Coupling between Welding Conditions and Thermal Cycling for Identification of the Mechanical Heterogeneity of a Weld Joint

Abstract

The analyses device safety subject to pressure is based on the prediction at break junctions used for the design of this type of devices. The harmfulness analysis of existing defects on these devices makes indispensable the study of the rupture in these components. Various characterization tests (tensile tests, fatigue tests and tensile strength tests) were carried out at room and low temperatures on plates welded end to end and for the different directions of sampling.An estimate of the toughness in the three areas of a weld joint was made by passing from resilience to toughness in the ductile-brittle transition zone of materials. The temperature range of the tests was to provide measurements of the toughness the lower bearing to the beginning of the transition curve. The purpose of this work is to study the state both mechanical and microstructural aspects of the welded junction. The diagnoses used made it possible to deduce that the small thickness of the HAZ, makes the machining of the specimen difficult. Thereby, a mechanical simulation of the HAZ by registration of the thermal cycle that this area undergoes was necessary to be able to reproduce it and compare it with the actual HAZ.