Views:90 Author:Ronsco Publish Time: 2021-05-12 Origin:Ronsco
In the daily processing of stainless steel pipes, it is often necessary to cut. There are different cutting requirements for different processing. Different cutting processing methods have different costs and expenses. Now Ronsco will introduce 9 common cutting processing methods.
This new technology uses a 0.80 to 1.50 mm jet of water, with a jet velocity of 600 to 800 meters per second (velocity greater than Mach 2). The water pressure is 3000-4000 bar (bar), and the water consumption is only 4 liters per minute.
In order to cut stainless steel with abrasives such as alumina or silicon carbide, before the jet of water reaches the steel, abrasive particles are injected into the water. Modern equipment can cut 20.0mm thick stainless steel. The cutting edge is accurate, and the cutting surface is clean and smooth.
The heat generated by the cutting action is taken away by the water, and the metal temperature is only 50-60°C. This, coupled with the force generated by the jet of water on the metal, can prevent deformation and improve cutting accuracy.
This process uses circular and triangular punches to punch out a series of overlapping holes. Obviously, this process cannot make the cut very smooth, but by adopting a good tool design and overlapping the cuts, the cutting edge can meet the requirements of most applications. Portable stepper punching machine is usually used for cutting carbon steel sheet, if used to cut austenitic stainless steel, it needs to increase the force by 60%. Also, reduce the maximum thickness of the machine cutting. The machine in the processing plant can punch at least 8mm stainless steel. Modern machines can also use the combination of shear and punch to produce the required blanks.
Most processing plants use this kind of hand operated shears. The blade length of this shearing machine can reach 3m, but if the end of the shearing machine is open, continuous shearing can be used to obtain a cut longer than the shearing blade. But be careful not to cut out the steps.
Due to the high power required for cutting stainless steel, the thickness that the shearing machine can cut when cutting soft steel is reduced by two wire gauges when cutting ferritic steel, and when cutting austenitic stainless steel To reduce 4 wire gauge numbers. Therefore, a shear that can cut soft steel up to 2mm should be reduced to less than 1.6mm and less than 1.2mm for austenitic steel when cutting ferritic steel, and the shearing blade gap needs to be reduced accordingly. The typical shear blade gap value for bulk stainless steel is 5%.
Most processing plants know the importance of holding the steel plate firmly and keeping the blade in good condition during the cutting processing. However, those who are new to stainless steel may not know that in order to prevent contamination of the stainless steel surface, they need to work on a guillotine shear. Place protective pads on the table or other places in contact with carbon steel. If the guillotine shear also cuts carbon steel, it is best to check the blade before cutting stainless steel to remove carbon steel particles that may adhere to and contaminate the stainless steel.
The basic working principle of disc shears is the same as that of guillotine shears, but continuous cutting can be carried out by using disc blades. The steel plant uses several blades on two shafts to slit wide steel coils. However, a pair of blades can also be used to cut single straight strips. Some shears can also move the blade to one side to cut the wedge-shaped blank during the cutting processing, while others can rotate the knife to cut the round blank.
Although bow saws and band saws can be used to cut thin and narrow plates, these two types of saws are usually used to cut medium and thick plates, sections and pipes.
Austenitic stainless steel is hardened by cold work, and friction is strictly prohibited. This is very important and must be paid attention to. Therefore, the saw must be lifted during the return stroke of the saw. The high-speed tool steel saw blade has 8 to 10 teeth per inch when sawing thick materials, and 24 to 32 teeth per inch when sawing thin plates and pipes. When cutting austenitic stainless steel by motor, it cuts 50/80 times per minute. When ferritic stainless steel is sawed 100/200 times per minute. When cutting on a conventional band saw, use sharp saw teeth at low speed and uniform small feed to keep the saw blade cutting.
This method uses a high-speed rotating grinding wheel to cut steel. The grinding wheel is made by bonding abrasive materials with fiber, resin or rubber. In skilled manual operation, the grinding wheel can cut quickly and accurately, and the cut is neat and free of burrs. The grinding wheel can only be used for straight cutting, but this is sufficient for most applications.
Grinding wheels are usually used to cut pipes. Processing plants also use grinding wheels to grind long grooves.
On-site repairs usually use hand-operated grinders. However, the use of hand-operated grinders produces a large amount of dust and "steel chips, so dust removal or protection devices are required. The grinders used in the production plant are generally equipped with cooling systems, which can reduce dust and prevent damage to materials. Cause heat damage.
This technology uses the energy released when a laser beam is irradiated on the surface of the steel plate to melt and evaporate stainless steel. The laser source generally uses a carbon dioxide laser beam with a working power of 500 to 2500 watts. The power level is lower than that required by many household electric heaters, but the laser beam is concentrated in a small area through lenses and mirrors. The high concentration of energy enables rapid local heating to evaporate stainless steel. In addition, because the energy is very concentrated, only a small amount of heat is transferred to other parts of the steel, resulting in little or no deformation. The use of laser can cut blanks of complex shapes very accurately, and the cut blanks do not need to be further processed.
The use of laser cutting equipment can cut stainless steel below 4mm, and oxygen can cut 8-10mm thick stainless steel in the laser beam, but after oxygen cutting, a thin oxide film will be formed on the cutting surface. The maximum thickness of the cut can be increased to 16mm, but the size error of the cut part is relatively large.
The price of laser cutting equipment is quite expensive, about 150 dollars or more. However, because the cost of subsequent processing is reduced, it is feasible to use this equipment in mass production. Since there is no tool processing cost, laser cutting equipment is also suitable for the production of small batches of parts of various sizes that could not be processed previously. At present, laser cutting equipment usually uses computerized digital control technology (CNC) devices. After using this device, you can use telephone lines to receive cutting data from computer-aided design (CAD) workstations.
This method is to pass the mixed gas through a high-frequency arc. The gas can be air or a mixed gas of hydrogen, argon and nitrogen. The high-frequency arc "decomposes" or ionizes some gases into basic atomic particles, thereby generating "plasma". Then, the arc jumps to the stainless steel workpiece, and the high-pressure gas blows the plasma out of the torch burner with an exit velocity of 800-1000 meters per second (about Mach 3). In this way, combined with the high energy released when the various gases in the plasma return to a normal state, a high temperature of 2700°C is generated. This temperature is almost twice the melting point of stainless steel. So that the stainless steel melts quickly, and the molten metal is blown away by the jet of high-pressure airflow. Therefore, it is necessary to use smoke and slag removal equipment.
This method can be used to cut stainless steel with a thickness of 3.0 to 80.0 mm. The cut surface is oxidized, and due to the characteristics of the plasma, the cut is in a figure eight shape.
Using a conventional manual shearing machine, if the cutting edge is sharp, you can cut stainless steel below 0.9mm. However, due to the short cut length of each cut, the steel plate is easy to curl during the cutting process, and the quality of the cut edges is poor. Unless the requirements for the appearance of the trimming are not high or the uneven trimming does not hinder the next process (such as difficult to align the welds, etc.), manual shears are not recommended for cutting.