Based on the author’s hypothesis that nondestructive examination (NDE) has a major role in predicting the fatigue life of pressure vessels, a project was initiated to develop a defined relationship between NDE and fatigue strength reduction factors (FSRF). Even though a relationship should apply to both base metal and weld metal, the project was limited to weld metal because NDE for base metal is reasonably well established, whereas NDE for weld metal is more variable, depending on application. A matrix of FSRF was developed based on weld type (full penetration, partial penetration, and fillet weld) versus the NDE that is applied. The NDE methods that are included are radiographic testing (RT), ultrasonic testing (UT), magnetic particle testing (MT), dye penetrant testing (PT), and visual testing (VT). The first two methods (RT and UT) are volumetric examinations, and the remaining three are surface examinations. Seven combinations of volumetric and surface examinations were defined; thus, seven levels of FSRF are defined. Following the initial development of the project, a PVRC (Pressure Vessel Research Council) grant was obtained for the purpose of having a broad review. The report (Hechmer, 1998) has been accepted by PVRC. This paper presents the final matrix, the basis for the FSRF, and key definitions for accurate application of the FSRF matrix. A substantial amount of additional information is presented in the PVRC report (Hechmer, 1998).

ASME Code, 1995, Boiler and Pressure Vessel Code, Section III, Rules for Construction Of Nuclear Power Plant Components, NB, Class 1 Components and Section VIII, “Rules for Construction of Pressure Vessels,” Division 2, “Alternate Rules.”
Hechmer, J., 1998, “FSRF for Welds Based on NDE,” PVRC Grant No. 97–22 Report, Welding Research Council, January 26, Welding Research Council Bulletin 432.
Snow, A. L., Langer, B. F., and Gibbons, W. G., 1967, “Low Cycle Fatigue Strength of Notched Ni-Cr-Fe Alloy 600 and Low Alloy Steel,” WAPD-T-2093.
SWC, 1992, Structural Welding Code, ANSI/AWS D1.1-92.
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