球墨铸铁辊在轧机前后辊道中的应用

对QT600－3和45锻钢的性能及加工工艺进行比较,证明球墨铸铁在材料性能、加工工艺等方面都优于或接近于45锻钢。采用球墨铸铁来取代锻钢作为中板轧机前后辊道材质,可满足生产工艺要求,并可解决轧机前后因使用45锻钢辊而造成的钢材或铸坯的表面缺陷,大幅度降低生产成本。     

Unique properties of new steels microalloyed with vanadium and nitrogen

The influence of microalloying with nitrogen, vanadium, and other nitride-forming elements on the mechanical, technological, and functional properties of structural steel is investigated in laboratory and industrial conditions. Thanks to decrease in austenite grain size, dispersional hardening by nitride nanophase, and the formation of perfect fine substructure, a unique combination of properties is obtained: increase in strength (by 30–50%) and plasticity; resistance to fatigue, brittle, and corrosional failure; and seismic strength and fire resistance. Control principles for the properties of steels of different strength in rolling are developed. In this approach, quenching is unnecessary, and the resulting steel may be used in place of traditional nickel steel.     

Economical vacuum degassing of steel with the use of mechanical pumps

If greater use is to be made of vacuum technologies in out-of-furnace treatments of steel within Russia, more stringent requirements will have to be met in regard to the reliability, productivity, and efficiency of the pieces of equipment used to create the vacuum-the vacuum pumps. Unfortunately, Russian-made vacuum pumps do not presently meet these requirements. The equipment traditionally used to create a vacuum in units designed to treat steel outside the steelmaking furnace is based on steam-jet ejectors. This article compares the operating costs of a vacuum-degassing unit for 90-ton heats when the unit is equipped with mechanical pumps and when it has a steam-jet-ejector station. In the latter case, liquid-ejector pumps are used as the starting stage. It was found that the costs of the material resources and maintenance of the auxiliary equipment of a vacuum-degassing unit with mechanical pumps are roughly 10 times less than the analogous costs of a vacuum system with steam-jet ejectors. Another important advantage of vacuum-degassing units with mechanical pumps is that they are environmentally safe. __________ Translated from Metallurg, No. 4, pp. 58–61, April, 2007.     

Increasing the hardness of ShKh15 steel in its products

The methods of reaching a high hardness, which is the main characteristic determining the service resistance of rolling tools (sheet mill rolls, cogging-down rolls, the mandrels of cold-rolling tube mills, etc.), in low-alloy hypereutectoid steels are theoretically grounded. The “ultrahigh hardness” effect is shown to be achieved when the structure of a steel is preliminarily prepared and a disperse ferrite-cementite mixture forms in it. This structure is achieved upon special-purpose quenching followed by medium tempering. As a result of such a nonstandard heat treatment, carbide particles become an order of magnitude smaller than the secondary carbides that form upon conventional annealing. The steel grades to be subjected to the additional treatment are listed, and specific technological procedures that provide an increase in the hardness of quenched hypereutectoid steels are described. As a result, a hardness of 68–69 HRC is reached in experimental samples of commercial ShKh15 steel.     

A Sulfide Capacity Prediction Model of CaO-SiO2-MgO-FeO-MnO-Al2O3 Slags during the LF Refining Process Based on the Ion and Molecule Coexistence Theory

A sulfide capacity prediction model of CaO-SiO₂-MgO-FeO-MnO-Al₂O₃ ladle furnace (LF) refining slags has been developed based on the ion and molecule coexistence theory (IMCT). The predicted sulfide capacity of the LF refining slags has better accuracy than the measured sulfide capacity of the slags at the middle and final stages during the LF refining process. Increasing slag binary basicity, optical basicity, and the Mannesmann index can lead to an increase of the predicted sulfide capacity for the LF refining slags as well as to an increase of the sulfur distribution ratio between the slags and molten steel at the middle and final stages during the LF refining process. The calculated equilibrium mole numbers, mass action concentrations of structural units or ion couples, rather than mass percentages of components, are recommended to represent the slag composition for correlating with the sulfide capacity of the slags. The developed sulfide capacity IMCT model can calculate not only the total sulfide capacity of the slags but also the respective sulfide capacity of free CaO, MgO, FeO, and MnO in the slags. The comprehensive contribution of the combined ion couples (Ca²⁺ + O²⁻) and (Mn²⁺ + O²⁻) on the desulfurization reactions accounts for 96.23 pct; meanwhile, the average contribution of the ion couple (Fe²⁺ + O²⁻) and (Mg²⁺ + O²⁻) only has a negligible contribution as 3.13 pct and 0.25 pct during the LF refining process, respectively. The oxygen activity of bulk molten steel in LF is controlled by the [Al]–[O] equilibrium, and the oxygen activity of molten steel at the slag–metal interface is controlled by the (FeO)–[O] equilibrium. The ratio of the oxygen activity of molten steel at the slag–metal interface to the oxygen activity of bulk molten steel will decrease from 37 to 5 at the initial stage, and further decrease from 28 to 4 at the middle stage, but will maintain at a reliable constant as 5 to 14 at the final stage during the LF refining process. The proposed high-oxygen potential layer of molten steel beneath the slag–metal interface can be quantitatively verified.     

