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Abstract: It is realized to systematic analysis of the particulate
size distributions and shape, composition, crystal structure for grade
particles of welding aerosol, for the first time, by means of DMPS
(Differential mobility particle sizer) method and ATEM (Analytical
transmission electron microscopy) method. The distribution functions of
particles of order 10 nm for the E4303 and E5015 electrodes are shown as
Dp1E4303 ～ LN(0.042 mm，1.37)
and Dp1E5015～LN(0.054 mm，1.42)
during welding. The results show that the particles of order 10 nm
follow lognormal distribution and relate to metal vaporizing. The G-P
conversion (Gas to Particle Conversion) process and nucleation mechanism
of 10 nm particles of welding aerosol have been investigated. The
crystal structure of particles of order 10 nm is confirmed as Fe3O4. The
particles of order 10 nm are generated according to the homogeneous form
by way of G-P conversion and its controlling reaction is physical
condensation process of Fe(g)→ Fe(l).The model of particulate nucleation
zone in welding arc is put forward. It is important to analysis G-P
conversion process and nucleation mechanism of welding aerosol particle.
Key words: Welding aerosol G-P conversion Homogeneous
nucleation Model of nucleation zone Welding fume
CLC No: TG421
国家自然科学基金(5860170)和武汉市国际合作研究基金(1320017010121)资助项目.
Received 20020810, received in revised form 20021213
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