All of Hero’s hardfacing alloys can be finished by machining or grinding. Grinding is recommended for alloys with hardness higher than RC 55.
Hero Alloys 6, 12, 21 and 31 can be finished by machining. If the hardfaced surface is not smooth enough, manually grinding the surface before machining is recommended. Carbide tooling is required.
Grinding is recommended for alloys with hardness higher than RC 55. Alundum type wheels are recommended. Grinding speeds of 3000 to 4200 ft/minute are used depending on the alloy and parts. The use of coolants will minimize surface cracks.
When coolants are used, it is necessary to pour sufficiently on both the work surface and the grinding wheel to avoid cracks in the weld deposit. If cracks from grinding occur, the following techniques are recommended; frequent dressing of the grinding wheel, reducing the grinding depth and feed, increased work speed, changing to a softer grade wheel and decrease the wheel speed.