Dilution represents the contribution from base material to weld metal and its important effects are complicated for multi-pass steel welds. In this study, dilution was determined each bead in a 3-pass gas tungsten arc (GTA) corresponding submerged (SA) weld. Different filler materials were used with process, but both cases involved deposition of wires into grooves low-alloy (SA508) ferritic plates. Martensite bainite observed heat-affected zone (HAZ) cases. Acicular ferrite dominated SA...

Weld-induced in-process tempering of martensite/bainite was studied through characterisation and modelling. Three-pass gas tungsten arc (GTA) submerged (SA) welds were produced in grooved plates made from a low-alloy ferritic (SA508) steel. A thermal-metallurgical-mechanical model developed to simulate multi-pass welding while accounting for kinetics. Significant martensite, the heat affected zone that by first pass, occurred during second third passes, resulting coarsened lath structure,...

Welding is an important process used during the construction and maintenance of nuclear reactor components. results in residual stresses, distortions microstructural changes joined components, which can have significant deleterious effects on their in-service performance. It thus crucial for engineers to effectively predict these effects. Ferritic steels undergo solid-state phase transformations (SSPT) heating cooling, making welding simulation challenging. The strains associated with SSPTs...

A thermal-metallurgical-mechanical model was developed to study the effects of dilution in each weld pass for multipass gas tungsten arc and submerged welding low alloy steel (i.e. SA508) plates. Hardness distributions residual stresses were measured on transverse sections perpendicular direction manufactured weldments. The predicted hardness compared with measurement data shown be reasonably accurate. results showed that can significantly affect both stress field metal. It found that, base...

Abstract The high source stability and brightness of field emission gun equipped scanning electron microscopes (SEM) makes them ideal for high‐resolution digital image correlation (HRDIC). However, their initial capital cost can be prohibitive research organisations groups. Conventional thermionic SEMs using either a tungsten hairpin or LaB 6 filament are far more widespread due to lower cost. Whilst it is understood that overall performance ultimate resolution than SEMs, we propose there no...

Abstract Scanning electron microscopy‐based high‐resolution digital image correlation (HRDIC) is now an established technique, providing full‐field strain and displacement measurement at the microscale. Techniques for generating speckle patterns sub‐micron mapping can often be either substrate dependent or rely on applying aggressive conditions which may alter microstructure of interest damage in highly sensitive materials. We detail a modification methodology successfully applied literature...

The European DEMOnstration Fusion Power Plant DEMO represents a significant milestone in the progression towards sustainable fusion energy and critical phase between ITER commercial reactors, aiming to demonstrate sustained net positive electricity production. Thanks its properties, tungsten is promising material for divertor armor. Coupled with copper alloys as heatsinks, they offer robust thermal management properties deal intense thermomechanical loads irradiation damage. Understanding...

Abstract In the European DEMOnstration Fusion Power Plant (DEMO) fusion reactor, in-vessel components face significant thermomechanical loads. They can experience severe damage due to high thermal load cycles, coupled with electromagnetic loading and unprecedented levels of irradiation damage. Cooling fluids are used extract heat reduce operating temperatures for energy production. Other elements, like shielding liner reflector plate supports, may also creep-fatigue To assess...

Abstract A three-pass groove weld made by gas-tungsten arc welding in a 20-mm thick SA508 steel plate is modeled to predict the thermal, metallurgical, and mechanical behavior. The dilution for each pass estimated as proportion of base material metal, based on predicted cross-sectional areas fusion zone (FZ) associated with individual pass. temperature predictions are consistent thermocouple measurement data cross-weld macrographs. microstructures qualitatively compared observed optical...

The current work presents the numerical analysis of solid-state transformation kinetics relating to conventional welding ferritic steels, with aim predicting constituent phases in both fusion zone and heat affected (HAZ) weldment. begins predictions isothermal using thermodynamic principles, such that chemical composition parent metal is sole user-defined input. data then converted anisothermal Scheil-Avrami additive rule, including effects peak temperature austenite grain growth....

Constitutive plasticity theory is commonly applied to the numerical analysis of welds in one three ways: using an isotropic hardening model, a kinematic or mixed isotropic-kinematic model. The choice model not entirely dependent on its accuracy, however, as lack empirical data will often necessitate use specific approach. present paper seeks identify accuracy each formalism through direct comparison predicted and actual post-weld residual stress field developed three-pass 316LN stainless...

Three-pass gas tungsten arc welding in a 20-mm thick SA508 steel plate is modelled using sequentially coupled thermal-metallurgical-mechanical model. The dilution for each pass estimated as the proportion of base material weld metal, based on an analysis cross-sectional area fusion zone. thermal solution model validated thermocouple measurement data and cross-weld macrographs. predicted microstructure qualitatively compared with that observed optical micrographs. measured hardness...