The abnormal corrosion of hot iron ladles was investigated.The performance,the composition and the structure of bricks for hot iron ladles were analyzed.The results show that(1)compared with the alumina-silicon carbid...The abnormal corrosion of hot iron ladles was investigated.The performance,the composition and the structure of bricks for hot iron ladles were analyzed.The results show that(1)compared with the alumina-silicon carbide-carbon bricks for the ladle bottom,those for the ladle wall have more pyrophyllite and the Al2O3 content of 36.32 mass%;their bulk density,apparent porosity and cold compressive strength are lower than the requirement of industry standard;they have poor anti-oxidation performance and are oxidized to form a porous layer during service,which loosens the brick lining structure thus leading to fracture,local wear and structural damage of bricks;(2)without preheating,steel scraps are not completely melted,resulting in slag or steel attachment at the mouth or the bottom of ladles thus increasing damage of ladles;(3)and the residual bricks react with the attached slag to form low melting point phases affecting their hot properties.The refractories for the lining of hot iron ladles must be improved in combination with process changes,not entirely by raw materials replacement to reduce costs.展开更多
This paper establishes a model for the production cost of iron and steel enterprise.The variation rule of the production cost versus the iron/steel ratio for two cases, namely,fixed steel production and a fixed amount...This paper establishes a model for the production cost of iron and steel enterprise.The variation rule of the production cost versus the iron/steel ratio for two cases, namely,fixed steel production and a fixed amount of molten iron,is analyzed,and the concept of a steel scrap threshold price is proposed.According to the analysis results,when the steel scrap unit price exceeds the steel scrap threshold price, an increase in the iron/steel ratio can reduce the production cost,and vice versa.When the gap between the steel scrap unit price and the steel scrap threshold price is relatively large, the impact of the iron/steel ratio on the production cost is more prominent.According to the calculation example,when steel production is fixed （284 358 t/month）and the steel scrap unit price is 263.2 yuan/t more than the steel scrap threshold price,an increase of 0.01 in the iron/steel ratio causes a monthly production cost reduction of approximately 750 000 yuan （2.63 yuan/t）.When the amount of molten iron is fixed （270 425 t/month）and the steel scrap unit price is 140.7 yuan/t more than the threshold price,an increase of 0.01 in the iron/steel ratio causes a monthly production cost reduction of approximately 430 000 yuan （1.5 yuan/t）.The results indicate that iron and steel enterprise should adjust the production strategy in time when the scrap price fluctuates, and then the production cost will be reduced.展开更多
废钢的回收过程中,我们经常遇到种类繁多、类别数量不平衡等问题。鉴于此,本研究基于深度学习,提出了一种废钢检测方法,包括类别平衡策略(Class Balance)和分组采样模块(Multi Group Sampling)。类别平衡策略旨在解决数据集中存在的类...废钢的回收过程中,我们经常遇到种类繁多、类别数量不平衡等问题。鉴于此,本研究基于深度学习,提出了一种废钢检测方法,包括类别平衡策略(Class Balance)和分组采样模块(Multi Group Sampling)。类别平衡策略旨在解决数据集中存在的类别分布不均衡问题,而分组采样模块通过促进形状和大小相似的不同类别废钢之间的相互学习。通过对模型结构和训练流程的优化,该方法在废钢数据集上展现了出色的性能。我们采用rtmdet、yolov5和yolov8进行了一系列对比实验,结果显示本研究提出的策略能够在不同模型上取得更优的废钢图像检测效果,mAP分别提高了3.2%、2.6%和3.1%。本研究的成果为废钢回收处理行业提供了一种新的方案,提升废钢回收的效率和质量,推动废钢回收自动化的发展。展开更多
文摘The abnormal corrosion of hot iron ladles was investigated.The performance,the composition and the structure of bricks for hot iron ladles were analyzed.The results show that(1)compared with the alumina-silicon carbide-carbon bricks for the ladle bottom,those for the ladle wall have more pyrophyllite and the Al2O3 content of 36.32 mass%;their bulk density,apparent porosity and cold compressive strength are lower than the requirement of industry standard;they have poor anti-oxidation performance and are oxidized to form a porous layer during service,which loosens the brick lining structure thus leading to fracture,local wear and structural damage of bricks;(2)without preheating,steel scraps are not completely melted,resulting in slag or steel attachment at the mouth or the bottom of ladles thus increasing damage of ladles;(3)and the residual bricks react with the attached slag to form low melting point phases affecting their hot properties.The refractories for the lining of hot iron ladles must be improved in combination with process changes,not entirely by raw materials replacement to reduce costs.
基金The National Key Technology R&D Program during the 12th Five-Year Plan Period(No.2012BAF10B05)
文摘This paper establishes a model for the production cost of iron and steel enterprise.The variation rule of the production cost versus the iron/steel ratio for two cases, namely,fixed steel production and a fixed amount of molten iron,is analyzed,and the concept of a steel scrap threshold price is proposed.According to the analysis results,when the steel scrap unit price exceeds the steel scrap threshold price, an increase in the iron/steel ratio can reduce the production cost,and vice versa.When the gap between the steel scrap unit price and the steel scrap threshold price is relatively large, the impact of the iron/steel ratio on the production cost is more prominent.According to the calculation example,when steel production is fixed （284 358 t/month）and the steel scrap unit price is 263.2 yuan/t more than the steel scrap threshold price,an increase of 0.01 in the iron/steel ratio causes a monthly production cost reduction of approximately 750 000 yuan （2.63 yuan/t）.When the amount of molten iron is fixed （270 425 t/month）and the steel scrap unit price is 140.7 yuan/t more than the threshold price,an increase of 0.01 in the iron/steel ratio causes a monthly production cost reduction of approximately 430 000 yuan （1.5 yuan/t）.The results indicate that iron and steel enterprise should adjust the production strategy in time when the scrap price fluctuates, and then the production cost will be reduced.
文摘废钢的回收过程中,我们经常遇到种类繁多、类别数量不平衡等问题。鉴于此,本研究基于深度学习,提出了一种废钢检测方法,包括类别平衡策略(Class Balance)和分组采样模块(Multi Group Sampling)。类别平衡策略旨在解决数据集中存在的类别分布不均衡问题,而分组采样模块通过促进形状和大小相似的不同类别废钢之间的相互学习。通过对模型结构和训练流程的优化,该方法在废钢数据集上展现了出色的性能。我们采用rtmdet、yolov5和yolov8进行了一系列对比实验,结果显示本研究提出的策略能够在不同模型上取得更优的废钢图像检测效果,mAP分别提高了3.2%、2.6%和3.1%。本研究的成果为废钢回收处理行业提供了一种新的方案,提升废钢回收的效率和质量,推动废钢回收自动化的发展。
