Molten Metal High Temperature Corrosion In The Rich Lead Slag Behavior Research

ISA furnace enjoyed a high reputation in the world smelting industry.Its structure compactly, fast response, adaptability, high melting efficiency, Make good use of secondary energy, Comply with environmental requirements. It is one of the most advanced melting furnace in the world. Since the late1990s, it was widely used in the smelting of copper, tin and lead, because of its low investment, high productivity and lower energy consumption. The role of the ISA furnace gun is provided Isa smelting needed for the production of air, oxygen and power of reactive,is the core components of ISA technology.As the core equipment of ISA smelting process, the life of the ISA furnace gun is the most important factor to affect the operating rate of the ISA furnace,also on behalf of one of the technologically advanced degree of Isa smelting technology.In this paper,there is four typical metal materials for the life of lead smelting ISA furnace gun:Ordinary gray iron,310S stainless steel, Inconel625nickel-base superalloy K640cobalt-based cast superalloy,Which hot corrosion in molten lead-rich slag at1150℃were studied.The hot corrosion behavior of four kinds of alloys in melt lead-rich slag at1150℃have been analyzed by Metallographic Microscope,X-ray Diffraction,Scanning Electronic Microscope,Energy Dispersive X-ray analysis,Electron Probe Microanalysis.The hot-corrosion performances of these four alloys have been investigated by the alloy compositon,hot-corrosion dynamics;the products of corrosion layer and elements distribution,meamwhile,the corrosion basis mechanism of four alloys have been discussed in this paper.Result shows that the existence and the distribution patterns of graphite in gray iron in terms of thermodynamics or kinetics have contributed to the corrosion of gray iron by melting lead-rich slag.Also,there is no elements which can generate aprotective compact oxide film (such as:Cr2O3,Al2O3) in gray iron.so the gray iron performance a very poor corrosion resistance in melting lead-rich slag.In the hot corrosion process310S stainless steel alloying elements Cr, Si forming a dense and protective oxide layer on the surface of the metal matrix.And the corrosion product FeCr2O4,NiFe2O4which has a spinel structure can obstruction and reduce the rate of diffusion of iron ions,and improve its oxidation resistance.Fe and Ni were enriched in the metal matrix and hindered Fe,Ni outward diffusion speed which is an important reason for the corrosion resistance of310S stainless steel.Inconel625superalloy element Cr can not form a oxide film with dense,uniform,coverage,well adhesion and protective.Thus, Inconel625superalloy has a poor corrosion resistance,the reason may be due to alloy elements Mo. In the hot corrosion process K640cobalt-based cast superalloy alloying elements Cr, Si forming a dense and protective oxide layer on the surface of the metal matrix.And the corrosion product FeCr2O4, FeCo2O4which has a spinel structure can obstruction and reduce the rate of diffusion of iron ions,and improve its oxidation resistance.Co and Ni were enriched in the metal matrix and hindered Co,Ni outward diffusion speed which is an important reason for the corrosion resistance of K640cobalt-based cast superalloy.In this experimental condition, The hot corrosion resistance of gray iron was the worst. The hot corrosion resistance of Inconel625nickel-based superalloy is generally worse than the310S stainless steel.310S stainless steel and K640cobalt-based cast superalloy are performed well in the early of the hot corrosion.In the late of hot corrosion K640cobalt-based cast superalloy has a better stability. generally The hot corrosion resistance of K640cobalt-based cast superalloy h better than the31OS stainless steel.