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3.1 An indication of the susceptibility to initiation of localized corrosion in this test method is given by the potential at which the anodic current increases rapidly. The more noble this potential, obtained at a fixed scan rate in this test, the less susceptible is the alloy to initiation of localized corrosion. The results of this test are not intended to correlate in a quantitative manner with the rate of propagation that one might observe in service when localized corrosion occurs.3.2 In general, once initiated, localized corrosion can propagate at some potential more electropositive than that at which the hysteresis loop is completed. In this test method, the potential at which the hysteresis loop is completed is determined at a fixed scan rate. In these cases, the more electropositive the potential at which the hysteresis loop is completed the less likely it is that localized corrosion will occur.3.3 If followed, this test method will provide cyclic potentiodynamic anodic polarization measurements that will reproduce data developed at other times in other laboratories using this test method for the two specified alloys discussed in 3.4. The procedure is used for iron-, nickel-, or cobalt-based alloys in a chloride environment.3.4 A standard potentiodynamic polarization plot is included. These reference data are based on the results from five different laboratories that followed the standard procedure, using specific alloys of Type 304 stainless steel, UNS S30400 and Alloy C-276, UNS N10276.3 Curves are included which have been constructed using statistical analysis to indicate the acceptable range of polarization curves.3.5 The availability of a standard test method, standard material, and standard plots should make it easy for an investigator to check his techniques to evaluate susceptibility to localized corrosion.1.1 This test method covers a procedure for conducting cyclic potentiodynamic polarization measurements to determine relative susceptibility to localized corrosion (pitting and crevice corrosion) for iron-, nickel-, or cobalt-based alloys in a chloride environment. This test method also describes an experimental procedure which can be used to check one's experimental technique and instrumentation.1.2 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 702元 加购物车

定价： 646元 加购物车

定价： 646元 加购物车

定价： 571元 加购物车

定价： 646元 加购物车

定价： 646元 加购物车

定价： 646元 加购物车

定价： 571元 加购物车

定价： 515元 加购物车

4.1 Different electroplating systems can be corroded under the same conditions for the same length of time. Differences in the average values of the radius or half-width or of penetration into an underlying metal layer are significant measures of the relative corrosion resistance of the systems. Thus, if the pit radii are substantially higher on samples with a given electroplating system, when compared to other systems, a tendency for earlier failure of the former by formation of visible pits is indicated. If penetration into the semi-bright nickel layer is substantially higher, a tendency for earlier failure by corrosion of basis metal is evident.1.1 This test method provides a means for measuring the average dimensions and number of corrosion sites in an electroplated decorative nickel plus chromium or copper plus nickel plus chromium coating on steel after the coating has been subjected to corrosion tests. This test method is useful for comparing the relative corrosion resistances of different electroplating systems and for comparing the relative corrosivities of different corrosive environments. The numbers and sizes of corrosion sites are related to deterioration of appearance. Penetration of the electroplated coatings leads to appearance of basis metal corrosion products.1.2 The values stated in SI units are to be regarded as the 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 加购物车

定价： 590元 加购物车

定价： 571元 加购物车

定价： 515元 加购物车

定价： 571元 加购物车