PURPOSE: To make a remelted chilled layer on the surface of cat iron free from blow holes by adding a proper amount of a specified element having a deoxidizing effect to cast iron when the surface of the cast iron is hardened with a high density energy source such as inert gas arc.
CONSTITUTION: The surface of cast iron is melted by heating with a high density energy source such as inert gas arc, electron beams or laser, and it is self- cooled to form a cementite-base chilled layer. Thus, the surface of the cast iron is hardened. At this time, to the cast iron is added 0.003W0.020wt% Ce or 0.015W0.080wt% in total of Ca, Al, Zr and Zn among elements each having a deoxidizing effect. Ce or Ca, Al, Zr and Zn bond preferentially to oxygen and inhibit gasification during the remelting of the surface of the cast iron by heating, so the resulting chilled layer can be made free from blow holes.
FUKUMIZU TOSHIHARU
MORITA AKIYOSHI
| JPS5149573A | 1976-04-28 |