Study On Environmentally Conscious Mild Steel Flux-cored Wire

The fume's composition and phases of flux-cored wire produced by four different plants were investigated, The results show that the main part of the fume are oxides of the iron and manganese, others are evaporations of the slag. The effect of the iron powder on the fume generation rate (FGR) is also studied, The FGR varies with changes of iron content and has close relation with the property of flux, the FGR declined coupled with the content of the iron powder declining;Iron powders produced by different processes have different shapes,FGR of the sphericity atomization iron powder is higher than the erose deoxidized iron powder;FGR fluctuated orderly in a small scale with the change of the iron powder's granularity distribution, The FGR decreases when the iron powder's granularity is in -210～+130μm(80～120 mesh). The category of the minerals influences on the FGR in the wending materials can be classified three kinds: the first kind include iron,manganese or their alloys and their oxidations is the main composition of the fume, they are the sources of the fume;the second kind inclue arc stabilization materials which can be easily decomposed by high temperature, such as sodium silicon fluoride,sodium aluminum fluoride and other fluorides, they can greatly enhance the wiere's FFR;The third kind include quartz,alumina which have high melting points can lower the FGR and seldom enter into the fume. The effects on the FGR of mineral contents are investigated, the results show that the FGR increases coupled with the increasing of the sodium silicon fluoride content;The flux which the main content is feldspar can greatly lower the FGR, The FGR declines from 8～12g/Kg to 4～4.5g/Kg coupled with the increasing of feldspar content;Ilmenite content has no obvious effects on the FGR;The stability especially the high temperature stability of the mineral powders have great effect on the FGR.Preprocess of the fluxes have different effects on the FGR, Prefused flux can lower the FGR of the flux-cored wire,no obvious effect on FGR is found when the flux is transformed into grains;Reasonable match of mental powders can lower the FGR of flux-cored wire. A kind of environment conscious flux-cored wire which meets National Standard is developed.