G2A Gray

Dura-Bar G2A contains type D graphite in a predominantly pearlitic matrix. The fine graphite structure allows excellent surface finish and is normally used in permanent mold applications requiring optimal strengths and wear resistance.

CENTER AREA 100x, etched in 5% Nitol EDGE AREA 100x, etched in 5% Nitol

The microstructure will contain Type VII, D, size 6-8 graphite as defined in ASTM A247. The matrix is predominantly pearlite. The rim will be similar to the center. Chill carbides will be less than 5% in any field at 100x and will be well dispersed.

G2 Dura-Bar can be oil quench hardened from 1600° F (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 flakes and not as a loss of matrix hardness. Typical Jominy end quench test data will be comparable to the gray iron curve shown in the Heat Treating Section.