-
- lamellar corrosion.
- See exfoliation corrosion.
-
- lamellar tearing.
- Occurs in the base metal adjacent to weldments due to
high through-thickness strains introduced by weld metal
shrinkage in highly restrained joints. Tearing occurs by
decohesion and linking along the working direction of the
base metal; cracks usually run roughly parallel to the
fusion line and are steplike in appearance. Lamellar
tearing can be minimized by designing joints to minimize
weld shrinkage stresses and joint restraint. See also cold
cracking, hot cracking, and stress-relief
cracking.
-
- Langelier saturation index.
- An index calculated from total dissolved solids, calcium
concentration, total alkalinity, pH and solution
temperature that shows the tendency of a water solution
to precipitate or dissolve calcium carbonate.
-
- ledeburite.
- The eutectic of the iron-carbon system, the constituents
of which are austenite and cementite. The
austenite decomposes into ferrite and cementite on
cooling below the temperature at which transformation of
austenite to ferrite or ferrite plus cementite is
completed.
-
- ligand.
- The molecule, ion, or group bound to the central atom in
a chelate or a coordination compound.
-
- limiting current density.
- The maximum current density that can be used to obtain a
desired electrode reaction without undue interference
such as from polarization.
-
- linear elastic fracture mechanics.
- A method of fracture analysis that can determine the
stress (or load) required to induce fracture instability
in a structure containing a cracklike flaw of known size
and shape. See also fracture mechanics and stress-intensity
factor.
-
- lipophilic.
- Having an amenity for oil. See also hydrophilic and
hydrophobic.
-
- liquid metal embrittlement.
- Catastrophic brittle failure of a normally ductile metal
when in contact with a liquid metal and subsequently
stressed in tension.
-
- local action.
- Corrosion due to the action of "local cells,"
that is, galvanic cells resulting from inhomogeneities
between adjacent areas on a metal surface exposed to an electrolyte.
-
- local cell.
- A galvanic cell resulting from inhomogeneities
between areas on a metal surface in an electrolyte. The
inhomogeneities may be of physical or chemical nature in
either the metal or its environment.
-
- localized corrosion.
- Corrosion at discrete sites, stress-corrosion
cracking.
-
- long-line current.
- Current that flows through the earth from an anodic to a
cathodic area of a continuous metallic structure. Usually
used only where the areas are separated by considerable
distance and where the current results from
concentration-cell action.
-
- luggin probe (Luggin Haber capillary).
- A small tube or capillary filled with electrolyte,
terminating close to the metal surface under study, and
used to provide an ionically conducting path without
diffusion between an electrode under study and a reference
electrode.
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