Super-Austenitic Stainless Steel Alloys: A Comparison

Super-Austenitic Stainless Steel Alloys: A Comparison

Oct 7, 2015

In the high-purity and sanitary industries, products such as shampoos, conditioners, deodorants, sports drinks, ketchup, salsa, active pharmaceutical ingredients, etc. require extremely corrosion-resistant material to withstand the high concentration of chemicals (chlorides), high temperatures, and low pH. When faced with similar corrosion-resistant alloys, your purchasing decision should be influenced by which material is readily available.

Are microbes eating your sanitary process system?

Are tiny microbes feasting on your precious product line? Corrosion resistant alloys (CRA) are used for almost every equipment, machinery, or apparatus used in the food, dairy, and beverage manufacturing. Despite that, the maintenance costs due to corrosion in these kinds of equipment are surprisingly very high. The current research in Corrosion Science and Engineering, tells us that microbes or bacteria have been causing...

9 Unacceptable Welds for High Purity Applications

9 Unacceptable Welds for High Purity Applications

Aug 12, 2015

Have you ever wondered why welds fail? When welding in a high purity environment, several factors can render a weld unacceptable: heat tint, a lack of...

Poll: Does Stainless Steel Contain Iron?

Poll: Does Stainless Steel Contain Iron?

Dec 18, 2012

We are always curious about thoughts regarding stainless steel. Please take 30 seconds to respond to this poll.

Passivation vs. Electropolishing – Part 2

Passivation vs. Electropolishing – Part 2

Jan 7, 2012

Is electropolishing actually necessary given that a 1.0 or greater Cr/Fe ratio can be achieved by passivation alone? The real question is, “Are we trying to only passivate the surface or are we trying to produce a corrosion resistant cleanable surface?” Chemical passivation will attain a chrome to iron ratio above 1.0 (Cr/Fe), without producing any measureable change in the finish characteristics of the surface. Electropolishing is designed to remove surface damage from mechanical polishing and produce a more cleanable, featureless, smooth surface finish. The need to electropolish a surface is dependent upon...

Passivation vs. Electropolishing

Passivation vs. Electropolishing

Dec 11, 2011

Is electropolishing actually necessary given that a 1.0 or greater Cr/Fe ratio can be achieved by passivation alone? The short answer? If a 1.0 Cr/Fe ratio is all you are trying to achieve, no it is not. Now for the long answer. First, the 1.0 or greater Cr/Fe ratio indicated in the ASME BPE standard is a minimal requirement. The best passive and corrosion-resistant surfaces will have a Cr/Fe ratio in excess of 1.5/1, again achievable by passivation alone. The pharmaceutical industry, in most cases, requires a 15-25Ra value typically achieved through a mechanical polishing procedure. It is this procedure that, in my opinion, causes many of the problems experienced today with the formation of the “gray residue” and Class 1 rouge that has plagued end users for years.