Back stress strengthening and strain hardening in gradient structure
Back stress strengthening and strain hardening in gradient structure
复制标题
梯度结构中的背应力强化和应变硬化
DOI：
10.1080/21663831.2016.1153004
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发表时间：
2016-01-01
影响因子：
8.3
通讯作者：
Wu, Xiaolei
中科院分区：
文献类型：
--
作者：
Yang, Muxin;Pan, Yue;Wu, Xiaolei
我们报告了显着的背应力强化和应变硬化梯度结构（GS）无裂纹（IF）钢。背应力是由几何必要位错（GND）堆积引起的长程应力。根据背应力的形成机理，提出了由拉伸卸载-再加载滞回线计算背应力的简单公式和计算方法。梯度结构由于其晶粒尺寸梯度而具有机械不相容性。这会导致应变梯度，需要通过GND来调节。背应力不仅提高了屈服强度，而且显著地增强了应变硬化以增加延展性。冲击声明：梯度结构导致高背应力硬化，以增加强度和延展性。推导了一个物理上合理的方程，用于从卸载/再加载滞后回线计算背应力。图形摘要
We report significant back stress strengthening and strain hardening in gradient structured (GS) interstitial-free (IF) steel. Back stress is long-range stress caused by the pileup of geometrically necessary dislocations (GNDs). A simple equation and a procedure are developed to calculate back stress basing on its formation physics from the tensile unloading–reloading hysteresis loop. The gradient structure has mechanical incompatibility due to its grain size gradient. This induces strain gradient, which needs to be accommodated by GNDs. Back stress not only raises the yield strength but also significantly enhances strain hardening to increase the ductility. Impact Statement: Gradient structure leads to high back stress hardening to increase strength and ductility. A physically sound equation is derived to calculate the back stress from an unloading/reloading hysteresis loop. GRAPHICAL ABSTRACT