In this work several methods including sulphur printing,modified spark spectrum analysis and SPEED-SEM-EDX methods were used to study the morphology,composition and distribution of inclusions in pipeline steel.The pro...In this work several methods including sulphur printing,modified spark spectrum analysis and SPEED-SEM-EDX methods were used to study the morphology,composition and distribution of inclusions in pipeline steel.The procedure for the last-mentioned method includes:metal sample preparation using Selective Potentiostatic Etching by Electrolytic Dissolution (SPEED) together with inclusion observation and detection using SEM-EDX equipment.The results of sulphur printing and spark spectrum analysis showed that there was a well-defined centerline containing relatively high concentrations of sulphur in the steel slab studied in this work.The results of SEM study showed that most inclusions found in the steel samples were globular in morphology,and roughly 2-5 micrometers in size.The inclusions were rich in sulphur and manganese.Some inclusions with a bright globular shape contained Al,Ca,Mn and S,and were likely composed of MnS,CaS and calcium aluminate.It was concluded that sulphur printing is a convenient and inexpensive method for inclusion analysis,Spark Spectrum Analysis provides a complete and self-contained technique for inclusion detection,and the SPEED-SEM-EDX procedure is best suited for in-situ and three-dimensional observation of inclusions.展开更多
Traditionally, fluxes containing calcium fluoride and other additives are used for the treatment of hot metal and molten steel. Recently, magnesium powder or lime-Mg mixture is used more popularly in hot metal desulph...Traditionally, fluxes containing calcium fluoride and other additives are used for the treatment of hot metal and molten steel. Recently, magnesium powder or lime-Mg mixture is used more popularly in hot metal desulphurization. However, the use of calcium fluoride has been restricted due to environmental concerns, and the supply of magnesium is uncertain for the countries, which are short of magnesium resource. For those reasons, calcium aluminate fluxes are a possible alternative to replace slags containing calcium fluoride or magnesium. Calcium aluminate fluxes can be produced from three different raw materials: (1) high-quality bauxite, (2) residuals from aluminum dross treatment processes and (3) waste products from alumina production. Due to the limited amount and high cost associated with high-quality bauxite, the other two sources are preferred based on both economic and environmental considerations. The objective of this paper is to examine the use of waste slags and by-products from the aluminum industry as potential refining fluxes for the steel industry so that waste disposal from the aluminum industry can be reduced with economical and environmental benefits for both industrial sectors.展开更多
文摘In this work several methods including sulphur printing,modified spark spectrum analysis and SPEED-SEM-EDX methods were used to study the morphology,composition and distribution of inclusions in pipeline steel.The procedure for the last-mentioned method includes:metal sample preparation using Selective Potentiostatic Etching by Electrolytic Dissolution (SPEED) together with inclusion observation and detection using SEM-EDX equipment.The results of sulphur printing and spark spectrum analysis showed that there was a well-defined centerline containing relatively high concentrations of sulphur in the steel slab studied in this work.The results of SEM study showed that most inclusions found in the steel samples were globular in morphology,and roughly 2-5 micrometers in size.The inclusions were rich in sulphur and manganese.Some inclusions with a bright globular shape contained Al,Ca,Mn and S,and were likely composed of MnS,CaS and calcium aluminate.It was concluded that sulphur printing is a convenient and inexpensive method for inclusion analysis,Spark Spectrum Analysis provides a complete and self-contained technique for inclusion detection,and the SPEED-SEM-EDX procedure is best suited for in-situ and three-dimensional observation of inclusions.
文摘Traditionally, fluxes containing calcium fluoride and other additives are used for the treatment of hot metal and molten steel. Recently, magnesium powder or lime-Mg mixture is used more popularly in hot metal desulphurization. However, the use of calcium fluoride has been restricted due to environmental concerns, and the supply of magnesium is uncertain for the countries, which are short of magnesium resource. For those reasons, calcium aluminate fluxes are a possible alternative to replace slags containing calcium fluoride or magnesium. Calcium aluminate fluxes can be produced from three different raw materials: (1) high-quality bauxite, (2) residuals from aluminum dross treatment processes and (3) waste products from alumina production. Due to the limited amount and high cost associated with high-quality bauxite, the other two sources are preferred based on both economic and environmental considerations. The objective of this paper is to examine the use of waste slags and by-products from the aluminum industry as potential refining fluxes for the steel industry so that waste disposal from the aluminum industry can be reduced with economical and environmental benefits for both industrial sectors.
