Part for casting steel and conversion process of its layer

摘要

The invention relates to a part for the casting of steel, said part comprising a body (2) made of carbon-containing refractory material. The part has a layer (10) which coats partially or completely the body (2) and is capable to form a gas impervious layer (10a) which is oxidized and densified when brought to a temperature higher than 1000 degC. The layer (10) is comprised of a refractory material having sintering precursors being selected from the group comprising calcined alumina, reactive calcined alumina, silica fumes, and clay. Process for producing such part for casting steel is characterized in that a densified gas impervious layer (4a, 10a) is formed on a surface of a sprue (9) during heat treatment phase.