Excavator bucket teeth and cutting edges, loader bucket lips, dozer blades, ripper teeth, mill hammers and grates, rock crusher wear plates, plow shares, harrow disks, and wear surfaces on conveyor systems all benefit.
Anything that runs against rock, dirt, ore, or abrasive material is a hardfacing candidate. The cost of laying down a hardfacing pass is a fraction of replacing the part, and the part comes back tougher than it was originally.