GB/T 33965-2017Metallic materials - Tensile testing - Determination of thickness reduction ratio for rectangular specimens (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009. This standard is proposed by China Iron and Steel Association. This standard by the National Standardization Technical Committee Steel (SAC/TC183) centralized. This standard was drafted. Wuhan Iron and Steel Co., Ltd., Beijing Nonferrous Metal Research Institute, Metallurgical Industry Information Standards Institute, Shanghai Shen Li Tester Co., Ltd., China Southern Airlines Industries (Group) Co., Ltd., Guangzhou Automobile Group Co., Ltd. The main drafters of this standard. Li Rongfeng, Liu Dong, Zhang Hongju, Dong Li, Du Li Ying, Tu Ying Wang, Yang Haoyuan, Liu Shanqing, Liu Kehui, Yuan Huanquan. Tensile test of metallic materials Determination of the thinning rate of rectangular specimens

1 Scope

China's national method for measuring the thickness reduction ratio of a rectangular tensile specimen. It specifies the terms and definitions, the symbols, the test principle, the equipment, the specimens, the procedure, the calculation of results and the test report, and it applies to sheet metal; the thickness reduction of metal tubes may also be measured by reference to it. The familiar measure of ductility from a tensile test is the reduction of area at the fracture, and for a round specimen it is easy: measure the diameter of the neck. For a rectangular specimen cut from sheet it is not, because the neck is not a circle and the cross-section after fracture is neither rectangular nor regular. Measuring the thickness alone, at the fracture, gives a number that can be obtained consistently, and it is the quantity that matters for sheet metal in any case: what limits a stamping is how far the sheet can thin before it splits. Fixing how that measurement is made is what allows two laboratories, or a supplier and a press shop, to agree on a formability figure.

This standard specifies the terms and definitions, symbols and instructions, test principle, Test equipment, samples, test procedures, calculation of test results and test reports. This standard applies to the determination of the thickness of the sheet metal tensile test rectangular thinning rate. Metal pipe thickness reduction rate can also be measured Refer to this standard.

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated version applies to this document. For undated references, the latest edition (including all amendments) applies to this document. Tensile testing of metallic materials - Part 1. Test methods at room temperature

GB/T 228.2 Tensile testing of metallic materials - Part 2. High temperature test methods

GB/T 5027 metal sheet and thin strip plastic strain ratio (r value) determination

GB/T 5028 Metallic materials - Determination of tensile strain hardening index (n value) of sheets and strips Calibration of extensometers for uniaxial testing

GB/T 13239 low temperature tensile test methods for metallic materials

GB/T 16825.1 static uniaxial testing machine test Part 1. Tensile and (or) pressure testing machine testing system and force measurement calibration

GB/T 30069.2 Metallic materials - High strain rate tensile test - Part 2. Hydraulic servo and other test systems

3 Terms and definitions

The following terms and definitions apply to this document.

3.1 Thinning rate percentageofthicknessreduction The percentage of the change in the thickness of the sample to the original thickness. See equation (1). eta = a0-a a0 × 100% (1)

3.2 Maximum plasticity reduction rate percentageofplasticthicknessreductionatmaximumforce etag The percentage of the ratio of the amount of plastic reduction in the thickness direction to the original thickness at maximum force. See equation (2).