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The Development of a Test Method for Evaluating the Chipping Resistance of Outer Panels
Technical Paper
825044
Sector:
Language:
English
Abstract
An important concern in recent years has been how to prevent
automobile body corrosion caused by the deicing salts used in
snow-belt areas. One particularly serious problem is the paint
damage caused by stone chipping, which in turn leads to chipping
corrosion.
There are several techniques, such as the gravelometer method,
which can be used to evaluate chipping resistance. However, these
methods do not afford sufficient accuracy and repeatability to be
of practical use in evaluating actual chipping conditions on
vehicles in operation. This report presents a new evaluation test
method which offers good repeatability and sufficient accuracy to
be applicable for evaluating field chipping conditions.
In this method a diamond crystal is shot by compressed air at a
painted panel at a velocity which corresponds to the actual driving
speed (50 - ]50 km/h) in the field. The chipping resistance is
evaluated using the damage depth and the panel beating speed. Tests
conducted on various painted panels obtained from domestic and
foreign makers confirmed the repeatability of this method for
evaluating stone chipping. The results of these tests show that the
proposed method affords superior accuracy and repeatability as well
as excellent applicability for quantitative evaluation.