转炉冶炼65钢生产实践

介绍了安钢100t转炉生产65钢的工艺技术及冶炼效果,分析了转炉生产中、高碳钢的技术要点及影响因素。通过采取相应的技术措施确保了产品质量。     

Current trends in the production of railroad wheels and the effect of out-of-furnace treatment of the steel on their properties

Current trends in the production of railroad wheels show the use of some promising techniques: a reduction in the carbon content of the finished steel; degassing the steel in a vacuum to decrease its hydrogen content; more efficient deoxidation and alloying of the steel. When used together, these measures are ensuring that the finished steel has the mechanical and service properties prescribed for wheel steel. Studies and factory testing of a new technology for making wheel steel have shown that the oxygen content of the steel can be reduced by its self-deoxidation during vacuum degassing. This approach also helps lower the steel’s hydrogen content while saving deoxidizers. Researchers have discovered certain laws that govern the relationship between the characteristics of wheel steel and its contents of sulfur and gases. The amount of sulfur and gases in this type of steel can be reduced by using efficient parameters for the treatment that is administered outside the steelmaking furnace. __________ Translated from Metallurg, No. 8, pp. 56–60, August, 2006.     

Effect of heat treatment on the structure and properties of a high-nitrogen austenitic corrosion-resistant 03Kh20AG11N7M2 steel

The structure and mechanical and corrosion properties of a high-strength austenitic 03Kh20AG11N7M2 steel after quenching and aging at 500 and 800°C are analyzed. The phase composition of the steel and the mechanism of the decomposition of austenite during heat treatment are studied by electron-probe microanalysis and transmission electron microscopy. This steel is thermally stable upon heating to 800°C for 1 h and is stable to the γ → α and γ → ɛ martensitic transformation during deformation up to tensile strains leading to fracture. The homogeneous decomposition of a supersaturated γ solid solution at 500°C leads to the formation of disperse CrN nitrides, which increase the strength of the steel and insignificantly decrease its plasticity. In this case, the stress corrosion cracking resistance slightly decreases and the passivation of the steel increases in an corrosive medium without loading.     

The greening of materials science and engineering

The field of materials science and engineering is advancing at a revolutionary pace. It is now generally recognized as being among the key emerging technological fields propelling our world societies into the twenty-first century. The driving forces for this revolutionary pace are at once social, economic, political, and technological. For example, relatively recent changes in United States federal policies in environmental control, hazardous waste management, and energy conservation along with heightened international trade competition have resulted in major changes in material processing and use patterns. These changing patterns are creating new requirements for material developments, substitutions, and associated processes. This paper traces the emergence of materials policy and technological developments through four sub-periods of history: the birth and development of engineering in the United States (1825–1900), the evolution of a national research infrastructure (1900–1945), the evolution of a national science policy (1945–1973), and the intensification of global interdependency (1973-present). Future trends in materials developments and future policy requirements are outlined.     

冷轧超低碳搪瓷钢板的开发

简要介绍了冷轧超低碳搪瓷钢板的成分特点及工艺要求,分析了钢板的组织结构及析出相,研究了冷变形对氢在钢板中扩散系数和穿透时间的影响。实际批量生产结果表明,以及超低碳为基础、添加适量的合金元素,采用合适的工艺制度生产的冷钢板既具有优良的成形性能,又具有优良的抗鳞爆性能。     

热处理线淬火及回火炉改烧天然气工艺研究

文章通过对包钢无缝厂Φ180 mm机组热处理工艺改造进行研究,研究结果表明:通过热处理炉天然气改造,使加热炉加热钢管温度均匀、稳定,从而提高钢管一次性能合格率和一级品率;同时,在保证钢管性能满足技术要求的前提下,缩短生产时间,降低生产成本。     

Study of the Effect of Process Parameters in Steel Production on the Content of Corrosion-Active Nonmetallic Inclusions in Corrosion-Resistant Pipes

The main reason for the accelerated local corrosion of tubes is contamination of the steel by corrosion-active nonmetallic inclusions (CANI), which determine the metallurgical properties of tube steel in terms of their corrosion resistance. Studies have shown that there are two main types of corrosion-active nonmetallic inclusions: CANI₁ — inclusions based on calcium aluminates; CANI₂ — complex inclusions that contain calcium sulfide. In order to master to production of tubes of steel 20-PKS at the Volga Pipe Plant (VTZ), a study was made of the effect of the parameters of out-of-furnace treatments on the contamination of steel by CANI. 1. The mechanisms and main sources of formation of CANI in tube steels made by the VTZ were determined. The main reasons for the formation of CANI₁ in furnace slag containing thermodynamically active CaO are mixing of the metallic and slag phases during the argon blow and the simultaneous introduction of additions to correct the chemical composition of the steel. Inclusions of the CANI₂ type may be formed by deoxidation operations carried out with suboptimal proportions of added aluminum and calcium (lime). 2. The following measures are recommended to ensure that steel 20-PKS made by the VTZ is clean with respect to both types of CANI: • optimize the composition of the ladle slag (increase the average content of Al₂O₃, increase the average content of SiO₂ as much as possible, and in any case decrease the average concentration of CaO); • keep the mass ratio of added CaO to added Al within the range 1.5–2; • continue the argon blow done after addition of the last batch of ferroalloys for at least 15–20 min; • ensure that the intensity of the blow is at least 0.5–1.5 m³/min. 3. Vacuum-degassing steel in the ladle after treatment on a ladle-furnace unit makes it possible to distribute the CANI more uniformly over the volume of the steel. __________ Translated from Metallurg, No. 7, pp. 38–42, July, 2005.     

