In this paper, the practice situation of quick blowing-down and reblowing of 1280m3 blast fur?nace in Jiangyin Xingcheng Special Steel Co., Ltd. is introduced, the operation points and precautions of quick blowing-down and reblowing of blast furnace are expounded, the difficult problems of quick blow?ing-down and reblowing are analyzed, and the recovery situation of furnace condition after reblowing of blast furnace is summarized. The practice has proved that by implementing a series of operation mea?sures, such as canceling the net coke when blast furnace blowing-down and increasing the coke ratio, ac?celerating the slag and iron discharge rate, and increasing the initial air volume during reblowing, the fur?nace condition recovery time of the blast furnace condition after the reblowing is obviously shortened , and the tackle key problems objectives of quick blowing-down and reblowing of 1280m3 blast furnace is achieved. After rapid recovery, the furnace condition of 1280m3 blast furnace is stable and anterograde, and the operation cost of the blast furnace is reduced.
The chain grate machine-rotary kiln is a new process for producing pellet ore, because it can produce high-quality pellet ore to meet the needs of blast furnaces, therefore which is widely used by pellet ore manufacturing enterprise.However, the production process of pellet ore with chain grate machinerotary kiln is complex, and the quality of finished pellet ore is closely related to each production technics and operation, which makes the quality control and adjustment of pellet ore lag behind, and appearing strong periodicity. At present, most pellet ore production enterprises take finished pellet ore samples manually on site for inspection, which makes the pellet ore testing results not real-time guidance for the production process and has a great deal of uncertainty. Therefore, it shows up particularly important to establish the quality prediction algorithm model for the finished pellet ore. The scholars at home and abroad have done a lot of work on the quality prediction algorithm for the pellet ore,there are mainly case-based inference algorithms, neural network-based algorithms, genetic algorithms and other algorithms. In this paper, the pellet ore quality prediction algorithm is analyzed, and the performance of the algorithm and the future development of this field are evaluated and reflected.
Conventional full-hard state cold rolled low carbon steel SPCC products are low in cost and high in hardness, but its mechanical properties cannot be guaranteed, its molding performance is poor,and the risk of processing cracking by users is large, so the use and promotion of products are limited.For this problem, the hardness performance check and bending forming experiment were carried out on the conventional full-hard state cold rolled low carbon steel SPCC products produced by the company,and according to the check and experiment results, the optimized design of the SPCC products production technics was carried out. Through optimizing the chemical composition, hot rolling coiling temperature and cold rolling reduction rate of SPCC products, the surface hardness of full-hard state cold rolled low carbon steel SPCC products can be effectively controlled below 95HRB, the molding performance of products can be improved, and the more complex forming process requirements can be met.
The two high speed wire rod rolling mills of Tiangang High Speed Wire Rod Plant are all imported from American Morgan Company, which mainly produce high-quality carbon structural steel, low alloy steel, alloy structural steel and other high-quality steels, these high-quality steels have highly requirements for surface quality. In order to remove the iron oxide on the surface of red steel billet, a set of high-efficiency high-pressure water descaling system has been installed. The system adopts one driven two control, which can meet the production needs of two high-speed wire rod rolling mills. This paper introduces the technical characteristics, technical scheme, the key points of operation and system protection of the high-efficiency high-pressure water descaling system. The system can realize automatic pressure regulation of descaling high-pressure pump by control of the frequency converter and the PLC,the descaling area ratio is more than 98%, avoids the surface pockmarks and scabs caused by iron oxide, improves the surface quality of the wire rod, and eliminates the quality objection.
A lot of high-temperature flue gas will be produced in the production process of sinter, and the use of this part of the heat for power generation has been included in the national key energy-saving technology promotion project, this is an effective way for iron and steel enterprises to save energy, reduce costs and increase benefits. A steel enterprise has built a 152m~2 step sintering machine, in order to fully recover and utilize the sintering waste heat and reduce the energy consumption of the sintering productive process, it decided to carry out the construction project of power generation by sintering waste heat.This paper introduces the general situation of the 152m~2 step sintering machine in the enterprise, as well as the equipment composition and process flow of the waste heat power generation system, emphatically analyzes the key technologies of deserve attention in the design, construction and operation of the waste heat power generation facilities, and makes a forward-looking discussion on the development of the waste heat power generation of the step sintering machine.
