Ask the Metals Experts

FROM THE DESK OF THE METALS EXPERTS

Welcome to the MetalTek Blog.

As your Metals Partner, it is our goal to educate you on various casting processes. Feel free to browse around to learn more but if you have questions or need to submit an RFQ, please contact us. MetalTek International. Because You Demand More Than Metal.

Material Applications: Wear Resistance

Posted by Dave Olsen on 9/6/16 3:46 PM

Wear is probably the most common cause of material replacement in industry. Bushings and bearings are common examples of components which must provide metal-to-metal wear resistance.  Wear is a universal constant in moving equipment in all applications.

In some applications like food processing the use of certain materials that provide superior wear resistance (copper-based alloys, for example) is restricted or prohibited. In these applications, specific alloys have been developed to eliminate certain types of wear, like galling, without reacting with the environment. In the case of food processing applications, for example, a series of “dairy metals” has been developed to prevent these types of wear.  When corrosion-resistance is the primary concern, high-performance cobalt-based alloys are often specified.

Read More

Topics: Alloy Selection, Wear Resistance, Physical Properties, Mechanical Properties

Material Applications: Corrosion Resistant Alloy Comparison Part: 1

Posted by Dave Olsen on 9/6/16 3:27 PM

Every material selection decision includes tradeoffs. Performance can come at a price.  But there is little sense in paying for capabilities that are not needed.  The following suggests a framework for selecting one of a family of corrosion-resistant materials from another.

Read More

Topics: Alloy Selection, Corrosion Resistance, Physical Properties, Mechanical Properties

What Is Pitting Resistance Equivalency Number (PREn)?

Posted by Dave Olsen on 9/6/16 3:14 PM

The Pitting Resistance Equivalency Number (PREn) is an objective way to do an initial comparison of the relative resistance to corrosion of various metals. It is based on a calculation that considers the weight percentage of alloying elements.

PREn = % Cr + (3.3 x % Mo) + (30 x % N)

A simple examination of the components of the PREn calculation indicates those alloys that contribute to corrosion resistance. Chromium, Molybdenum and Nitrogen are all included because their presence in the alloy grade, in combination, contributes to corrosion resistance.  Sometimes Tungsten is also included in the calculation because of its contribution to pitting resistance.

Read More

Topics: Alloy Selection, Corrosion Resistance, Physical Properties, Types Of Corrossion, Mechanical Properties, PREn

Material Applications: Corrosion Types

Posted by Dave Olsen on 9/6/16 3:06 PM

No engineering alloy is immune to corrosion; each has its own corrosion rate depending on the environment in which it is placed. This paper identifies some common types of corrosion, what the results of its presence may be, and how it may be minimized.

Some of the more common types of corrosion are discussed below:

Read More

Topics: Alloy Selection, Corrosion Resistance, Physical Properties, Types Of Corrossion, Mechanical Properties

Material Applications: Corrosion Resistance

Posted by Dave Olsen on 9/6/16 2:46 PM

Corrosion is the loss of metal due to a reaction with the environment, and is measured as the percentage of weight loss or as the penetration rate of the corrosion, perhaps measured in inches per year.

Corrosion can develop in the presence of liquids or gases. It may occur at any temperature, although generally the rate of corrosion increases with increasing temperature. Corrosion associated with liquids is often caused by impurities or by trace elements within the liquid. Examples of that would be the presence of chlorine, which encourages formation of hydrochloric acid, or of sulfur, which forms sulfuric acid.

It is important to remember that any alloy, stainless steel or otherwise, can corrode under certain circumstances. The presence of corrosion does not necessarily indicate faulty product; it may instead indicate an improper application of that product – perhaps using a material that is not the best fit for a given environment, for example.

Read More

Topics: Alloy Selection, Corrosion Resistance, Physical Properties, Mechanical Properties

MetalTek International
Download Our Alloy Guide 
Download Our Where Used Guide 

Follow Us