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Evolution of microstructure and residual stress under various vibration modes in 304 stainless steel welds.

Hsieh CC, Wang PS, Wang JS, Wu W - ScientificWorldJournal (2014)

Bottom Line: The experimental results indicate that the temperature gradient can be increased, accelerating nucleation and causing grain refinement during this process.A residual stress can obviously be increased, producing an excellent effect on stress relief at a resonant frequency.The stress relief effect with an eccentric circulating vibrator was better than that obtained using a magnetic telescopic vibrator.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 402, Taiwan.

ABSTRACT
Simultaneous vibration welding of 304 stainless steel was carried out with an eccentric circulating vibrator and a magnetic telescopic vibrator at subresonant (362 Hz and 59.3 Hz) and resonant (376 Hz and 60.9 Hz) frequencies. The experimental results indicate that the temperature gradient can be increased, accelerating nucleation and causing grain refinement during this process. During simultaneous vibration welding primary δ -ferrite can be refined and the morphologies of retained δ-ferrite become discontinuous so that δ-ferrite contents decrease. The smallest content of δ-ferrite (5.5%) occurred using the eccentric circulating vibrator. The diffraction intensities decreased and the FWHM widened with both vibration and no vibration. A residual stress can obviously be increased, producing an excellent effect on stress relief at a resonant frequency. The stress relief effect with an eccentric circulating vibrator was better than that obtained using a magnetic telescopic vibrator.

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The simultaneous vibration welding system.
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fig1: The simultaneous vibration welding system.

Mentions: The simultaneous vibration welding of 304 stainless steel was carried out without filler at an arc voltage of 10 V, a welding current of 120 A, and a travel speed of 120 mm/min. Detailed welding parameters are listed in Table 2. The vibrators in this study consisted of an eccentric circulating vibrator (Meta-Lax) and a magnetic telescopic motor (TX-VSR) set up at the welding working table, as shown in Figure 1. The vibration system for a magnetic telescopic motor was used to adjust the vibration controller from the lowest to the highest frequency in order to obtain a resonant frequency, as well as a display of the waveform on the oscilloscope using an accelerometer plus an amplifier. An examination of simultaneous vibration welding, as displayed on the oscilloscope, is shown in Figure 2. The vibration system for an eccentric circulating vibrator measured the amplitude of vibration of the working table using a vibration sensor, which transferred a signal to a Meta-Lax controller. From this process, the spectrum map was obtained from a table drawer, as shown in Figure 3. A spectrum map was constructed according to the x-axis (the opposite amplitude of vibration) and y-axis (vibration frequency), as shown in Figure 4. After the spectrum map was measured, the parameters of the vibration frequencies were selected as being resonant (TX-VSR: 60.9 Hz, Meta-Lax: 376 Hz) or subresonant (TX-VSR: 59.3 Hz, Meta-Lax: 362 Hz). Following this, the simultaneous vibration welding system was started.


Evolution of microstructure and residual stress under various vibration modes in 304 stainless steel welds.

Hsieh CC, Wang PS, Wang JS, Wu W - ScientificWorldJournal (2014)

The simultaneous vibration welding system.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3926365&req=5

fig1: The simultaneous vibration welding system.
Mentions: The simultaneous vibration welding of 304 stainless steel was carried out without filler at an arc voltage of 10 V, a welding current of 120 A, and a travel speed of 120 mm/min. Detailed welding parameters are listed in Table 2. The vibrators in this study consisted of an eccentric circulating vibrator (Meta-Lax) and a magnetic telescopic motor (TX-VSR) set up at the welding working table, as shown in Figure 1. The vibration system for a magnetic telescopic motor was used to adjust the vibration controller from the lowest to the highest frequency in order to obtain a resonant frequency, as well as a display of the waveform on the oscilloscope using an accelerometer plus an amplifier. An examination of simultaneous vibration welding, as displayed on the oscilloscope, is shown in Figure 2. The vibration system for an eccentric circulating vibrator measured the amplitude of vibration of the working table using a vibration sensor, which transferred a signal to a Meta-Lax controller. From this process, the spectrum map was obtained from a table drawer, as shown in Figure 3. A spectrum map was constructed according to the x-axis (the opposite amplitude of vibration) and y-axis (vibration frequency), as shown in Figure 4. After the spectrum map was measured, the parameters of the vibration frequencies were selected as being resonant (TX-VSR: 60.9 Hz, Meta-Lax: 376 Hz) or subresonant (TX-VSR: 59.3 Hz, Meta-Lax: 362 Hz). Following this, the simultaneous vibration welding system was started.

Bottom Line: The experimental results indicate that the temperature gradient can be increased, accelerating nucleation and causing grain refinement during this process.A residual stress can obviously be increased, producing an excellent effect on stress relief at a resonant frequency.The stress relief effect with an eccentric circulating vibrator was better than that obtained using a magnetic telescopic vibrator.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 402, Taiwan.

ABSTRACT
Simultaneous vibration welding of 304 stainless steel was carried out with an eccentric circulating vibrator and a magnetic telescopic vibrator at subresonant (362 Hz and 59.3 Hz) and resonant (376 Hz and 60.9 Hz) frequencies. The experimental results indicate that the temperature gradient can be increased, accelerating nucleation and causing grain refinement during this process. During simultaneous vibration welding primary δ -ferrite can be refined and the morphologies of retained δ-ferrite become discontinuous so that δ-ferrite contents decrease. The smallest content of δ-ferrite (5.5%) occurred using the eccentric circulating vibrator. The diffraction intensities decreased and the FWHM widened with both vibration and no vibration. A residual stress can obviously be increased, producing an excellent effect on stress relief at a resonant frequency. The stress relief effect with an eccentric circulating vibrator was better than that obtained using a magnetic telescopic vibrator.

Show MeSH