Polishing And Milling Methods And Decisive Factors Of Stainless Steel Elbow Pipe Fittings
When milling stainless steel elbows, the compromise between milling rate and service time is the decisive factor affecting economy. In one test, the steel bag received fifteen wet feeds and then ten dry millings. During the long-term operation, the knife tuber and slight free surface wear will occur, so all steel bags should be wet processed in the future. Then use a profile milling cutter with a diameter of 81 mm and six blades. Under the same cutting value, the plane above the stainless steel stamping elbow bag is dry milled for 16.7 points. Compared with the competitor's disc tool, the service life of this stainless steel stamping elbow is significantly improved.
Do you know what are the polishing methods of Stainless Steel Weld Elbow pipe fittings? Below, I will tell you in detail:
1. Mechanical polishing: Mechanical polishing is divided into coarse polishing and fine polishing. During the coarse polishing process, it is necessary to sprinkle a coarser chromium oxide, aluminum oxide or magnesium oxide polishing liquid appropriately, and keep the wool on the polishing disc wet. During the rough polishing process, hold the sample tightly, reciprocate along the radial direction of the polishing disc, and adjust the applied pressure evenly, and pay attention that the pressure should not be too large. At the beginning of polishing, sprinkle some polishing liquid from time to time. Then gradually reduce the pressure and reduce the concentration of the polishing liquid until the fine grinding marks disappear, the surface is flat and bright, and there are no black spots. The rough polished sample is washed with water and then finely polished. The fine polishing is used to remove the grinding marks left by the rough polishing and make the polished surface bright and flat. The polishing machine used for fine polishing is basically the same as the equipment used for rough polishing.
2. Electrolytic polishing: The metal ions detached from the workpiece and the phosphoric acid in the polishing liquid form a layer of phosphate film adsorbed on the surface of the workpiece. This mucous film is thinner at the convex part and thicker at the concave part. Because the current density at the convex part is high, it dissolves quickly. As the mucous film flows, the concave and convex parts change continuously, and the rough surface is gradually leveled.
3. Chemical polishing: Chemical polishing is to make the microscopic convex part of the material on the surface of the chemical medium dissolve first than the concave part, and then smooth the surface. The main advantage of this method is that it does not require complicated equipment, can polish workpieces with complicated shapes, can polish many workpieces at the same time, and the speed is not bad. The core issue of chemical polishing is the preparation of polishing liquid. The bolts of the packing gland of the stainless steel elbow valve should be tightened evenly, and should not be pressed into a crooked state to avoid damage to prevent the valve stem from moving or causing leakage. When the ball valve, stop valve, and gate valve of the stainless steel elbow are used, they are only fully opened or fully closed, and are not allowed to be used for regulating flow to prevent the sealing surface from being eroded and accelerated wear. There are reverse sealing devices in the gate valve and the upper threaded stop valve. The handwheel is rotated and tightened to prevent the medium from leaking from the packing.
When the stainless steel elbow is prevented from corrosion, if the pipeline is thickly rusted, it should be knocked with a hammer first to make the rust layer fall off. When the rust layer is not thick, use a wire brush, wire cloth or coarse sandpaper to scrub the surface until the original color of the pipeline is revealed, and then scrub it with a cotton yarn head. This method is only suitable for scattered and scattered rust conditions and is not suitable for large-scale use. Sandblasting is a relatively effective rust removal method for chemical pipeline corrosion prevention. This method can not only remove the rust layer, old paint layer and other dirt on the surface of the steel pipe, but also form uniform small pits on the surface of the steel pipe. This can increase the bonding strength between the anti-corrosion coating and the metal pipe, improve the effect and service life of the coating, and pave the way for the next step. Stainless steel elbows buried underground generally use chemical pickling, which can remove rust and old coatings. However, it should be noted that although chemical pickling can clean the surface of stainless steel elbows, its anchoring method is shallow and easy to cause environmental pollution. Therefore, chemical cleaning is generally not recommended. Therefore, stainless steel elbows came into being, which are not only not easy to rust, but also strong and beautiful.
