Study of physical and mechanical properties of sleeves surfaces after broaching
Experimental studies of combined cutting broaching on steels 10 and 35 were conducted. Among the phase components of iron-carbon alloys, prone to plastic deformation, and thus to the texturization at a temperature, characteristic of broaching, there are solid solutions of carbon in iron - ferrite and austenite. Cementite as a chemical com- pound of iron and carbon is hard and brittle; therefore it is destroyed under large deformations. Perlite as eutectoid mixture of ferrite and cementite is deformed due to the ferrite plates. Based on the fore- going, steels from the selected series, which have ferritic-pearlitic structure in the unhardened state are prone to the texturization at cutting broaching.The aim of the work is experimental verification of validity of the recently discovered phenomenon of phase formation through a stage of liquid state in metals being electrodeposited. The idea of the work is based on the known fact, that during crystallization of liquid phase of a transitional metal (e.g. chromium) alloyed in significant concentration with non-metal of minor atomic radius (e.g. hydro- gen) intermediate phases with simple crystal lattices (e.g. hydrides) appear. Therefore, if in electrodeposited chromium alloyed with hydrogen the chromium hydride will be detected, this result will indicate validity of the phenomenon of phase formation through a stage of liquid state in metals being electrodeposited. To find the variants of chromium alloying with hydrogen during its electrodeposition the method for estimation of the degree of hydrogen saturation of metals being electrodeposited is developed. Electrodeposition of chromium was accomplished in such conditions where the volume of hydrogen being formed on the cathode was62700 times higher than the volume of chromium being formed, which indicated alloying of chromium during its electrodeposi- tion with hydrogen in significant concentration. On the basis of the accomplished experiments the formation of chromium hydride during electrodeposition of chromium alloyed with hydrogen was found. The conclusion, that existence of intermediate phases in electrodeposited metals is a result of crystallization of liquid metallic phase being formed during electrochemical deposition of metals, was made. The obtained result proves the validity of the phenomenon of phase formation through a stage of liquid state in metals being electrodeposited.