The consumption of solid fuel accounts about for 70%～80%of the total energy consumption in sintering production processes, how to reduce the consumption of solid fuel is the key to reduce the energy consumption of sintering production processes. At present, the consumption of solid fuel of the sintering production processes in Tiangang is 51.49kg/t, compared with the domestic advanced level has a big gap, which has room to tap into their potential. This paper analyzes the main factors that affect the consumption of solid fuel of the sintering production processes in Tiangang, and formulates a series of measures to re?duce the sintering solid fuel consumption with the actual of sintering production and equipment status. Through the implementation of measures such as increasing the thickness of the material layer, reducing the air leakage rate, increasing the material temperature and optimizing the structure of flux, the sintering solid fuel consumption is reduced to 43.36kg/t, and good economic and social benefits are achieved.
There are many kinds of impurities in ferrosilicon with low silicon content, and composition fluctuations is large, which leads to difficult dissolution of the sample, and incomplete dissolution of the sample will lead to inaccurate analysis results of Fe element content in sample. This paper discusses the method of determining Fe element content in ferrosilicon with low silicon content by chemical method,and puts forward a series of improvement measures such as adjusting the dissolution method the sample,optimizing the addition amount of nitric acid and hydrofluoric acid and other. Through the implementation of the improvement measures, the problem that difficult dissolution of the sample has been solved, in addition the potassium dichromate titration method was used to determine the Fe element content in ferrosilicon with low silicon content, which improved the accuracy of the analytical data（analytical deviation 0.50%）. Through tracking data statistics, this method have good stability and reproducibility, it can meet the analysis requirements. At the same time, the method can also be extended and applied to the Fe element content analysis in other alloy materials.
The chemical compositions, microstructure and mechanical properties of the part material of A-pillar lower vertical plate based on a certain car were studied in reverse. The results show that the chemical compositions of the part material conforms to the composition system of dual phase steel, and its microstructure is composed of ferrite and martensite, in which the content of martensite structure is relatively high and fine, and evenly distributed,in terms of mechanical properties,its R p0.2 is 675MPa,Rmis 1027MPa, A 50mm is 10.4%, and its hardness is 340HV10. The stress-strain curve reveals that the steel plate there is no yield extension after stamping. Based on the above various experimental test results, it is determined that the automobile parts material of this time analysis is 980MPa grade dual phase steel.
The basicity stability rate of sinter is directly related to the stability of blast furnace produc?tion, meanwhile also affects various economic and technical indicators of blast furnace. In 2020, after the overhaul of the 360m2 sintering machine of Tianjin Iron and Steel Group Co., Ltd., the output and quality of sinter have been significantly improved，but because the blending ore of the 360m2 sintering machine is directly supplied by the stock yard ingredients room, the stability of the composition of the sintering mixture is poor, and the basicity of the sintered finished ore fluctuates greatly, which has affected the sta?bility of the blast furnace production. This paper analyses the factors affecting sinter basicity stability rate of 360m2 sintering machine, determines the reasons affecting sinter basicity stability rate, and puts forward the process improvement measures. Through the implementation of process measures such as im?proving the stability of raw material and fuel composition, debasing the fluctuation of blending ore compo?sition in the blending batching process, and reducing the basicity fluctuation of the sintering mixture in the sintering batching process, the sinter basicity stability rate of 360m2 sintering machine has been sig?nificantly improved.
The raw materials of iron and steel enterprises will produce a lot of dust pollution during trans?portation. Finding reasonable and effective ways to control these dust can well improve the environmental pollution problem of iron and steel enterprises. This paper analyzes the structural characteristics and ap?plication advantages of the closed semi gantry material warehouse, introduces the design of the dust re?moval measures for the material warehouse and its auxiliary facilities. Raw material yard of iron and steel enterprise adopts closed semi gantry material warehouse design, which can effectively isolate the ware?house working environment from the external environment, and reduce the impact of fugitive dust on the external environment;taking a new type of clean transfer point design can greatly reduce the dust at the transfer point;the design and installation of dust removal equipment in closed semi gantry material ware?house can better improve the environmental quality Inside the material warehouse. The implementation of the above measures has well solved the problem of dust pollution in the material warehouse.
