Neutron residual stress analysis for multiphase materials with depth gradients of the strain free / independent lattice parameter D0

具有无应变/独立晶格参数 D0 深度梯度的多相材料的中子残余应力分析

• 批准号: 282874578
• 负责人: Dr.-Ing. Jens Gibmeier
• 金额: --
• 依托单位: Institut für Angewandte Materialien - Werkstoffkunde (IAM-WK)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/282874578?language=en
• 关键词: Neutron; residual; stress; analysis; multiphase

The aim of the research project for the continuation period remains unchanged and covers the investigation on the influence of phase-specific micro residual stresses on the determination of the reference lattice parameter D0 for coarse multi-phase materials and to provide appropriate measuring and evaluation strategies. For non-destructive analysis of residual stress depths gradients using neutron diffraction the knowledge of this reference value is of high importance. Hereby, the focus is on the realization of neutron through surface strain scans by using very small depth increments with the particular aim to determine residual stress depth distributions non-destructively that are very close to the surface. Here, the prediction and the correction of the surface effects and the associated spurious strains are of vital importance. In the first funding period fundamental investigation on the development of phase-specific residual stresses for coarse two-phase duplex steels have been carried out. The results indicate that phase-specific textures have an immense impact on the development of phase-specific (residual) stresses and strongly affect the analyses. Moreover, it was shown that the fundamental understanding of the micromechanical processes in the materials volume at elasto-plastic materials loading is of enormous importance for the understanding of residual stress development and particularly for the correct residual stress evaluation and for the assessment of the results. Intergranular strains bring out highly non-linear relationships between the diffraction based determined {hkl} dependent lattice strains and the mechanical materials loading. Within the scope of the project continuation a self-consistent material model for the numeric prediction of the plastic anisotropy effects will be formulated and extended to the application on coarse two-phase, textured duplex steels. For the validation of the model and for the assessment of grain orientation dependent strains and stresses supplementary phase-specific strain polefigures will be determined using neutron diffraction. Furthermore, the further development of the simulation routine SIMRES for calculating spurious strains caused by the surface effects during through surface neutron strain scanning will be subject of future investigations. In the continuation project the existing model will be extended to be able to handle also phase-specific textures and texture gradients as well as chemical gradients (D0-Gradients). These enhancements of the simulation software will be realized in close collaboration with our Czech partner J. Šaroun. Finally, at the end of the project period the residual stress analyses carried out for the mechanically surface treated duplex steels and the case hardened stated will be re-evaluated using the implemented software enhancements and the final results will be compared with residual stress distributions that are determined using complementary methods.

继续期间的研究项目的目的保持不变，包括研究相特定的微观残余应力对确定粗大多相材料的参考晶格参数D0的影响，并提供适当的测量和评估策略。对于用中子衍射法对残余应力深度梯度进行无损分析，了解该参考值是非常重要的。因此，重点是通过使用非常小的深度增量来实现通过表面应变扫描来实现中子，其特定目的是非破坏性地确定非常接近表面的残余应力深度分布。在这里，表面效应和相关的虚假应变的预测和校正是至关重要的。在第一个资助期，对粗大双相双相钢的相态残余应力的发展进行了基础性研究。结果表明，相特定织构对相特定(残余)应力的发展有很大的影响，并且对分析有很大的影响。此外，对弹塑性材料加载时材料体积内的细观力学过程的基本了解对于了解残余应力的发展，特别是对于正确的残余应力评估和结果的评估具有重要意义。晶间应变导致基于衍射的依赖于{hkl}的晶格应变与材料的机械载荷之间存在高度的非线性关系。在项目继续的范围内，将建立用于塑性各向异性效应的数值预测的自洽材料模型，并将其扩展到粗大的双相织构双相钢的应用。为了验证模型和评估颗粒取向相关的应变和应力，将使用中子衍射法确定补充的相特定应变极化值。此外，进一步开发模拟程序SIMRES，以计算穿透表面中子应变扫描过程中表面效应引起的虚假应变，将是未来研究的主题。在延续项目中，现有模型将扩展到能够处理特定阶段的纹理和纹理梯度以及化学梯度(D0-梯度)。模拟软件的这些增强功能将在我们的捷克合作伙伴J.ŠAoun的密切合作下实现。最后，在项目期结束时，将使用实施的软件增强功能重新评估对经过机械表面处理的双相钢和表面硬化状态进行的残余应力分析，并将最终结果与使用互补方法确定的残余应力分布进行比较。

项目成果

Neutronographic Analysis of Load Partitioning and Micro Residual Stress Development in Duplex Stainless Steels

双相不锈钢中载荷分配和微观残余应力发展的中子学分析

• DOI: 10.3390/cryst12101378
• 发表时间: 2022
• 期刊: Crystals
• 影响因子: 2.7
• 作者: S. Pulvermacher;T. Pirling;S. Cabeza;M. G. Zuern;M. Hofmann;J. Gibmeier
• 通讯作者: J. Gibmeier

Fast neutron surface strain scanning with high spatial resolution

具有高空间分辨率的快速中子表面应变扫描

• DOI: 10.1016/j.matchar.2019.05.031
• 发表时间: 2019
• 期刊: Materials Characterization
• 影响因子: 4.7
• 作者: J. Rebelo Kornmeier;M. Hofmann;V. Luzin;J. Gibmeier;J. Šaroun
• 通讯作者: J. Šaroun

Sensitivity of reference stress-free values in welds residual stress calculation

• DOI: 10.1016/j.msea.2020.139680
• 发表时间: 2020-07
• 期刊: Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
• 影响因子: 6.4
• 作者: J. Kornmeier;M. Hofmann;J. Gibmeier;C. Truman

Non-destructive Neutron Surface Residual Stress Analysis

无损中子表面残余应力分析

• DOI: 10.1007/s10921-019-0617-2
• 发表时间: 2019
• 期刊: Journal of Nondestructive Evaluation
• 影响因子: 2.8
• 作者: J. Rebelo Kornmeier;M. Hofmann;W. M. Gan;J. Gibmeier;J. Šaroun
• 通讯作者: J. Šaroun

The influence of coverage for high frequency mechanical impact treatment of different steel grades

• DOI: 10.1016/j.jmatprotec.2019.116437
• 发表时间: 2020-03
• 期刊: Journal of Materials Processing Technology
• 影响因子: 6.3
• 作者: J. Schubnell;C. Eichheimer;C. Ernould;A. Maciolek;J. Rebelo-Kornmeier;M. Farajian