沙钢异地重建钢铁厂的自动化系统改造及新宽厚板轧机的供货

江苏沙钢集团购买了德国一家钢铁厂并将其在中国重建。奥钢联获得一系列设备改造合同,包括提供先进的工艺自动化系统和优化方案,以满足优质扁平材生产的要求。     

钢铁工业不同流程对耐火材料发展的影响

耐火材料的主要服务对象是钢铁工业，钢铁工业的工艺流程使用着不同的耐火材料，平炉的逐步被淘汰，模铸比的迅速减少，将使所用的耐火材料大幅度下降，甚至被淘汰，而冶金新技术，新流程的出现和发展，又推动了新型耐火材料的技术进步，本文叙述了钢铁工业不同流程对耐火材料发展的影响。     

钢铁工业不同流程对耐火材料发展的影响

耐火材料的主要服务对象是钢铁工业，钢铁工业不同的工艺流程使用着不同的耐火材料，平炉的逐步被淘汰，模铸比的迅速减少，将使所用的耐火材料产量大幅度下降，甚至被淘汰。而冶金新技术、新流程的出现和发展，又推动了新型耐火材料的技术进步。本文叙述了钢铁工业不同流程对耐火材料发展的影响。     

Vacuum degassing of chromium-nickel-molybdenum steel at the Magnitogorsk Metallurgical Combine

The Magnitogorsk Metallurgical Combine has conducted a study of the effect of technological factors on the hydrogen content of chromium-nickel-molybdenum steel after vacuum degassing. It was established that the most important factor is the hydrogen content of the steel before the degassing operation. The study also determined the effects of the circulation coefficient, the duration of the degassing operation, and the vacuum used in the treatment. __________ Translated from Metallurg, No. 7, pp. 68–69, July, 2006.     

Disk-type milling cutters with working elements made of powder high-speed steel. I. Technology for making semifinished products for the cutters

A technology is developed for making monometallic and bimetallic compacts for the production of disk-type milling cutters based on powder high-speed steel. The main operation in the technology is the hot upsetting of porous ring-shaped semifinished products, with the material flowing toward the center of the product. The article describes the methods used to fabricate the compacts from powder high-speed steel and protect against oxidation during heating, as well as the design of a disk-type milling cutter with a replaceable bimetallic ring. The requirements of the main manufacturing operations are presented. Novocherkassk State Technical University and the Novocherkassk Electric Locomotive Factory. Translated from Poroshkovaya Metallurgiya, Nos. 1–2(405), pp. 73–78, January–February, 1999.     

Effect of silicon on the wear resistance of high-carbon steels with the structures of isothermal decomposition of austenite during friction and abrasive action

The hardness and wear resistance during sliding and abrasive friction of 80S2 (0.83% C, 1.66% Si) and U8 (0.83% C) steels subjected to the isothermal γ → α decomposition in the temperature range 330–650°C and additional 5-min annealing at 650°C are compared. The optimum decomposition temperature is found to be 550°C. At this temperature, fine lamellar pearlite with the maximum hardness and wear resistance as compared to other pearlitic and bainitic structures forms in the silicon steel. The silicon-alloyed fine lamellar pearlite of 80S2 steel is found to have high hardness and abrasive wear resistance as compared to the similar structure in plain U8 steel; however, this pearlite has no advantages in the wear resistance under conditions of sliding friction on a steel plate. Silicon alloying of the bainitic structures in the eutectoid steel leads to a noticeable decrease in the wear resistance during sliding friction and abrasive action. Friction oxidation is shown to negatively affect the abrasive wear resistance of the silicon steel.     

不锈钢工程总体设计

介绍不锈钢工程的总体设计,总体设计提出优秀的工程方案并引领整个工程的实施,设计了世界上第一座不锈钢碳钢联合钢厂,并将炼钢与热轧紧密连接,在工程前期设计了不锈钢产品达到世界一流的详细标准,总体设计明确提出了确保世界先进水平的总工艺路线和主体生产单元的工艺方案,尤其独创了以高炉铁水为原料的不锈钢炼钢工艺,碳钢冶炼为脱磷脱碳双联法新工艺,不锈钢工程总体设计为不锈钢工程的成功建成投产奠定了基础.     

微碳汽车板03Al钢的冶炼技术

根据微碳汽车钢板的性能及成分要求，阐述了该钢板的生产工艺设计。论述了钢中主要成分碳、硫、氮、酸溶铝的控制措施及效果。展示了武钢第二炼钢厂在汽车钢板开发生产方面的广阔前景。