Socketing steel wire rope is widely used in ships, cranes, bridges and other important fields, because of its use environment is complex, therefore there are strict requirements on the breaking force, anti-corrosion and fatigue performance of steel wire rope. Socketing steel wire rope (such as anchor ca?ble) is easy to break at the root of cable joint because of its structural characteristics, in order to find the key factors affecting the breaking load of socketing steel wire rope, the research group carried out scientif?ic analysis and experimental design from two aspects of theoretical calculation and verification test , the factors that affect the fracture load of the casting rigging are truly reflected, and analyzed one by one. This research method effectively eliminates the factors that have little influence on the breaking load of Socketing steel wire rope, and formulates improvement measures for the factors that have great influence.
Based on primary flue gas dust removal technology of the existing converter, several renovation methods to achieve ultra-low emission of the primary flue gas are synthetically narrated,and the path of renovation and upgrading of second times and three times flue gas dust removal is put forward.The existing converter primary flue gas wet dust removal technology（OG method） can achieve ultra-low emission by any of the transformation methods of "OG+ wet process electric dust removal, OG+ high efficiency dust purification separator, OG+ phase change condensing tower + high efficiency mode dust collector, OG+ acoustic agglomeration dust removal". The primary flue gas dry dust removal technology（LT method） can achieve ultra-low emission by any of the transformation methods of "LT + cloth bag dust removal, LT + forward movement of coal gas cooling tower". The second times and three times flue gas can achieve ultra-low emission by "capacity expansion of dust collector and modification of cloth bag ". This paper provides a certain engineering basis and experience for the ultra-low emission transformation of converter flue gas dust removal of iron and steel enterprises.
The method of reducing zinc consumption in hot galvanizing process of steel materials is dis?cussed, and the measures of reducing production amount of zinc slag and zinc ash in hot galvanizing pro?cess, and zinc consumption of the hot galvanized products are emphatically studied. The results show that:for the steel strip, ensuring the surface cleaning, controlling sternly zinc liquid temperature fluctuation and aluminum element content in zinc liquid, selecting reasonably air knife structure and gap, optimizing the travel speed of the steel strip, using nitrogen as the air knife air supply, reducing the leakage plating rate of hot galvanized steel strip and so on, and the zinc consumption can be effectively reduced;for steel pipes and steel structural parts, controlling sternly the drying temperature of steel pipes, optimizing the composition and process parameters of plating aids, controlling the production amount of zinc ash and its zinc content, standardizing the operation process of removing zinc slag, ensuring that the zinc liquid in?side the steel pipes is blown clean, reducing the leakage galvanizing rate of hot galvanized parts, and se?lecting reasonably the capacity of zinc pot and so on, the zinc consumption can be effectively reduced.
The main products of an production enterprise in Tianjin are cold processed stainless steel seamless steel pipes，during organizing the cold processing production of stainless steel seamless steel pipes , the finished steel pipes exist relatively serious quality defects, resulting in a low yield of finished products, which has affected the economic benefits of the enterprise. Therefore measures must be taken to change the quality status of finished pipes. This paper introduces the cold processing technics of stain?less steel seamless steel pipes, analyzes and gathers the quality defects caused by the cold processing procedure of stainless steel seamless pipes, identifies the main factors affecting the quality of steel pipes, and formulates a series of technical and management improvement measures for the key processes of cold processing of steel pipes. Through the implementation of the improvement measures, the quality defects of stainless steel seamless steel pipes are reduced, the yield has be increased, and good quality and eco?nomic benefits have be obtained.
This paper introduces the top system design situation of 1780m~3 blast furnace engineering of relocation project of a steel company in Tangshan, and expounds the main technical features, process equipment,and using effect after putting into production of the top system of this blast furnace. A large number of innovative technologies and advanced equipment have been adopted in the design of the top system of this blast furnace: The furnace top system has adopted PW’s standard tandem bell less top equipment with advanced technology and good performance; the furnace top pressure equalizing and pressure discharging system has adopted the innovative furnace top pressure equalizing gas full recovery technology, which can save a lot of blast furnace gas and reduce the pollution caused by gas emission to the environment; the auxiliary system matched with furnace top equipment has adopted mature, practical and reliable technology and equipment. The application of the above advanced technologies and equipment has created conditions for the high efficiency, low consumption, long life and stable production of the blast furnace.
