Production Machining - Your access to the precision machining industrial buyer.
Issue link: https://pm.epubxp.com/i/196884
TECH BRIEFS add a pre-cleaning operation, such as vapor degreasing or alkaline cleaning. In the past, passivation was typically preceded by a pre-cleaning process known as "pickling." Te pickling solution, made from a hydrofuoric acid mixture, was used for dissolving embedded steel fecks and removing the heat tint and oxide scale. Due to EPA regulations, most companies have eliminated pickling. Without this aggressive pre-cleaning operation, in many cases, passivation does little to improve the corrosion resistance of stainless steels. Te electropolishing process is often used as a more aggressive alternative to passivation (per ASTM B912 and ASTM A967) and does not require a separate treatment. Since the process removes the outer skin of metal, embedded contaminants that can cause sub-surface corrosion are eliminated. Te electropolished part is left in a homogenous and passive condition. An Efective Option :: The electropolishing process uses a combination of rectifed current and a blended chemical electrolyte bath to remove faws from the surface of a metal part. include deburring, size control, microfnish improvement and others that can ofer great promise to design and production engineers looking to lower costs and still provide a better product. Although the process is roughly 65 years old, substantial refnements have taken place. Many electrolytes have been developed to allow for electropolishing of a range of metals. Tese newer electrolytes, together with advanced parts handling techniques, have combined to improve production yields on a range of metal products. Passivation Parallel Passivation is a chemical process that is used to help restore contaminated stainless steel to original corrosion specifcations. Parts are placed in baskets and submersed into a diluted nitric acid or citric acid solution for a specifc length of time and temperature. Tis process is designed to remove free iron or other foreign matter from the surface of the metal. Passivation, however, is not efective for removing heat tint or oxide scale as a result of heat treating or welding. Other than giving the part a clean fnish, the process does not brighten or change the part appearance. To attain a contaminant-free part, it may be necessary to Since electropolishing removes surface metal, all surface impurities are removed as well. Heavily contaminated surfaces such as machined parts, welded or brazed assemblies or other components that typically respond poorly to passivation alone are good candidates for electropolishing. Several popular grades of stainless steel cannot be passivated because of low levels of chromium and nickel. When these stainless steels are passivated by standard methods, the resultant fash attack actually weakens the base material and does irreparable damage to the part. Just as electropolishing is used to enhance corrosion resistance on stainless steel, it ofers corrosion resistance on other alloys as well. Many companies use the process to delay the corrosion properties of copper, brass, aluminum and carbon steels. On these and other alloys, the removal of surface skin and impurities enhances the corrosion resistant properties of the component. For components needing light corrosion resistance that cannot aford an expensive plating operation, electropolishing may be a solution. Electropolishing Infographic Check out this breakdown of electropolishing details, including the metal treatment benefts it provides. LINK :: short.productionmachining.com/2bdfpeun For more information: Able Electropolishing Co. Inc. :: 773-277-1600 ableelectropolishing.com productionmachining.com :: 27