METHOD OF STEEL ITEMS SURFACES HARDENING Russian patent published in 2005 - IPC

FIELD: engineering industry; methods of chemical-thermal surface treatment of steel items.

SUBSTANCE: the invention is pertaining to chemical-thermal surface treatment of steel, in particular, to the methods of hardening of steel with the help of an electric arc of a reversed polarity and may be used in engineering industry for increase of wear resistance of machine components and a different cutting tools. A problem being solved by the invention is an increase of hardness of steel items treated surfaces. The task in view is achieved provided, that in the known method including heating by an electric arc of a reversed polarity stricken between a graphite electrode and a surface of an steel item at a relative motion of the arc and the item the electric arc is constricted by a noble gas jet up to the value of a power density of 10³ W/cm². The electric arc of a reverse polarity stricken between the graphite electrode and the surface of the steel item burning in the medium of a noble gas melts down the surface layer of the item and so carbonization of the surface of the layer takes place as well as an ultrahigh-speed quenching at the expense of big values of a power density of the electric arc and a quick chilling of the layer surface due to the heat withdrawal deep into steel items. It results in an increase of microhardness of the surface layer in depth to 1.2 mm, that in turn results in an increase of wear resistance of the steel item.

EFFECT: the invention ensures increased microhardness of the surface layer in depth to 1.2 mm and increased wear resistance of the steel items.

1 dwg, 1 ex