AM350不鏽鋼箔片之微電漿銲接與熱處理研究

This investigation included two major parts. The first was to develop the optimal welding parameters and heat treatment conditions for AM350 stainless steel foil welds with a thickness of 0.076mm. The second was to simulate the plasma arc welding process and establish the appropriate welding parameters for AM350 bellow weldments.
Results of this investigation revealed that AM350 foil welds would have the optimum qualities as the peak current and welding speed were fixed at 2.5A and 7.5in/min respectively. The tensile properties of foil
specimens, regardless of their former heat treatment conditions, were determined by the post-heat treatment. The foil weldments without post-heat treatment had the minimum tensile strength, only 100MPa, and the solid-state phase transformation of δ→γwas found to be via massive transformation due to its extremely high cooling rate of
4.52 ×104 °C /sec . The foil specimens subjected to the SCT850 heattreatment before and after welding performed the highest tensile strength of 158MPa, but with a quite low elongation. The elongation of the foil welds would be substantially increased as the aging temperature was raised to 535℃.
For bellow welds, while the peak current was set between 4A and 5A, the shape of the weld pool would appear a continuous circular, which could homogeneously distribute the stress on the welds.