Results of EC FP7 Structural Performance of MULTI-METAL Component Project: Dissimilar Metal Welds Fracture Resistance Investigation

Abstract

The purpose of this paper is to disseminate the results of an EURATOM project MULTI-METAL focusing on the structural integrity assessment of dissimilar metal welds. The project started in February 2012 and ended in February 2015. The project is coordinated by VTT with 10 partner organizations from Europe : Technical Research Centre of Finland, Finland (VTT) – Coordinator, AREVA NP, France and Germany (ANP), Commissariat à l’Énergie Atomique et aux energies alternatives, France (CEA), Joint Research Centre of the European Commission, Belgium (JRC), EdF-Energy, United Kingdom (BE), Bay Zoltán Foundation for Applied Research, Hungary (BZF), Electricité de France, France (EDF), TECNATOM, Spain (TEC), Jožef Stefan Institute, Slovenia (JSI), Studsvik Nuclear AB, Sweden (STU). The underlying aim of the project is to provide recommendations for a good practice approach for the integrity assessment (especially testing) of tough dissimilar metal welds as part of overall ductile integrity analyses; this has been presented in the project overview [1]. Experience on typical DMWs concerning manufacturing, residual stresses, flaw assessment and testing have been reviewed. The specimens were taken from mock-ups of welded plates. Three DMWs design variants have been covered: narrow gap DMW with Ni-52, DMW with austenitic steel buttering and a DMW with Nienriched austenitic steel buttering. Mechanical characterization and fracture mechanics testing (CT, SEN(B) and SEN(T) specimens) have been performed. Interpretation of the test has required numerical analysis since the standard ASTM E1820 [2] (CT, SEN(B)) and guidelines dealing with SEN(T) [3][4] are not directly intended to cover DMW. The motivation of the project and its results are generally presented and discussed.

Interface Hardness Analysis of between IN625 and CoCrMo Manufactured by Pulsed Wave Laser Powder Bed Fusion

“…However, the obtained Fe/Al-12Si layers showcased high hardness, characteristic of the FeAl intermetallic [ 30 ]. By leveraging the capabilities of LPBF to combine multiple materials, engineers can create components with tailored erosion-resistant properties, leading to improved durability and reduced maintenance costs in demanding applications [ 4 , 31 , 32 ].…”

“…For example, the acidic liquid flowing in the valves of a chemical plant can easily corrode the valve core, thus requiring special corrosion resistance treatment (Figure 1). Often, multiple components need to be assembled together or additional spraying and strengthening treatment [1][2][3][4]. Conventional techniques aimed at bolstering corrosion resistance, including fusion welding and the application of hot or cold coatings, are often ineffective for long-serving valve components and similar parts when it comes to utilizing dissimilar alloy joining techniques [5][6][7][8].…”

Micromechanical Analysis of In-Plane Constraint Effect on Local Fracture Behavior of Cracks in the Weakest Locations of Dissimilar Metal Welded Joint

“…Only limited studies about the effect of constraint on the local fracture behavior of DMWJ can be found in the literature. Keinanen et al [19] tested the J-resistances of the DMWJ with different constraints, Blouin et al [20] tested a large number of specimens with various types and crack locations at low temperature, and Wang et al [21] studied the ductile crack growth of a DMWJ with different crack depths. More recently, the authors [22,23] investigated the effect of constraint on the local fracture resistances of two cracks which located in the weakest regions of an Alloy52M DMWJ by experiment.…”