PRODUCTION OF AS-CAST SPHEROIDAL GRAPHITE CAST IRON OF PEARLITE CASE

摘要

PURPOSE:To produce titled spheroidal graphite cast iron of superior mechanical properties by casting molten metal contg. C, Si, Mn, Mg, Cu and the balance Fe into molds, and solidifying and cooling this at specific cooling rates to the end of eutectic transformation. CONSTITUTION:The molten metal contg., by weight %, 3.5-4.2% C, 2.3-3.3% Si, =0.5% Mn, 0.02-0.06% Mg, 0.3-2.0% Cu and consisting of the balance substantially Fe is cast into molds. This is solidified and cooled at 7.8-13 deg.C/min cooling rates in the temp. region from the start of solidification till the end of eutectic transformation, whereby the cast iron having the structure wherein spheroidal graphite crystallizes finely and uniformly in the approximately perfect pearlite case in an as-cast-state is produced.