Boronizing is a thermochemical surface-hardening process that can be applied to a wide variety of ferrous, nonferrous, and cermet materials. The boronizing pack process is similar to pack carburizing with the parts to be coated being packed with a boron-containing compound such as boron powder or ferroboron. Boronizing is most often applied to tool steels or other substrates that are already hardened by heat treatment. When applied to the appropriate materials, boronizing provides wear and abrasion resistance comparable to sintered carbides.
Boroscopic testing is a visual inspection test for internal heat exchanger and tube failures using fiber optic and rigid boroscopes, including photography or videotape.