The solidification brittleness temperature range (BTR) and local strain in laser surface melted regions of Type 316L stainless steels were investigated in this study, to make clear the mechanism of solidification cracking in the region. The BTR in laser surface melted regions was estimated by the calculation of its upper and lower limits with using the dendrite growth model for Fe-Cr-Ni system and the thermo-dynamic analysis based on calculated phosphorus concentrations at dendrite boundaries in the melted...
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Theoretical Analysis of Hot Cracking Behavior in Melted Regions of Type 316L Stainless Steels by Laser Surface Melting Treatment for Maintenance to Prevent SCC

Laser welding is one of useful methods in manufacturing processes. However, in welding processes, porosi ties sometimes occur in weld metal. Therefore, it is demanded to establish the method to predict and sup press porosities to make sound joints. Numerical simulation has been developing and become one of availa ble techniques to make it realized. Even so it’s still very difficult to predict its formation with comp te accuracy. In this study, numerical analysis to simulate the behavior of bubbles moving i...
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Numerical Simulation of Bubble Behavior in Molten Metal of Aluminum during Laser Welding Process

Abstract The fusion reactor is expected as a next-generation electric source to resolve electricity shortage. The reduce d activation steel F82H has been considering as the structural material for blanket modules set in fusion reactors. In t he case of welding for the steel, its demanded to minimize the heat affected zone (HAZ). Therefore, laser beam welding ( LBW) has been considering as one of welding methods to construct the modules. The objectives of this investigation are t o clarify the critical cond...
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Study on Applicability of Laser Beam Welding for Reduced Activation Ferritic Steel F82H

Fiber laser welding is expected to be especially useful for the fabrication of ITER test blanket module for fusion reactor components. The objective of this study is to clarify the weldabilit y of the dissimilar butt joint between F82H and SUS316L. The plates 4 mm thick of F82H and SUS31 6L were butt-welded by 4 kW fiber laser welding. In 0.2 mm amount of shift from the abutting su rface to SUS316L side, the weld metal region had a mixed phase where the austenite and the ferri te coexist after welding. Vic...
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Fiber Laser Welding for Dissimilar Butt Joint of Reduced Activation Ferritic Steel / Austenite Stainless Steel

To clarify the effects of residual stress and hardening on intergranular stress corrosion cracking (IGSCC) behavior in welds of low-carbon austenitic stainless steels with surface machining, residual stress and hardness were evaluated by 3-dimentional thermo elastic-plastic analysis and grain boundary sliding behavior was examined using a constant strain rate tensile test. It was revealed that grain boundary sliding occurred in the material at 561K by the tensile test with the numerically simulated t...
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Effect of Residual Stress and Hardening on Grain Boundary Sliding in Welds of Low-carbon Stainless Steels with Surface Machining