Davies, C. M. ; Wimpory, R.C. ; Tabuchi, M. ; Dean, D.W. ; Nikbin, K.M.: The influence of specimen geometry and test times on high temperature crack growth behaviour in parent and welded 316H stainless steel. In: Proceedings of PVP2008 ASME Pressure Vessels and Piping Division Conference July 27-31, 2008, Chicago, Illinois, USA [Ausg. auf CD], 2008, p. 1-9
Abstract:
Experimental crack growth testing has been performed at 550 °C on a range of fracture specimens including sections taken from a 316 steel weldment. These specimens include the compact tension, C(T), and circumferentially cracked notched bar, CCB, geometries of various sizes. Results are presented from two creep crack growth (CCG) tests on a large and a small CCB weldment specimen. The creep crack initiation (CCI) and growth (CCG) behavior of the CCB weldments has been compared to that of homogeneous parent material (PM) CCB and C(T) specimens and to C(T) weldment specimen data. The data has been analyzed in terms of the C* parameter. The initiation period is found to occupy a large fraction of the test duration for weldments. The CCG rates in the larger CCB weldment test is on the order of six times faster, for a given value of C*, compared to the smaller specimen, indicating a specimen size effect. The CCI times are around an order of magnitude greater for the CCB weldment specimens compared to C(T) weldment data and are higher than that of the PM CCB data. It is recommended that further testing on weldment specimens is performed to affirm the apparent trends.