简易拉伸装置的设计及其在含氮奥氏体钢中子散射中的应用

Design of simplified tensile tester and its application to neutron scattering of nitrogen bearing austenite steel

结合原位中子小角度散射的实际要求,设计了一种整体结构简单、试样安装方便的U型悬臂式拉伸变形装置。该装置通过导向滑孔与移动滑杆间的耦合来确保实现单向拉伸变形;分别贴于试样平直部位与夹头圆柱部位的应变片组用于获取试样的应力-应变响应。分步拉伸试验表明,塑性变形过程中试样的应力松弛在停止加载后的前200 s最为显著,过后松弛较为缓慢。中子小角散射初步结果表明该装置能满足原位拉伸变形的要求,并在含氮奥氏体钢中纳米偏聚团对材料形变强化过程的影响机制研究中发挥着重要作用。

An easy-setup,simple-structure U-type cantalever tensile tester was developed according to the practical requirement for the in situ small angle neutron scattering.The uniaxial tensile deformation was ensured by the combination between the guiding hole and the modified moving bolt,and two film strain gages were employed to record the real-time strain and stress signals of the investigated sample.The step-by-step tensile deformation showed that the rapid stress relaxation usually takes place within the first 200 s after stopping the uploading,and then the stress relaxation becomes very slow.The primary results of small angle neutron scattering indicated that the above mechanical tester meets well the technical requirement about the in situ tensile deformation.