Atlas carries 80-55-06 Ductile Iron will contain nodular graphite in a matrix of ferrite and
pearlite. The pearlite/ferrite structure provides higher wear resistance
and strength when compared to a ferrite grade of ductile iron. This
material is readily machinable with good surface finishes. Tensile and
yield strengths are similar to AISI1040 steel in the as-rolled
condition. This specification is similar to ASTM A536 grade 80-55-06.
HEAT TREAT RESPONSE:
80-55-06 can be oil quench hardened from 1600° (885° C) to a minimum
hardness of Rockwell C 50 on the outside of the bar. The inside diameter
hardness will be less than Rockwell C 50. Lower quench hardness on the
inside diameters are a result of larger graphite nodules and not a loss
of matrix hardness. Typical Jominy end quench test data are shown in the
section on Heat Treating.
microstructure consists of Type I & Type II nodular graphite as
defined in ASTM A247. The matrix is pearlite and ferrite. The "rim" has a
higher nodule count and ferrite content. Chill carbides will be less
than 5% in any field at 100x and will be well dispersed.