A PREDICTIVE LAW TO ADDRESS CREEP DAMAGE IN WELDED JOINTS OF 316L(N) STAINLESS STEEL.

The present work investigates creep damage in welded joints of 316 L(N) stainless steel using a local approach in order to define a predictive law for creep fracture. The material of the study is a weld metal deposit aged for 2000 hours at 600°C. Elastic-plastic and creep behaviour were characterised using smooth specimens. Notched specimens were creep tested. Tests were interrupted prior to rupture. These specimens were then calculated by the finite element method. Microstructural observations and EBSD complementary analysis reveals that creep cavities are preferentially located along the austenite grain boundaries. Measurement of intergranular damage on cross sections of notched specimens is conducted to obtain a predictive damage law, which could be used to estimate the lifetime of welded joints. Further mechanical tests on CT and tubular cracked specimens are performed to validate the creep law identified.