PROBLEMS RAISED BY NOXES CONTROL AT FCAW
Flux cored arc welding (FCAW) is applied due to its remarkable results and advantages (high productivity, joint quality etc) in various fields (industrial construction, naval, chemistry, petrochemistry etc.). FCAW disadvantages, mainly the emission of pollutants, can be counteracted by their rigorous control and local forced ventilation in the production. Control measures that can be used for measuring “in-situ” noxes resulting from the FCAW process are presented. Case studies are presented as well, containing data regarding two new tubular wire produced in order to be used with the flux cored arc welding process.
Particle size distribution of gas metal and flux cored arc welding fumes
A cascade impactor was employed to separate the fume particles in order to determine the size distribution of welding fume. Clear images of coarse welding fume particles (microspatter) from scanning electron microscopy are presented. The particle size distribution of the welding fume reveals that gas metal arc welding (GMAW) fume consists predominately of particle agglomerates smaller than approximately one micrometer. Less than 10% of the fume by weight is microspatter, which is larger than a micrometer. This fraction of microspatter does not change greatly as the GMAW parameters are changed. Flux cored arc welding (FCAW) fume contains more microspatter, approximately 30% by weight.
Cooperative Collection Development
The author discusses cooperative collection development from an historical perspective and examines some of the projects conceived and implemented during the past forty years. In many cases the projects failed even after years of concentrated effort. However, more important than these failures are new efforts that are being made. The major focus of this article is on both current regional projects and the more broadly based ARL-sponsored North American Collections Inventory Project. The author discusses these efforts and offers some specific judgments regarding the possibility that these projects will lead to a truly successful coordinated collection development project on a national basis.