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How to Visually Detect Flaws and Characteristics in Rolled Aluminum

Quiz Questions

1.Measurement of flatness, especially for thin sheet, is often made in terms of:
“I” units
2. Longitudinal bow is usually caused by :
Bad handling of the roll during the shipping
Unbalanced stresses between the top and bottom surfaces of the rolled aluminum
3.Arbor buckles are caused by plastic bending over a coil and in contact with:
The mandrel
The longitude edge laying underneath the roll
The cross edge laying underneath the roll
4. Bond blisters are caused by:
Expansion of gas from a localized incomplete bond
Rolling against the material grain direction
Dropping the roll during the shipping
5.Burr is :
Rolled surface rubbing against each other
A thin ridge of roughness left by a cutting operation such as slitting, trimming, shearing, blanking or sawing
6.Repeating dent on a roll can be caused by a particle adhering to a rotating roll across which the metal has passed.
7. Edge containing crack, split, and/or tear which is caused by;
defective material
too short of a roll radius
Inability to deform without fracturing
8.An embossed pattern distortion is caused due to:
Misalignment of the male and female embossing rolls
Substandard material
9.Rolled-in metal is an extraneous chip or particle or metal rolled into the surface of the product.
10.Surface discoloration which may vary from dark brown to white is produced:
During thermal treatment by incomplete evaporation and /or oxidation of lubricants on the surface
Oil leak from the rolling machine
Discrepancies in the ingot during solidification