Light micrograph of a section through a case- hardened steel tool, photographed using differential interference contrast (DIC). The brown area shows t

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Light micrograph of a section through a case- hardened steel tool, photographed using differential interference contrast (DIC). The brown area shows the original low-carbon (soft) steel, the orange area is case-hardened. Case hardening is performed when soft steel has been used to manufacture a tool, allowing easy finising of the piece. In order to harden the surface, the tool is either heated in a hydrocarbon atmosphere, or dipped into liquid sodium cyanide. Carbon atoms diffuse into the surface, providing a layer of hardened (high- carbon) metal.

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Size: 4723px × 3526px
Photo credit: © ASTRID & HANNS-FRIEDER MICHLER/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: alloy, case, chemical, chemistry, compound, compounds, harden, hardened, hardening, materials, science, section, steel, thin