You are being redirected because this document is part of your ASTM Compass® subscription.
    This document is part of your ASTM Compass® subscription.

    STP1576

    J-R Curve Determination for Disk-Shaped Compact Specimens Based on the Normalization Method and the Direct Current Potential Drop Technique

    Published: 2014


      Format Pages Price  
    PDF (1.58 MB) 18 $25   ADD TO CART

    Cite this document

    X Add email address send
    X
      .RIS For RefWorks, EndNote, ProCite, Reference Manager, Zoteo, and many others.   .DOCX For Microsoft Word


    Abstract

    Material ductile fracture toughness can be described by J-integral versus crack extension relationship (J-R curve). As a conventional J-R curve measurement method, unloading compliance (UC) becomes impractical in elevated temperature testing because of relaxation of the material and a friction induced back-up shape of the J-R curve. In addition, the UC method may underpredict the crack extension for standard disk-shaped compact (DC(T)) specimens. To address these issues, the normalization method and the dc potential drop (DCPD) technique were applied for determining J-R curves at 24°C and 500°C for 0.18T DC(T) specimens made from type 316L stainless steel. For comparison purpose, the UC method was also applied in 24°C tests. The normalization method was able to yield valid J-R curves in all tests. The J-R curves from the DCPD technique need adjustment to account for the potential drop induced by plastic deformation, crack blunting, etc. and after applying a newly developed DCPD adjustment procedure, the post-adjusted DCPD J-R curves essentially matched J-R curves from the normalization method. In contrast, the UC method underpredicted the crack extension in all tests resulting in substantial deviation in the derived J-R curves manifested by high Jq values than the normalization or DCPD method. Only for the tests where the UC method underpredicted the crack extension by a very small value, J-R curves determined by the UC method were similar to those determined by the normalization or DCPD method.

    Author Information:

    Chen, Xiang
    Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN

    Nanstad, Randy K.
    Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN

    Sokolov, Mikhail A.
    Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN


    Committee/Subcommittee: E10.12

    DOI: 10.1520/STP157620140012