Creep crack growth behavior of type 308 Cb austenitic stainless steel and its weldment has been studied in the temperature range of 875 to 1075 K under plane stress condition. The creep crack growth (CCG) rate has been correlated with parameters like stress intensity factor, K, net section stress and energy rate line integral C*. Among these parameters C* appears to describe well the CCG rate in both the cases of base metal and weldment. The rupture time tr of the cracked material has been found to be related to the energy rate line integral C*s in the steady-state condition, given by a relation of the type C*s · tr = constant. © 1991 by ASME.

M. Kamaraj

Department of Metallurgical and Materials Engineering

Vellore Margabandhu Radhakrishnan

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Journal of Pressure Vessel Technology, Transactions of the ASME

Experimental investigations have been carried out to study the creep crack growth in types 316, 308 Cb, and 304 L stainless steel in the temperature range of 873-1073 K under plane stress condition. Testings have been carried out with both the base metal and the welded composite joints, because such joints are commonly used in nuclear power industries. Among the various parameters tried to correlate the creep crack growth, the energy rate line integral has been found to give the best description of the crack growth rate. The steady-state energy rate line integral has been found to correlate well with the rupture time. Based on this observation, life estimations are presented for thin components containing various initial defect sizes. © 1991 by ASME.

Journal of Engineering Materials and Technology, Transactions of the ASME

Life estimation of cracked stainless steel components under creep conditions

Investigations have been carried out to study crack growth behaviour in type 304 stainless steel under constant-load creep conditions in the temperature range 550-650°C. At 550 and 600°C the load point deflection rate bears a unique relation to the creep crack growth rate, independent of the load. However, the results at 650°C show that the relation is load dependent. The parameters, stress intensity factor and net section stress, do not describe the crack growth rate well and there is wide scatter. The energy rate line integral C* appears to be applicable at 550 and 600°C but not at 650°C where it gives a systematic segregation of data. On the basis of a phenomenological approach a new parameter is derived which appears to correlate well with the creep crack growth at all the three temperatures investigated. This approach also provides an index which can differentiate between creep brittle and creep ductile materials. © 1987.

Journal	Journal of Pressure Vessel Technology, Transactions of the ASME
ISSN	00949930
Open Access	No