| 摘要 |
<p>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 <=50mum 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.</p> |
