Hardening Wear Resistant Coatings by Heat Treat? Yes!

Hardening wear resistant coatings created by heat treat? Of course. But, with so many processes available, where do you start? How do you choose?

Start with an understanding of your metal chemistry. For example, dimensionally stable steels, those with higher carbon and higher chromium content, are known for their great resistance to wear. Because of chromium, other favorable carbide forming elements too, like tungsten, manganese or molybdenum, can produce high hardness.

But, besides alloy composition, consider material stress relief, tempering or austenitizing temperatures. If you want the best distribution of carbide, hardness quality of the metal matrix, that is.

How do we define hardness, anyway? Generally speaking, hardness is a measurement of a surface's ability to resist indentation, deformation, when another object is applied with pressure against it. Values reflect specific loads, over given areas, by counter-face indentation, of known material properties. Want more information for Hvof Thermal Spray Coating and Tungsten Carbide Coating On Steel? 

Heat treatment options are wide and vary. And they're very specific. So, do know the differences among these thin films. Otherwise, negative outcomes can include, depending on metal and heat treat process, inter-granular (oxidation) cracking, the breakdown in the grain boundary, precipitant formation, retained austenite, and other issues.

"Ion nitriding" steel, for example, involves diffusion of nitrogen into the metal. Based on reactions between electrically ionized nitrogen with alloying elements, harder surfaces, though superficial, are formed. Another choice in heat treating is "carburizing." There, higher temperatures are needed to diffuse carbon into the metal surface, to a specific depth, for the production of martensite. Here is a video for better understanding of Wear Resistant Coatings. 

Before you choose your heat treat, understand these processes, their effects on metallurgy, and what surface properties best fit your needs. Only then, will your hardening wear resistant coatings serve you best!