Many materials used in critical applica· tions must be tested at low temperature to simulate their operating environment or, as with ferritic steels, it is important to know their behavior at the ductile· to-brittle transition. In the latter case the temperature control of the test must be very accurate because of the abrupt variation that steel properties suffer in a narrow temperature range.Comisión de Investigaciones Científicas de la provincia de Buenos AiresFacultad de Ingenierí
