Numerical Simulation and Experimental Analysis of Laser Surface Remelting of AISI 420 Stainless Steel Samples

2008 ◽  
Vol 59 ◽  
pp. 265-268
Author(s):  
Noé Cheung ◽  
M.A. Larosa ◽  
Wislei R.R. Osório ◽  
Maria Clara F. Lerardi ◽  
Amauri Garcia
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Stainless Steel ◽  
Laser Surface ◽  
Temperature Fields ◽  
Operating Parameters ◽  
Laser Machine ◽  
Laser Surface Remelting ◽  
Aisi 420 ◽  
The Finite Difference Method

The aim of this work is to develop a heat transfer mathematical model based on the finite difference method in order to simulate temperature fields in the laser surface remelting process. Convective heat transfer in the remelted pool is taken into account by using the effective thermal conductivity approach. Experiments of laser surface remelting of AISI 420 stainless steel samples were carried out in the present investigation, and numerical simulations were applied for the laser machine operating parameters. The work also encompasses the analysis of microstructural and microhardness variations throughout the resulting treated and unmolten zones.

Numerical Simulation and Experimental Analysis of Laser Surface Remelting of AISI 304 Stainless Steel Samples

2010 ◽  
Vol 636-637 ◽  
pp. 1119-1124
Author(s):  
Noé Cheung ◽  
M.A. Larosa ◽  
Wislei R.R. Osório ◽  
M.S.F Lima ◽  
Maria Clara F. Lerardi ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Stainless Steel ◽  
Laser Surface ◽  
Temperature Fields ◽  
304 Stainless Steel ◽  
Operating Parameters ◽  
Aisi 304 ◽  
Laser Surface Remelting ◽  
304 Austenitic Stainless Steel

The aim of this work is to develop a heat transfer mathematical model based on the finite difference method in order to simulate temperature fields in the laser surface remelting process. Convective heat transfer in the remelted pool is taken into account by using the effective thermal conductivity approach. Experiments of laser surface remelting of AISI 304 austenitic stainless steel samples were carried out in the present investigation, and numerical simulations were applied for the CO2 laser machine operating parameters. The work also encompasses the analysis of microstructural and microhardness variations throughout the resulting treated and unmolten zones. This study permits to conclude that numerical simulation is a useful tool in setting the laser operating parameters, enabling pre-programming of the extent of the treated area.

Numerical and Experimental Analysis of Laser Surface Remelting of Al 9wt% Si Alloy Samples

2008 ◽  
Vol 587-588 ◽  
pp. 721-725
Author(s):  
Noé Cheung ◽  
Kleber A.S. Cruz ◽  
Noman H. Khan ◽  
Amauri Garcia
Keyword(s):  
Heat Transfer ◽  
Numerical Simulations ◽  
Rapid Heating ◽  
Thermal Action ◽  
High Energy ◽  
Laser Surface ◽  
High Energy Density ◽  
Temperature Fields ◽  
Laser Materials ◽  
Laser Surface Remelting

Laser materials processing has been widely applied in industrial processes due to unique precision and very localized thermal action furnished by the laser’s high energy density and power controllability. With the inherent rapid heating and cooling rates to which this surface layer is subjected, this process provides an opportunity to produce different microstructures from that of the bulk metal leading to useful properties. The aim of this work is to develop a heat transfer mathematical model based on the finite difference method in order to simulate temperature fields in the laser surface remelting process. Convective heat transfer in the remelted pool is taken into account by using the effective thermal conductivity approach. Theoretical predictions furnished by previous models from the literature were used for validation of numerical simulations performed with the proposed model. Experiments of laser surface remelting of Al-9 wt pct Si samples was carried out in the present investigation, and numerical simulations was applied for the laser machine operating parameters. The work also encompasses the analysis of microstructural and microhardness variations throughout the resulting treated and unmolten zones.

scholarly journals Experimental and Numerical Examinations of Temperature Distributions along SSF Pin Fins Cast through Semisolid Materials Processing

2019 ◽  
Vol 8 (12) ◽  
pp. 500-503
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Stainless Steel ◽  
Heat Sinks ◽  
Materials Processing ◽  
Length Scale ◽  
Pin Fin ◽  
Temperature Distributions ◽  
Pin Fins ◽  
Enhancing Heat Transfer

