This topic introduces the methods of irons, steels and cast irons production. It also describes the structure, properties and the usage of irons, steels and cast irons in the engineering field.
Billet defects pinhole and blowhole formation prevention and evolutionJorge Madias
Pin holes as a surface defect, and blow holes as an inner defect, occur in billet / bloom / beam blank casting, particularly for Si-Mn killed steel cast with metering nozzle and oil lubrication. If they are present in abundance or have a large size, they may originate defects in the rolled products. Their characteristics, factors behind their formation, as well as usual processing conditions that promote their occurrence are discussed. Finally, the evolution of these defects during reheating and rolling is analyzed, with industrial examples
This topic introduces the methods of irons, steels and cast irons production. It also describes the structure, properties and the usage of irons, steels and cast irons in the engineering field.
Billet defects pinhole and blowhole formation prevention and evolutionJorge Madias
Pin holes as a surface defect, and blow holes as an inner defect, occur in billet / bloom / beam blank casting, particularly for Si-Mn killed steel cast with metering nozzle and oil lubrication. If they are present in abundance or have a large size, they may originate defects in the rolled products. Their characteristics, factors behind their formation, as well as usual processing conditions that promote their occurrence are discussed. Finally, the evolution of these defects during reheating and rolling is analyzed, with industrial examples
Because of the rapid depletion of easily processed iron ores, the utilization of refractory ores has attracted increasing attention .
There several billion tonnes iron deposits, and most are refractory ores, which are difficult to process by conventional methods because of the low iron grade, fine grain size and complex mineralogy.
The beneficiation of low-grade iron ores to meet the growing demand for iron and steel is an important research topic.
At present, magnetization roasting followed by magnetic separation is one of the most effective technologies for the beneficiation of refractory iron ores.
However, certain ores do not qualify to be treated in physical separation processes, and hence, alternative strategies are being looked into for upgrading their iron content.
Reduction roasting has many advantages over the physical beneficiation process, such as enhanced iron recovery and processing of complex and poorly liberated iron ores.
The objective of this presentation is to compile and amalgamate the crucial information regarding the beneficiation of low-grade iron ores using carbothermic reduction followed by magnetic separation, which is a promising technique to treat iron ores with complex mineralogy and liberation issues.
Reduction roasting studies done for different types low-grade iron ores including oolitic iron ores, banded iron ores, iron ore slimes and tailings, and industrial wastes have been discussed.
Reduction roasting followed by magnetic separation is a promising method to recover the iron values from low-grade iron ores.
The process involves the reduction of the goethite and hematite phases to magnetite, which can subsequently be recovered using a low-intensity magnetic separation unit.
The large-scale technological advancements in reduction roasting and the possibilities of the application of alternative reductants as substitutes for coal have also been highlighted.
Because of the rapid depletion of easily processed iron ores, the utilization of refractory ores has attracted increasing attention .
There several billion tonnes iron deposits, and most are refractory ores, which are difficult to process by conventional methods because of the low iron grade, fine grain size and complex mineralogy.
The beneficiation of low-grade iron ores to meet the growing demand for iron and steel is an important research topic.
At present, magnetization roasting followed by magnetic separation is one of the most effective technologies for the beneficiation of refractory iron ores.
However, certain ores do not qualify to be treated in physical separation processes, and hence, alternative strategies are being looked into for upgrading their iron content.
Reduction roasting has many advantages over the physical beneficiation process, such as enhanced iron recovery and processing of complex and poorly liberated iron ores.
The objective of this presentation is to compile and amalgamate the crucial information regarding the beneficiation of low-grade iron ores using carbothermic reduction followed by magnetic separation, which is a promising technique to treat iron ores with complex mineralogy and liberation issues.
Reduction roasting studies done for different types low-grade iron ores including oolitic iron ores, banded iron ores, iron ore slimes and tailings, and industrial wastes have been discussed.
Reduction roasting followed by magnetic separation is a promising method to recover the iron values from low-grade iron ores.
The process involves the reduction of the goethite and hematite phases to magnetite, which can subsequently be recovered using a low-intensity magnetic separation unit.
The large-scale technological advancements in reduction roasting and the possibilities of the application of alternative reductants as substitutes for coal have also been highlighted.
8. 記憶力
high on off low
先從C1處加入high訊號 on
off
→T2 ON、T4 Off
這也表示C2接地（low訊號）
→T3 ON、T1 Off
現在，即使撤走原先在C1處的high訊號，也不會有任何的影響，
現在，即使撤走原先在C1處的high訊號，也不會有任何的影響，
而且C1的邏輯狀態，總是能夠一直保持著記憶力。
而且C1的邏輯狀態，總是能夠一直保持著記憶力。
圖 5-1 一位元的SRAM電路
8
9. 讀寫能力
on on
• 栓鎖狀態：位址線low
→ T5 Off、T6 Off
• 讀寫狀態：位址線high
→ T5 ON、T6 ON
high
其中
寫入狀態：位址線high，然後將設定值送到位元線B。
寫入狀態：位址線high，然後將設定值送到位元線B。
讀取狀態：位址線high，然後偵測位元線B的訊號。
讀取狀態：位址線high，然後偵測位元線B的訊號。
圖 5-1 一位元的SRAM電路
9
