A large number of particulate size distributions of welding aerosols are measured by means of DMPS method, several distribution types are presented. Among them the single peak distribution is the basic composing unit...A large number of particulate size distributions of welding aerosols are measured by means of DMPS method, several distribution types are presented. Among them the single peak distribution is the basic composing unit of particulate size. The research on the mathematic models and distributions functions shows that the single peak distribution features the log normal distribution. The diagram estimating method (DEM) is a concise approach to dealing with distribution types, obtaining distribution functions for the particulate sizes of welding aerosols. It proves that the distribution function of particulate size possesses the extending property, being from quantity distribution to volume, as well as high order moment distributions, with K S method verifying the application of single peak distribution and of DEM.展开更多
The effect of heat input on fume and their compositions during gas metal arc welding (GMAW) of AISI 316 stainless steel plates are investigated. Fume generation rate (FGR) and fume percentage were determined by AN...The effect of heat input on fume and their compositions during gas metal arc welding (GMAW) of AISI 316 stainless steel plates are investigated. Fume generation rate (FGR) and fume percentage were determined by ANSI/AWS F1.2 methods. Particle characterization was performed with SEM-XEDS and XRF analysis to reveal the particle morphology and chemical composition of the fume particles. The SEM analysis reveals the morphology of particles having three distinct shapes namely spherical, irregular, and agglomerated. Spherical particles were the most abundant type of individual particle. All the fume particle size falls in the range of less than 100 nm. Mechanical properties (strength, hardness and toughness) and microstructural analysis of the weld deposits were evaluated. It is found that heat input of 1.15 kJ/mm is beneficial to weld stainless steel by GMAW process due to lower level of welding fume emissions and superior mechanical properties of the joints.展开更多
基金theStateNatureScienceFoundation PRC (No :5 860 170 )
文摘A large number of particulate size distributions of welding aerosols are measured by means of DMPS method, several distribution types are presented. Among them the single peak distribution is the basic composing unit of particulate size. The research on the mathematic models and distributions functions shows that the single peak distribution features the log normal distribution. The diagram estimating method (DEM) is a concise approach to dealing with distribution types, obtaining distribution functions for the particulate sizes of welding aerosols. It proves that the distribution function of particulate size possesses the extending property, being from quantity distribution to volume, as well as high order moment distributions, with K S method verifying the application of single peak distribution and of DEM.
文摘The effect of heat input on fume and their compositions during gas metal arc welding (GMAW) of AISI 316 stainless steel plates are investigated. Fume generation rate (FGR) and fume percentage were determined by ANSI/AWS F1.2 methods. Particle characterization was performed with SEM-XEDS and XRF analysis to reveal the particle morphology and chemical composition of the fume particles. The SEM analysis reveals the morphology of particles having three distinct shapes namely spherical, irregular, and agglomerated. Spherical particles were the most abundant type of individual particle. All the fume particle size falls in the range of less than 100 nm. Mechanical properties (strength, hardness and toughness) and microstructural analysis of the weld deposits were evaluated. It is found that heat input of 1.15 kJ/mm is beneficial to weld stainless steel by GMAW process due to lower level of welding fume emissions and superior mechanical properties of the joints.