Elimination of Acid Cleaning
Can acid cleaning be removed to reduce pollution?
Q. At present, we are doing acid cleaning, sand blasting and a buffing operation for an induction hardened shaft before hard chrome plating. To reduce pollution, we conducted a trial by eliminating the acid cleaning and found that the plating quality was good. Is it OK or not? Please provide your feedback.—S.G.
A. The acid cleaning and sand blasting would likely accomplish similar objectives, in that they would both have the ability to remove oxidation from the induction hardening process. I assume you are performing the same quality evaluations with the new process and found it to be acceptable. Also, I would suggest you do some additional trials to test the limits of this process when the induction hardening has produced the worst oxidation and scale on the part. That will be the best test to evaluate if you can eliminate this step permanently.
Better adhesion, enhanced corrosion and blister resistance, and reduced coating-part interactions make pretreatment a must.
A more realistic way to perform salt spray tests.
Powder coating is one of the most durable finishes that can be applied to industrial manufactured products, and offers excellent corrosion protection and is very safe because of its lack of volatile organic compounds.