Measurement of Creep Deformation across Welds in 316H Stainless Steel Using Digital Image Correlation

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• 作者：Y. Sakanashi ; S. Gungor ; A.N . Forsey ; P.J. Bouchard
• 关键词：Digital image correlation ; Creep ; Weld properties ; High temperature ; 316H
• 刊名：Experimental Mechanics
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：57
• 期：2
• 页码：231-244
• 全文大小：2956KB
• 刊物类别：Engineering
• 刊物主题：Continuum Mechanics and Mechanics of Materials; Characterization and Evaluation of Materials; Optics, Lasers, Photonics, Optical Devices; Structural Mechanics; Vibration, Dynamical Systems, Control; C
• 出版者：Springer US
• ISSN：1741-2765
• 卷排序：57

文摘

Spatially resolved measurement of creep deformation across weldments at high temperature cannot be achieved using standard extensometry approaches. In this investigation, a Digital Image Correlation (DIC) based system has been developed for long-term high-temperature creep strain measurement in order to characterise the material deformation behaviour of separate regions of a multi-pass weld. The optical system was sufficiently stable to allow a sequence of photographs to be taken suitable for DIC analysis of creep specimens tested at a temperature of 545 °C for over 2000 h. The images were analysed to produce local creep deformation curves from two cross-weld samples cut from contrasting regions of a multi-pass V-groove weld joining thick-section AISI Type 316H austenitic stainless steel. It is shown that for this weld, the root pass is the weakest region of the structure in creep, most likely due to the large number of thermal cycles it has experienced during the fabrication process. The DIC based measurement method offers improved spatial resolution over conventional methods and greatly reduces the amount of material required for creep characterisation of weldments.