After investment casting, stainless steel castings can achieve good dimensional tolerances, excellent surface finish and machining can be saved in most cases. With a long history on stainless steel investment casting, CFS Foundry is experienced in different surface finishes for stainless steel castings, this capability enables our company to fulfill different surface finish requirements from our customers. Common surface finishes of stainless steel investment castings are listed as follows:
Shot blasting is the surface finish method by impacting steel balls on the surface of stainless steel castings under high speed. This type of surface finish can remove the oxide layer after stainless steel casting effectively. Among all the surface finishes, shot blasting is the most common and cheapest surface finish method.
Sand Blasting is the surface finished way to blast the surface of stainless steel castings by fine sand. The surface of sand blasted stainless steel castings is more fine and smooth than that of shot blasted ones. If there is a higher requirement on the surface of stainless steel castings, sand blasting is recommended, but cost is relatively higher.
Pickling and Passivation
Both pickling and passivation are chemical treatments applied to the surface of stainless steel castings to remove contaminants and assist the formation of a continuous chromium-oxide, passive film. All the stainless steel castings will be cleaned by pickling process at least.
Electropolishing significantly improves the corrosion resistance of stainless steel castings, leaving it with a lasting bright finish. Electropolishing can be performed on all varieties of stainless steel castings. After electropolishing, stainless steel castings exhibit silver color and look much more bright than before.
Vibratory Polishing is a process of mass finishing and is most often used to burnish, clean, deburr, deflash, degrease, descale, radius, refine, dry, and offer pre-plate or pre-paint finishes of stainless steel castings, amongst other various process applications. Vibratory Finishing is one of the most common style of mass finishing. It’s preferable to other methods of deburring in that it allows the load to move as one unit – this prevents stainless steel castings from being bent or distorted.
Mirror Polishing is a mechanical polishing process that workers polishing stainless steel castings with various polishing machined by hand. There are several procedures involved during the mirror polishing process, including grinding wheel polishing, hemp wheel polishing and cloth wheel polishing. After mirror polishing, the surface of stainless steel castings can achieve very smooth and bright surface finish, looks like a mirror. Although the cost of mirror polishing is higher than that of other surface finishing methods, it is still is a common surface treatment way to improve the surface finish of stainless steel castings, especially for luxury goods, which are used for high-end market applications.
PVD coating is the ideal surface finish way to color stainless steel castings. Vacuum titannium coating require a relatively smooth surface, after stainless steel castings, the parts are better to mirror polished or at least electropolished. There are various colors selected to color stainless steel castings, such as gold, rose gold, etc.
CFS Stainless Steel Foundry can supply all above surface finishing processes. No matter what type of surface finish required, we can all meet your demands. If you are not familar with the differences between these surface finishes, we can suggest an ideal one, or can even supply samples with different surface finishing ways for your comparison.