ASTM International - ASTM G5-12
Standard Reference Test Method for Making Potentiostatic and Potentiodynamic Anodic Polarization Measurements
|Publication Date:||15 November 2012|
|ICS Code (Physicochemical methods of analysis):||71.040.50|
significance And Use:
3.1 The availability of a standard procedure, standard material, and a standard plot should make it easy for an investigator to check his techniques. This should lead to polarization curves in the... View More
3.1 The availability of a standard procedure, standard material, and a standard plot should make it easy for an investigator to check his techniques. This should lead to polarization curves in the literature which can be compared with confidence.
3.2 Samples of a standard ferritic Type 430 stainless steel (UNS S43000) used in obtaining standard reference plot are available for those who wish to check their own test procedure and equipment.3
3.3 Standard potentiostatic and potentiodynamic polarization plots are shown for a lot of material originally purchased in 1992. This test method is not applicable for standard material purchased before 1992. These reference data are based on the results from different laboratories that followed the standard procedure, using that material in 1.0 N H2SO4. The four sigma probability bands for current density values are shown at each potential to indicate the acceptable range of values.
3.4 This test method may not be appropriate for polarization testing of all materials or in all environments.
3.5 This test method is intended for use in evaluating the accuracy of a given electrochemical test apparatus, not for use in evaluating materials performance. Therefore, the use of the plots in Figs. 1 and 2 is not recommended to evaluate alloys other than Type 430, or lots of Type 430 other than those available through ASTM. The use of the data in this test method in this manner is beyond the scope and intended use of this test method. Users of this test method are advised to evaluate test results relative to the scatter bands corresponding to the particular lot of Type 430 stainless steel that was tested.
CURRENT DENSITY (μA/cm2)
FIG. 1 Typical Standard Potentiostatic Anodic Polarization Plot CURRENT DENSITY (μA/cm2)
FIG. 2 Typical Standard Potentiodynamic Anodic Polarization Plot
1.1 This test method covers an experimental procedure for checking experimental technique and instrumentation. If followed, this test method will provide repeatable potentiostatic and potentiodynamic anodic polarization measurements that will reproduce data determined by others at other times and in other laboratories provided all laboratories are testing reference samples from the same lot of Type 430 stainless steel.
1.2 Units-The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.