Contaminated Metal Components in Dismantling by Hot Cutting Processes

2006 ◽  
Author(s):  
Franco G. Cesari ◽  
Massimo Rogante ◽  
Angelo Giostri ◽  
Gianmario Conforti
Keyword(s):  
Chemical Composition ◽  
Nuclear Power ◽  
Metal Cutting ◽  
Plate Thickness ◽  
Ferritic Alloys ◽  
Technical Parameters ◽  
Experimental Campaign ◽  
Cutting Rate ◽  
U235 Fission ◽  
Cutting Processes

During the preparatory dismantling activities of Caorso’s Nuclear Power Plant (NPP), an experimental campaign using plasma and oxyacetylene metal cutting processes has been performed and applied to plates and tubes exposed to the coolant steam of the reactor. The plant (Boiling Water Reactor, 870 MWe) was designed and built in the 70s, and it was fully operating by 1981 to 1986 being shut down after 1987 Italy’s poll that abrogated nuclear power based on U235 fission. The campaign concerns no activated materials, even if the analyses have been performed of by use contaminated components under the free release level, not yet taking into account radioactivity. In this paper, the parameters related to inhalable aerosol, solid and volatile residuals production have been, studied during hot processes which applies the same characteristics of the cutting in field for the dismantling programs of Caorso NPP. The technical parameters such as cutting time and cutting rate vs. pipe diameter/thickness/schedule or plate thickness for ferritic alloys and the emissions composition coming from the sectioning are also reported. The results underline the sort of trouble that can emerge in the cutting processes, in particular focusing on the effects comparison between the two cutting processes and the chemical composition of powders captured by filtering the gaseous emission. Some preliminary considerations on methodology to be used during the dismantling have been presented.

scholarly journals Adaptive Particle Finite Element Method (A‐PFEM) in Metal Cutting Processes

PAMM ◽  
2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Xialong Ye ◽  
Juan Manuel Rodríguez Prieto ◽  
Ralf Müller
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Metal Cutting ◽  
Particle Finite Element Method ◽  
Cutting Processes ◽  
Element Method

scholarly journals Investigation of the Cutting Uid'S Ow and its Thermomechanical Effect on the Cutting Zone Based on Uid-Structure Interaction (FSI) Simulation

2021 ◽  
Author(s):  
Hui Liu ◽  
Markus Meurer ◽  
Daniel Schraknepper ◽  
Thomas Bergs
Keyword(s):  
Metal Cutting ◽  
Negative Impact ◽  
Orthogonal Cutting ◽  
Fluid Simulation ◽  
Cutting Fluid ◽  
Cutting Fluids ◽  
Thermomechanical Effect ◽  
Dimensional Simulation ◽  
On Chip ◽  
Cutting Processes

Abstract Cutting fluids are an important part of today's metal cutting processes, especially when machining aerospace alloys. They offer the possibility to extend tool life and improve cutting performance. However, the equipment and handling of cutting fluids also raises manufacturing costs. To reduce the negative impact of the high cost of cutting fluids, cooling systems and strategies are constantly being optimized. In most existing works, the influences of different cooling strategies on the relevant process parameters, such as tool wear, cutting forces, chip breakage, etc., are empirically investigated. Due to the limitations of experimental methods, analysis and modeling of the working mechanism has so far only been carried out at a relatively abstract level. For a better understanding of the mechanism of cutting fluids, a thermal coupled two-dimensional simulation approach for the orthogonal cutting process was developed in this work. This approach is based on the Coupled Eulerian Lagrangian (CEL) method and provides a detailed investigation of the cutting fluid’s impact on chip formation and tool temperature. For model validation, cutting tests were conducted on a broaching machine. The simulation resolved the fluid behavior in the cutting area and showed the distribution of convective cooling on the tool surface. This work demonstrates the potential of CEL based cutting fluid simulation, but also pointed out the shortcomings of this method.

