Corrosion Removal of Case Hardened Steel
How do I clean a planet gear made of low alloy steel?
Q. I have a planet gear made of low alloy steel (per AMS 6265) that is corroded on the surface. How do I clean this? Can I descale the parts? What type of process is involved?
A. The referenced steel (AMS 6265) is primarily nickel-alloyed (~3.25 percent) with lower alloying levels of chromium, molybdenum, manganese, silicon and carbon. This alloy may also be case-hardened to increase surface hardness while retaining the base material ductility. It may be possible to preferentially remove surface carbon, degrading the performance of the part, depending on if it is hardened and the type of chemistry or acids used to remove scale. It would be safest to use a mechanical cleaning or blasting method to remove surface corrosion and scale.
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The German Association of the Automotive Industry’s VDA Volume 19 is the first comprehensive standardization document for characterizing the cleanliness of products within the automotive industry’s quality chain.