CARBON STEEL BORONIZING METHOD Russian patent published in 2007 - IPC C23C8/70 C23C8/02 

FIELD: metallurgy, namely thermal-chemical working, possibly for surface hardening of tools and machine parts.

SUBSTANCE: method comprises steps of preliminarily working and boronizing. Preliminary working is performed by means of electron beam in vacuum (P=2 x 10^-3Pa) for 30 s at specific power ( 4 - 5) x 10⁴ Wt/cm². Boronizing is realized at temperature 940°C for 3 h in container having melting lock and filled with saturating mixture containing 97% of B₄C and 3% of KBF₄.

EFFECT: boronizing process providing surface hardening of tools, lowered brittleness of boride layer with increased thickness, reduced stresses in boride zone.

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