GB/T 5028-2008 in English

《GB/T 5028-2008金属材料 薄板和薄带 拉伸应变硬化指数（n值）的测定》由TC183（全国钢标准化技术委员会）归口，TC183SC4（全国钢标准化技术委员会力学及工艺性能试验方法分会）执行，主管部门为中国钢铁工业协会。
本标准规定了金属薄板和薄带拉伸应变硬化指数（�钪担┑牟舛ǚ椒ā�
本方法仅适用于塑性变形范围内应力�灿Ρ淝�线呈单调连续上升的部分（见７．４）。
如果材料在加工硬化阶段的应力�灿Ρ淝�线呈锯齿状（如某些ＡｌＭｇ 合金呈现出的Ｐｏｒｔｅｖｉｎ��
ＬｅＣｈａｔｅｌｉｅｒ锯齿屈服效应），为使所给出的结果具有一定的重复性，应采用自动测量方法（对真实应力��
真实塑性应变的对数进行线性回归，见７．７）。

Scope

This standard specifies the method for the determination of the tensile strain hardening exponent (n value) of metal sheets and strips. This method is only applicable to the part of the stress-strain curve showing a monotonous continuous rise within the range of plastic deformation (see 7.4). If the stress-strain curve of the material in the work hardening stage is jagged (such as the Portevin-Le Chatelier zigzag yield effect exhibited by some AlMg gold bearings), automatic measurement should be used in order to give a certain reproducibility of the results method (linear regression on the logarithm of true stress - true plastic strain, see 7.7).