1.1 本试验方法包括弯曲试验，以验证钢板上的金属涂层没有分层。所述试验方法设计用于实验室和工厂环境。 1.2 金属涂层钢产品应符合以下适当规范的所有要求:规范 A463/A463M , A653/A653M , A755/A755M , A792/A792M , A875/A875M , A924/A924M , A929/A929M , A1046/A1046M , A1057/A1057M , A1063/A1063M , A1079号 和 A1087/A1087M . 1.3 数量限制未得到解决，而是在一般要求或单个产品规范或两者中建立；或在适用时，由供应商和用户商定。 1.4 单位- 本规范适用于英寸-磅单位或国际单位制的订单。英寸-磅和国际单位制的数值不一定相等。 在本文中，国际单位制显示在括号中。每个系统应独立使用。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户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（TBT）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》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 本试验方法提供了一种标准方法来弯曲产品，以验证金属表面是否有良好的涂层，附着力是否无分层- 由买方在采购订单或合同中指定的ASTM委员会A05及其子委员会管辖的涂层钢板产品。 4.1.1 金属涂层试件围绕越来越多的金属厚度弯曲180°，终点为不再发生故障。每次弯曲后，在不放大的情况下检查弯曲区域，以确定涂层断裂和附着力损失。 4.1.2 如果需要，可以通过在弯曲后进行胶带拉脱测试来确定粘附力损失或拾取的进一步检查。 4.1.3 测试时的材料条件、采样频率、试样位置和方向、不出现分层或脱落的最小t形弯管额定值、报告要求和其他测试参数包含在相关材料规范或特定产品形式的一般要求规范中。 参考适当的ASTM标准。 4.2 为了使该测试方法能够成功评估涂层附着力，金属基材必须能够承受弯曲操作而不会破裂。 4.3 涂层附着力是金属涂层钢板产品的一个重要质量特征。本试验方法采用参考产品标准中规定的相关t形弯管额定值，以快速确定弯曲试样外部的金属涂层是否无分层。这对于确定产品是否符合规范至关重要。 4.4 本试验方法与试验方法相似，并使用了一些与试验方法相同的仪器 D4145 ，它确定了金属基材上有机涂层（油漆）的柔韧性和附着力的t形弯曲额定值。 4.5 该测试方法可由其他ASTM委员会和其他标准编写机构用于一致性测试。

1.1 This test method covers a bend test to verify that metallic coatings on steel sheet are free of delamination. The test method described is designed and intended for use in both laboratory and plant situations and their environments. 1.2 The metallic-coated steel product shall conform to all the requirements of the appropriate specifications as follows: Specifications A463/A463M , A653/A653M , A755/A755M , A792/A792M , A875/A875M , A924/A924M , A929/A929M , A1046/A1046M , A1057/A1057M , A1063/A1063M , A1079 , and A1087/A1087M . 1.3 Quantitative limits are not addressed and are established in the general requirements, or individual product specifications, or both; or when applicable, as agreed to between supplier and user. 1.4 Units— This specification is applicable to orders in either inch-pound units or SI units. Values in inch-pound and SI units are not necessarily equivalent. Within the text, SI units are shown in brackets. Each system shall be used independently of the other. 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 This test method provides a standard method to bend the product to verify good coating, adhesion free of delamination, on metallic-coated steel sheet products under the jurisdiction of ASTM Committee A05 and its subcommittees as designated by a purchaser in a purchase order or contract. 4.1.1 Metallic coated coupons are bent 180° around progressively more thicknesses of metal, the end point being when failures no longer occur. The bend area is examined without magnification after each bend in order to determine coating fracture and loss of adhesion. 4.1.2 If desired, further examination of loss of adhesion or pickoff can be determined by performing a tape pull-off test subsequent to bending. 4.1.3 The material condition at the time of testing, sampling frequency, specimen location and orientation, minimum t-bend rating exhibiting no delamination or pick-off, reporting requirements, and other test parameters are contained in the pertinent material specification or in a general requirement specification for the particular product form. References are provided to the appropriate ASTM standards. 4.2 For this test method to successfully evaluate coating adhesion, the metal substrate must be capable of withstanding the bending operation without fracturing. 4.3 Coating adhesion is a significant quality characteristic of metallic coated steel sheet products. This test method employs the relevant t-bend rating specified in the referenced product standards to quickly determine if the metallic coating is free of delamination on the outside of a bend specimen. This is critical in ascertaining product conformance to specifications. 4.4 This test method is similar to, and uses some of the same apparatus as, Test Method D4145 , which determines a t-bend rating for flexibility and adhesion of organic coatings (paints) on metallic substrates. 4.5 This test method may be used by other ASTM Committees and other standards writing bodies for the purpose of conformance testing.