Chemical Passivation of AISI 400 Series Stainless Steel
Original Publication Date: 1985-Oct-01
Included in the Prior Art Database: 2005-Feb-19
A large number of components inside the disk enclosure of a DASD (direct-access storage device) are fabricated from AISI 400 Series stainless steels. Traditionally, passivation of AISI 400 Series stainless steels has been difficult and erratic. Unpassivated surfaces will degrade and generate particles inside the DE (disk enclosure), which may lead to "head crashes" causing a catastrophic failure of the DASD device. However, when the surfaces are passive, they will meet the functional requirements of the disk enclosure. Any chemical passivation treatment has three basic steps: 1. Cleaning and activation of the surfaces. 2. Passivation in a nitric acid bath. 3. Post-passivation treatment. Both cast and wrought surfaces of AISI 400 Series stainless steels can be passivated if they meet the following key requirements: 1.