MIL-DTL-46100E (MR)
6.10.2 Laps. A surface imperfection with the appearance of a seam, caused by hot metal,
fins or sharp corners being folded over and thus being forged or rolled into the surface but
without being welded.
6.10.3 Checks. Checks are numerous very fine cracks at the surface of a metal part. Checks
may appear during processing or during service and are most often associated with thermal
cycling or thermal treatment. Also called check marks, checking, heat checks.
6.10.4 Seams. Seams are an unwelded fold or lap that appears as a crack, usually resulting
from a discontinuity on a metal surface.
6.10.5 Blisters. A raised area, often dome shaped, resulting from delamination under
pressure of expanding gas trapped in metal in a near sub-surface zone. Very small blisters
may be called pinhead blisters or pepper blisters.
6.10.6 Snakes. Any crooked surface imperfection in a metal plate, resembling a snake.
6.10.7 Cold shuts. A lap on the surface of a forging or billet that was closed without fusion
during deformation.
6.10.8 Burning. Permanently damaged metal due to overheating enough to cause incipient
melting or intergranular oxidation. Note: This condition is usually obscured by normal
cleaning methods and would require deep pickling and/or metallography to note the
continuous oxidation (chicken wire effect) of the enlarged grain boundaries. This defect is
usually not limited to the surface and may be sub-surface or at interior locations when
associated with heavy mechanical working. Metal with this condition will be scrapped.
6.10.9 Laminations. A type of discontinuity with separation or weakness generally aligned
parallel to direction of the worked surface of the metal and may be the result of pipe
blisters, seams, inclusions, or segregation elongated and made directional by working.
6.10.10 Linear indication. For nondestructive examination purposes, a linear indication is
evidence of a discontinuity that requires interpretation to determine its significance.
6.10.11 Autotempering. When the martensite start temperature (MS) lies well above room
temperature, carbide precipitation (tempering) occurs upon quenching, after the
transformation to martensite. Also called quench tempering.
6.11 Tempering. Any tempering should be performed as soon as possible after quenching.
It is recommended that the delay after quenching be no greater than 24 hours.
6.12 Plates in the as-rolled condition. When the fabricator performs the final quench and
temper of plates, it will be his responsibility that the mechanical and ballistic requirements
of the plates, meet this specification.
6.13 Bend test inspection tests. If additional tests are required in the contract or purchase
order, the following could be specified: "After bending, samples should be free of cracks as
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