residual elements
1.Abstract: This paper discusses briefly the behavior of residual elements in steel and their effect on property of steel.The contents include:the source of residual elements in steel;solidification segregation or grain boundary segregation of residual elements during casting or heat treatment;the effect of residual elements on the surface hot-shortness,the second temper brittleness,the corrosion resistance,strain aging and inhibition on grain growth.At last,it is pointed out that the production clean steel should be one of important projects for China Steel Industry in the future.
3.With growth of EAF steelmaking,and limited aVailability and high price of low residual scrap,the electric furnace melt shop operators must use the maximum amount of lowest cost and poor-quality scrap,while staying within the given steel tolerance for residual deleterious elements. Therefore the process of obsolete scrap mixed and diluted with direct reduced iron（DRI） to produce high-quality steel has been developed and the world production of DRI has steadily increased．
6.It has been already verified that the dcmestic T91 stedl tube is subject oreep bittleness tendency. This paper rpplies tho TEM rnd SEM observation methods to make a microstructural analysis of the residual sample. The research results indicate that the creep bittleness tendency of dsmestic T91 steel tube is related to the reduction of slioing dislocrtion density, ccrrsening of carbide, and biased accumulation of etrimental elements such Sb, Bi, etc.
8.In the paper chemical forms of ten elements (Cu, Pb, Zn, Fe, Mn, Al, Si, Ba, Be and Cr) in Hanjiang River estuary and Shantcu Port have been studied using the sequential extraction procedure. The chemical forms wore, the exchangeable, the carbonates bound, the Fe-Mn oxides bound, the organic and the residual form.