Air leakage rate of sintering machine pallet is an important measure of sintering machine pro?duction status, which will affect sinter mineralization rate, fuel consumption, sintering cost, sinter unifor?mity etc. Therefore, reducing the air leakage rate of sintering machine pallet is an important link in opti?mizing sintering production. This paper systematically analyses the air leakage problem of the 230m2 sin?tering machine pallet in Tiangang United Special Steel, determines the reason for the high air leakage rate of the sintering machine pallet, and puts forward a series of transformation measures. Through the im?plementation of the regular maintenance system of the sintering machine pallet, the transformation of the pallet slide-way, the improvement of the pallet fence structure , optimization of sintering production pro?cess and other measures, the air leakage rate of sintering machine pallet is reduced from previous about 55%to about 35%, which improves the air permeability of material layer, and reducing fuel consumption, laying the equipment foundation for ultra-thick material layer sintering. At present, the material layer thickness of 230m2 sintering machine in Tiangang United Special Steel has reached 1000mm.
Digital twin technology has been widely used in the field of industrial manufacturing, its key technologies in digital modeling, process computing, data transmission and other have effectively solved the association between the physical world and the digital world, forming the simulated real scene space.As a representative of the process industry, iron and steel manufacturing industry has basically built the enterprise information system architecture to meet the needs of daily production, but the complicated data interaction and the intersection between systems have also become the pain point of the iron and steel enterprises information construction. Through the analysis of the implementation steps and key technologies of digital twin technology, this paper defines its characteristics in the production-manufacturing process, and defines the application points of digital twin technology in iron and steel enterprises through the analysis of the structure of iron and steel enterprises. The practice shows that this technology can effectively improve the data organization and display efficiency of iron and steel enterprises, and intuitively feedback the emulation results.
Combined with the actual situation of X80 pipeline steel production in hot rolling department of Tangshan Iron and Steel Co., Ltd., the experimental study on dephosphorization in duplex steelmaking process of the converter was carried out, and the influence of basicity of converter slag and oxidizing factors in slag on phosphorus removal was analyzed. The results show that: When the phosphorus content in hot metal is lower than 0.118%, the basicity of final slag in dephosphorization furnace and decarbonization furnace is controlled respectively at 1.6～2.0 and 3.3～4.1, the T.Fe content is controlled respectively at 10%～15% and 20%～35%, the average dephosphorization rate of dephosphorization furnace is38.35%, the maximum dephosphorization rate is up to 50.85%, the average dephosphorization rate of decarbonization furnace is 94.88%, the maximum dephosphorization rate is up to 95.69%, the terminal phosphorus content of converter molten steel can be controlled below 0.007%, and the minimum can reach 0.005%. The dephosphorization test results meet the production process requirements of X80 pipeline steel.
This paper introduces the design content of the conical column rotary cutting top combustion burner used in the blast furnace capacity replacement project of Shanxi Gaoyi Iron and Steel Co., Ltd.,and expounds the technical characteristics of this hot blast stove and its practical application effects on the 1680m~3 blast furnace. The process design of the hot blast stove in this capacity replacement project mainly applies the key patented technologies such as the conical column rotary cutting top combustion burner, the segmented structure of the hot air duct, and realizes the air supply temperature of 1230 ℃.The production practice after 1680m~3 blast furnace is put into operation shows that, adopting the hot blast stove technology of the conical column rotary cutting top combustion burner can effectively realize high air temperature, energy conservation, environmental protection and long life of the hot blast stove.
In the later period of the first generation service life of 3200m~3 blast furnace in a company,the production capacity of blast furnace is constrained and the various technical and economic indicators is poor due to the long-term adoption of furnace protection measures. Therefore, this company decided to overhaul and transformation the 3200m~3 blast furnace, it is hoped that through this overhaul and reconstruction, the main technical and economic index can reach the leading level of the blast furnace of the same class, and achieve the goal of high yield, high quality, low consumption, long service life and environmental protection of blast furnace under the premise of fully utilizing the old facilities and reducing the investment cost. This paper mainly introduces the main design overview of this 3200m~3 blast furnace overhaul and transformation, on this basis, analyzing and expounding the difficulties and progressiveness of engineering design, and summarizing the production indexes and application effect of advanced technique after putting into production of the blast furnace overhaul and transformation.
