PURPOSE: To produce a lead-containing steel having the specific lead content and excellent machinability by adding the specific grain diameter of fine lead- containing material into a molten steel in the strong stirring with the specific stirring force to make the lead-containing steel and executing at least casting to it.
CONSTITUTION: While stirring the molten steel in a ladle, granular lead- containing materials are added in this molten steel. At this time, the above- mentioned lead-containing materials are added in the condition of ≤50μm the mean grain size. Simultaneously, the molten steel is stirred with the stirring force of ≥60watt/ton of molten steel. Further, addition of the above-mentioned lead-containing materials is desirable to execute at ≤1.0kg/ton of molten steel/ min adding speed. By this method, residue in melting of the lead-containing materials is no produced and the lead can be finely and uniformly distributed. The obtained lead-containing molten steel is at least cast. By this method, the lead-containing steel having ≥0.3% lead content and excellent machinability can be obtd.
YAMAMOTO KIYOSHI
JPS6439345A | 1989-02-09 | |||
JPS60103113A | 1985-06-07 | |||
JPS6444762A | 1989-02-17 |
Next Patent: REFRACTORY FOR LINING OF LADLE FOR PRODUCING HIGH CLEANNESS MOLTEN STEEL