1.1 这些试验方法适用于当与电解质接触并对钢施加电势时，确定涂层与钢基体剥离程度的程序。试样可包括涂层钢管或涂层平板或弯曲钢板。涂覆在钢基材上的涂层应为非金属涂层，且在试验温度下不得显示出流动特性。 1.2 这些试验方法适用于浸泡在电解质浴中的试样或在室温下连接有电解质电池的试样，21 °C至25 °C（70 °F至77 °F），条件。如果需要更高的温度，使用试验方法 G42 . 1.3 这些试验方法适用于极化方法，包括牺牲阳极或整流器施加到钢上的外加电流。 1.4 以国际单位制表示的数值应视为标准。括号中给出的值仅供参考。 1.5 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 4.1 钢上涂层的断裂或漏涂会使基材暴露在潜在的腐蚀池中。当钢通过牺牲阳极或外加电流通过钢的极化进行阴极保护时，漏涂处暴露的钢成为腐蚀池中的阴极。 当电解质是中性或微碱性时，氢氧根离子由氧的还原形成，并且当与来自电解质的合适阳离子配对时，形成碱性溶液。根据这种碱性溶液的强度和碱性化合物的浓度，这种碱性可能会破坏涂层和钢之间的粘附，使涂层与钢剥离。 4.2 阴极电池的电流密度也会影响阴极剥离的程度。阳极处电子浓度产生的电流密度越大，形成的氢氧根离子的数量就越大，从而增加了可用于破坏涂层和钢基体之间粘附的碱度。同样，电解质中氧的浓度将影响在阴极处形成的氢氧根离子的浓度。 4.3 由于这些原因，在进行阴极剥离测试时，测量pH、氧气和电流密度通常是有用的。

1.1 These test methods apply to procedures for determining the degree of disbondment of a coating from a steel substrate when placed in contact with an electrolyte and a potential is applied to the steel. Specimens may include coated steel pipe or coated flat or curved steel plate. The coating applied to the steel substrate shall be non-metallic and shall not show flow characteristics at the test temperature. 1.2 These test methods apply to specimens that are immersed in an electrolyte bath or specimens with an attached electrolyte cell at ambient room temperature, 21 °C to 25 °C (70 °F to 77 °F), conditions. If higher temperatures are required, use Test Method G42 . 1.3 These test methods apply to methods of polarization including sacrificial anodes or impressed current applied to the steel by a rectifier. 1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.5 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. 1.6 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. ====== Significance And Use ====== 4.1 Breaks or holidays in a coating applied over steel exposes the substrate to a potential corrosion cell. When the steel is subjected to cathodic protection by the polarization of the steel via sacrificial anodes or impressed current, the exposed steel at the holiday becomes the cathode in the corrosion cell. When the electrolyte is neutral or slightly alkaline, hydroxyl ions form from the reduction of oxygen and, when paired with a suitable cation from the electrolyte, form an alkaline solution. Depending on the strength of this alkaline solution and the concentration of the alkaline compound, this alkalinity may disrupt the adhesion between the coating and the steel, disbonding the coating from the steel. 4.2 Current density of the cathodic cell also can affect the degree of cathodic disbondment. The greater the current density generated by the concentration of electrons at the anode, the greater the number of hydroxyl ions formed, thus increasing the alkalinity available for disrupting the adhesion between the coating and the steel substrate. Likewise, the concentration of oxygen in the electrolyte will affect the concentration of hydroxyl ions formed at the cathode. 4.3 For these reasons it is often useful to measure pH, oxygen, and current density when conducting a cathodic disbondment test.