白口铁的稀土变质处理对热处理时碳化物团聚化的影响

EFFECT OF RE MODIFICATION ON AGGLOMERATION OF EUTECTIC CARBIDES IN HEAT TREATMENT OF WHITE CAST IRON

从改变共晶碳化物形貌的角度研究了稀土变质处理与热处理两者之间的内在联系及相互作用。结果表明,变质后再进行热处理可以显著地加速白口铁共晶碳化物的溶解,断网与团聚化,并明显地提高韧性,综合运用变质处理和热处理是改变白口铁共晶碳化物网状分布,提高韧性的有效途径。

The interrelationships between rare earth modification and heat treatment of white castiron have been investigated with the view of obtaining granular carbides and high toughness.Experimental results indicate that by combinig rare earth modification with heat treatment thebreaking up of eutectic carbide network at as-cast state is effected,and the dissolution and ag-glomeration of eutectic carbides are notably accelerated during high temperature holding of themodified white cast iron.As a result,the toughness of the white cast iron is greatly improved.Combination of RE modification and heat treatment is an effective way to alter the morphologyof eutectic carbides and increase the toughness of white cast iron.