STP803V2

    An Analysis of Elastic-Plastic Fracture Toughness Behavior for JIc Measurement in the Transition Region

    Published: Jan 1983


      Format Pages Price  
    PDF (732K) 31 $25   ADD TO CART
    Complete Source PDF (15M) 31 $237   ADD TO CART


    Abstract

    Fracture toughness tests were performed in the transition region for ASTM A508 Class 3 and A470 nickel-chromium-molybdenum-vanadium steels using about 300 specimens of 0.5T, 1T, 2T, and 4T compact tension (CT) specimens. The KJ-values which are converted from Jc of the smaller specimens indicated a wide scatter ranging from below the KIc-value to much higher toughness. The fracture behavior was investigated with a scanning electron microscope in detail and the sources of scatter of the toughness in small specimens were studied. The fast brittle fracture behavior in the transition regime can be divided into two regions: (1) the region where fracture occurs on a blunting line (Region I) and (2) the region where fracture occurs on an R-curve (Region II). The scatter of the KJ-values in each region is caused by the amount of crack extension contained in the specimens.

    Methods to obtain the fracture toughness equivalent to the KIc from the KJ-values are presented. In Region I the lowest bound of KJmin-values obtained using specimens that meet the requirement NB ⩾ 3000 JcminY is recommended, and this method may also be used in Region II. In Region II a modified R-curve method is proposed.

    Keywords:

    steels, cleavage fracture, fractures (materials), fracture toughness, J-integral, transition effects, Weibull statistics, specimen size effects, testing technique, elastic plastic fracture


    Author Information:

    Iwadate, T
    Section manager and engineers, Research Laboratory, Muroran Plant and general manager, Material Research Laboratory, The Japan Steel Works, Muroran,

    Tanaka, Y
    Section manager and engineers, Research Laboratory, Muroran Plant and general manager, Material Research Laboratory, The Japan Steel Works, Muroran,

    Ono, S
    Section manager and engineers, Research Laboratory, Muroran Plant and general manager, Material Research Laboratory, The Japan Steel Works, Muroran,

    Watanabe, J
    Section manager and engineers, Research Laboratory, Muroran Plant and general manager, Material Research Laboratory, The Japan Steel Works, Muroran,


    Paper ID: STP36785S

    Committee/Subcommittee: E08.08

    DOI: 10.1520/STP36785S


    CrossRef ASTM International is a member of CrossRef.