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...

Nov 30, 2011

High temperatures, low pH, and aggressive chemicals call for a material that exhibits the high corrosion resistance that traditional stainless steel alloys fail to attain. There are many alloys available to address the corrosion issues; but what makes super-austenitic stainless steel alloy AL-6XN® and nickel alloy C-22 the favorite materials for highly corrosive environments? Are the properties more attractive, or is the availability of the material in the required forms more desirable? Is one better than the other? Both AL-6XN and C-22 have a face-centered cubic lattice structure and contain...

Oct 18, 2011

“Purging” is the process of removing air that contains oxygen. Welding is a high-temperature process, so it is very important to keep oxygen and any other gases away from hot metal. We do this to avoid any kind of...

Jun 21, 2011

Material selection can be a difficult decision when you don’t understand the differences between two materials with almost the same cost. Have you ever asked for Hastelloy C-276 material and been recommended Hastelloy C-22 instead? Have you wondered what the difference is between them, and why one should be preferred over the other? Here are few reasons why C-22 is a better choice than C-276:

Sep 22, 2010

1. When the product is corrosive to the piping system. Products containing chlorides and other salts can attack the tubing and fittings used to transport the products throughout a plant. Systems fabricated from 304 or 316 stainless steel can become leaky after prolonged contact with salty food and beverages, e.g. sports drinks and soy sauces. If the product is...

Jul 20, 2010

If you’ve ever heard what sounds like gravel running through your pump, you’ve probably experienced the problems that come from cavitation. Cavitation, the formation and implosion of bubbles inside the pump head, causes more than just an obnoxious noise.  Those tiny bubbles can result in thousands of dollars in repairs due to pitting on the impeller and...