Datasets / Citric Acid Alternative to Nitric Acid Passivation Project


Citric Acid Alternative to Nitric Acid Passivation Project

Published By National Aeronautics and Space Administration

Issued over 9 years ago

US
beta

Summary

Type of release
a one-off release of a single dataset

Data Licence
Not Applicable

Content Licence
Creative Commons CCZero

Verification
automatically awarded

Description

<p>Corrosion is an extensive problem that impacts National Aeronautics and Space Administration (NASA) and Department of Defense (DoD).  The deleterious effects of corrosion result in steep costs, asset down-time affecting mission readiness, and safety risks to personnel.  Consequently, it is vital to reduce corrosion costs and risks in a sustainable manner.</p><p>NASA and DoD have numerous structures and equipment that are fabricated from stainless steel.  The standard practice for protection of stainless steel is a process called passivation which removes free iron contamination from the surface and forms a metal oxide layer to prevent corrosion.  Typical passivation procedures call for the use of nitric acid which exhibits excellent corrosion performance; however, there are a number of environmental, worker safety, and operational issues associated with its use.</p><p>The longtime military specification (QQ-P-35C) for the passivation of stainless steel was cancelled in favor of newer specifications which allow for the use of citric acid in place of nitric acid.  Citric acid offers a variety of benefits that include increased safety for personnel, reduced environmental impact, and reduced operational cost.  There have been few studies, however, to determine whether citric acid is an acceptable alternative for NASA and DoD applications; therefore, NASA and DoD agreed to collaborate on an effort to validate citric acid as an acceptable passivating agent for stainless steel. </p>