Simulation and Optimization of Metal Cutting Processes in the Automobile Industry

2002 ◽  
Author(s):  
Robert Gabriel ◽  
Klaus Schneider ◽  
Jürgen Stichling ◽  
Jens Hesselbach
Keyword(s):  
Automobile Industry ◽  
Metal Cutting ◽  
Simulation And Optimization ◽  
Cutting Processes

Effect of Large Cross-Section Oxygen-Propane Flame Cutting on Microstructure in Heat-Affected Zone

2013 ◽  
Vol 274 ◽  
pp. 249-252
Author(s):  
Zhi Xin Wang ◽  
Yong Kui Han ◽  
Yong Qiu Chen
Keyword(s):  
Cross Section ◽  
Heat Affected Zone ◽  
Metal Cutting ◽  
Cutting Speed ◽  
Pressure Vessels ◽  
Manufacturing Industries ◽  
Cutting Process ◽  
Pure Oxygen ◽  
Cutting Processes ◽  
34Crnimo6 Steel

Many metal-manufacturing industries include oxyfuel gas cutting among their manufacturing processes because cutting was often used in metal-cutting processes, specifically in the large castings and forgings and the fabrication of pressure vessels. The oxyfuel gas cutting process uses controlled chemical reactions to remove preheated metal by rapid oxidation in a stream of pure oxygen. Previous research has demonstrated microstructure in heat-affected zone varied depending on the gas used for the combustion as well as the cutting speed (Vc) used during the process. In this research, 34CrNiMo6 steel of 900 mm in thickness and 45 carbon steel of 450 mm in thickness were cut using an oxygen-propane flame cutting process. Then, macroscopic morphology and microstructure test were done to analyze the influence of the thickness of cutting cross-section. The results showed, in general, the width of heat-affected zone increased with the thickness of cutting cross-section. Also, it was demonstrated that heat-affected zone in the bottom and top section was wider than others.

Stability Analysis of Finite Difference Model of Orthogonal Metal Cutting in Presence of Random Noises

1999 ◽  
Author(s):  
Alexandra Rodkina ◽  
Marian Wiercigroch
Keyword(s):  
Metal Cutting ◽  
Necessary Conditions ◽  
Random Noise ◽  
Resistance Force ◽  
Stable Operation ◽  
Difference Model ◽  
Single Degree Of Freedom ◽  
Wide Range ◽  
Orthogonal Metal Cutting ◽  
Cutting Processes

Abstract The dynamics of a nonlinear cutting process in the presence of random noise is defined and investigated. This approach is adequate for a wide range of models describing the orthogonal metal cutting processes by a single-degree-of-freedom oscillator, where the nonlinearity comes from the cutting force in form of a variable resistance force. The method of Lyapunov–Krasovskii functional was adopted to analyze the necessary conditions for a stable operation. The conditions ensuring an asymptotic stability in the presence of random noises are established.

Numerical Simulation and Experimental Validation of Pure Water Jet Machining of Ti-6Al-4V

2020 ◽  
Author(s):  
Greg Pasken ◽  
J. Ma ◽  
Muhammad P. Jahan ◽  
Shuting Lei
Keyword(s):  
Predictive Modeling ◽  
Metal Cutting ◽  
Removal Rate ◽  
Pure Water ◽  
Surface Profile ◽  
Predictive Modelling ◽  
Water Jet ◽  
The Other ◽  
Orifice Diameter ◽  
Cutting Processes

Abstract The most common problem when machining titanium using traditional metal cutting processes is that tools rapidly wear out and need to be replaced. This study examines the ability of a pure water jet to machine Ti-6Al-4V via simulations using ABAQUS’s Smoothed Particle Hydrodynamics (SPH). These simulations are then validated experimentally at two pressures, 138 MPa and 317 MPa. Using a Maxiem water jet built by Omax, experiments are conducted by creating a series of 5 lines that are 5 inches (127 mm) long placed 0.5 inches (12.7 mm) apart on a 1 mm thick Ti-6Al-4V workpiece. Predictive modeling is also conducted using the two additional pressures 400 MPa and 621 MPa as well as three orifice diameters 0.254 mm, 0.3556 mm, and 0.4572 mm. The simulations are validated at both pressures and had a percent error less than 2.6% which were within the standard deviation of the experimental results. The predictive modeling indicates that the pressures above 317 MPa create a near identical percent increase from the orifice diameter but the kerf has a more noticeable decrease in width of cut as the pressure increases. The 138 MPa has the smoothest surface profile compared to the other pressures. The volume of removed material decreases as the pressure increases but the material removal rate (MRR) increases as the pressure increases. This is due to the velocity of the water increasing as the pressure increases causing a lower run time. The 621 MPa is the best pressure to machine Ti-6Al-4V as it has a better MRR than the other pressures used in the predictive modelling.

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