G2 Gray

Dura-Bar G2 is a pearlitic gray iron containing Type A graphite. Gray Iron bars made to this specification have optimal strength, wear and hardness when compared to the other gray iron grades. This material is well suited for applications requiring high resistance to wear and response to heat treatment. This specification is similar to ASTM A48 class 40.

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

The microstructure will contain Type VII, A, size 4-6 graphite as defined in ASTM A247. The matrix is fully pearlitic. The rim will consist of Type D, size 4-6 graphite in a pearlite matrix with small amounts of ferrite. Chill carbides will be less than 5% in any field at 100x and are well dispersed.

Dura-Bar G2 can be hardened by fast methods, such as flame and induction hardening, in addition to conventional quench and temper methods.

Dura-Bar G2 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 loss of matrix hardness. Typical Jominy end quench test data are shown in the section on Heat Treating.