Because of unfavorable parameter during the solution annealing,
too high temperature or too long holding time, strong scale layers can be formed.
This scale layer is partly accompanied by stronger formation of scars. Unless by
wrongly selected annealing parameters, a furnace disturbance yields the same defect
picture. If such handicapped material is then processed to ground bars, rests of
these scaled scars can remain on the surface. This defect appears if the allowance
for the grinding is smaller than the defect depth at the pre-material.
12,00 mm round - solution annealed , ground