diameter of the gun head, this angle of 5° to 15° is more appropriate. Pay close attention to the direction and length of the flame during the cutting process. If the flame airflow is not concentrated, the penetration ability is reduced, and the nozzle has a gap, the power should be turned off in time, the nozzle should be replaced to check the tungsten electrode, and when the center of the tungsten electrode is concave by more than 2mm, it should be replaced in time.
3) Modify the plasma gun
“If you want to do your work well, you must first sharpen your tools.” Modify the plasma cutting gun head, lengthen the handle, and move the switch away from the gun head.
Plasma cutting machine occupy an important position in the field of metal processing with their advantages such as high speed, high precision, high quality, wide applicability, large cutting thickness, simple operation, low cost and environmental protection.