Heat sinks or fins stand deployed for enhancing heat transfer. That’s why, planned experiments remain fortified for examining the impacts of SSF pin fin on thermal dispersal concerning constant thermal value 6 W/cm2 . For that five chromel-alumel thermocouples are preferred, above and beyond, SSF pin fins materials of stainless steel and aluminum. As anticipated, for both the stated SSF pin fins, temperature declines for increasing length scale. Besides, both results are comparable with each other. However, temperature distributions over SSF aluminum pin fin declines relatively at faster rate comparable to that over SSF stainless steel pin fin. Obviously, it may be owing to higher thermal conductivity of SSF aluminum pin fin. Therefore, it carries superior, pleasant and momentous thermal performances.

scholarly journals Numerical Study of Mixed Convection in a Channel Filled with a Porous Medium

2019 ◽  
Vol 9 (2) ◽  
pp. 211 ◽  
Author(s):  
Filiz Ozgen ◽  
Yasin Varol
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Mixed Convection ◽  
Nuclear Waste ◽  
Numerical Study ◽  
Temperature Fields ◽  
Dimensionless Form ◽  
Geothermal Resources ◽  
Nusselt Numbers ◽  
The Finite Difference Method

The heat transfer of mixed convection in a horizontal channel filled with a porous medium has been studied in this article, given that it plays an extensive role in various technical applications, such as flow of fluid in geothermal resources, formations in chemical industries, the storage of radioactive nuclear waste material, and cooling. Those equations written in a dimensionless form have been solved using the finite difference method for different values of the parameters. The results obtained from the study have been presented through streamlines, isotherms, and both local and average Nusselt numbers. It has been observed that parameters such as the Rayleigh and Peclet numbers have an effect on flow and temperature fields.

Effects of Laser Processing Parameters on Grain Boundary Character Distribution and Corrosion Resistance of Austenite Stainless Steel

2007 ◽  
Vol 561-565 ◽  
pp. 2473-2476 ◽  
Author(s):  
Sen Yang ◽  
Hiroyuki Kokawa ◽  
Zhan Jie Wang
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Laser Processing ◽  
Processing Parameters ◽  
Laser Surface ◽  
304 Stainless Steel ◽  
Grain Boundary Character Distribution ◽  
Grain Boundary Character ◽  
Laser Surface Remelting ◽  
Character Distribution

In order to modify grain boundary character distribution (GBCD) and to improve intergranualr corrosion (IGC) resistance of 304 stainless steel, laser surface remelting experiments were conducted on 304 stainless steel using a 2kW CW Nd: YAG laser, and the effects of laser processing parameters on GBCD and corrosion resistance were investigated in detail under the optimal annealing condition (1220K 28h). The experimental results showed that combination of laser surface remelting and the following annealing treatment could change the GBCD remarkably and improve the IGC resistance of 304 stainless steel. However, there are no obvious effects of laser processing parameters on the final depth of the processed zone, although the depth of the molten pool increases with the increase of the laser output power or the decrease of the scanning velocity, and the subsequent GBCD and corrosion resistance.

Using Porous Fins for Heat Transfer Enhancement

2000 ◽  
Vol 123 (4) ◽  
pp. 790-795 ◽  
Author(s):  
S. Kiwan ◽  
M. A. Al-Nimr
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Performance ◽  
Thermal Conductivity Ratio ◽  
Operating Parameters ◽  
Conductivity Ratio ◽  
Transfer Enhancement ◽  
Porous Fin ◽  
Novel Method ◽  
Porous Fins

This work introduces a novel method that enhances the heat transfer from a given surface by using porous fins. The thermal performance of porous fins is estimated and compared with that of the conventional solid fins. It is found that using porous fin of porosity ε may enhance the performance of an equal size conventional solid fin and, as a result, save 100 ε percent of the fin material. The effect of different design and operating parameters on the porous fin thermal performance is investigated. Examples of these parameters are Ra number, Da number, and thermal conductivity ratio. It is found that more enhancement in the porous fin performance may be achieved as Ra increases especially at large Da numbers. Also, it is found that there is an optimum limit for the thermal conductivity ratio beyond which there is no further improvement in the fin performance.

Thermal treatment effects on laser surface remelting duplex stainless steel

2008 ◽  
Author(s):  
Alex M. do Nascimento ◽  
Maria Clara F. Ierardi ◽  
M. Aparecida Pinto ◽  
Sérgio S. M. Tavares
Keyword(s):  
Stainless Steel ◽  
Thermal Treatment ◽  
Duplex Stainless Steel ◽  
Treatment Effects ◽  
Laser Surface ◽  
Laser Surface Remelting
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