plating, anodizing, & finishing Q&As since 1989
Looking for corrosion performance chart for steel
Trying to find a chart of some sort showing corrosion performance differences between unplated steel, zinc chromated steel and stainless steel. The three examples I gave are specific but the chart can include other coatings as well. I would appreciate it if someone could point me in the right direction.Tom Campbell
- Seattle, Washington, USA
Good luck, but I don't think you'll find what you seek. I have seen charts that rate materials by thousandths of in inch lost per year by immersion in water or sulfuric acid, and some other conditions. Ratings for other than chemical immersion service are tricky. But bare steel will rust immediately and is unsuitable for almost any purpose except chemical immersion; stainless steel should not rust under normal atmospheric conditions; and chromated zinc plated steel should last several years depending on the exact service conditions and the thickness of the zinc and the type of chromate. Not much help, but it's a complex problem.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Although plated finishes are not included, the most comprehensive corrosion chart on base metals from steel to various stainless grades, Hastelloy, Monel, etc. are found in the "Chemical Engineers Handbook" [affil. link to book on Amazon], Perry & Chilton, published by McGraw-Hill. You can also find data in various websites listing salt spray corrosion data on zinc plated steel, alloy plated steel and perhaps a comparison to various stainless steels and mild steel. The manufacturers of the leading proprietary zinc and zinc alloy plating processes should have some data on this.Chuck Reichert
- Seattle, Washington