1.1 本试验方法包括根据稳态裂纹尖端张开角测定断裂扩展韧性( CTOA公司 )使用落锤撕裂试验（DWTT）型试样。该方法适用于表现出至少85%韧性断裂的铁素体钢 % 根据试验方法测量的剪切面积 E436 -铁素体钢落锤撕裂试验的标准试验方法。本试验方法适用于厚度在6 mm和20 mm之间的铁素体钢。 附件A1 描述了厚度在20 mm至32 mm之间的铁素体钢的测试方法。 1.2 在仪器、试样设计和试验方法方面，本试验方法借鉴了试验方法 E436 API 5L3-管线管道落锤撕裂试验的推荐规程。 1.3 这种试验方法的发展是由钢制高压天然气管道轴向运行裂纹的快速延性断裂止裂设计的需要推动的 ( 1. ) . 2. 目的是开发一种测试，以适合用作轧管机测试的形式表征断裂扩展阻力 ( 2. ) . 传统的夏比试验已被证明不适用于现代高韧性管道钢 ( 1. ) . 该试验方法根据裂纹尖端张开角测量断裂扩展阻力，并用于表征铁素体钢。 1.4 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 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。

1.1 This test method covers the determination of fracture propagation toughness in terms of the steady-state crack-tip-opening angle ( CTOA ) using the drop-weight tear test (DWTT)-type specimen. The method is applicable to ferritic steels that exhibit predominantly ductile fracture with at least 85 % shear area measured according to Test Method E436 - Standard Test Method for Drop-Weight Tear Tests of Ferritic Steels. This test method applies to ferritic steels with thicknesses between 6 mm and 20 mm. Annex A1 describes the method to test ferritic steels with thicknesses between 20 mm to 32 mm. 1.2 In terms of apparatus, specimen design, and test methodology, this test method draws from Test Method E436 and API 5L3 - Recommended Practice for Conducting Drop-Weight Tear Tests on Line Pipe. 1.3 The development of this test method has been driven by the need to design for fast ductile fracture arrest of axial running cracks in steel high-pressure gas pipelines ( 1 ) . 2 The purpose has been to develop a test to characterize fracture propagation resistance in a form suitable for use as a pipe mill test ( 2 ) . The traditional Charpy test has been shown to be inadequate for modern high toughness pipe steels ( 1 ) . This test method measures fracture propagation resistance in terms of crack-tip opening angle, and is used to characterize ferritic steels. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 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.