As an efficient energy conversion system, the combined cycle power plant (CCPP) is widely used in such industrial fields as iron and steel. As the core component of CCPP, stable operation of waste heat boiler directly affects efficiency and safety of the entire unit. In the paper, the in-depth study aiming at frequent leak problem at the upper part of high pressure evaporator of supporting waste heat boiler facing flue gas in gas turbine unit of a steel plant is carried out as well as the leakage causes are analyzed to be that the deposit sediment in its lower header causes water flow rate in evaporator tube to be decreased so that impingement corrosion of steam water mixture is generated. Meanwhile, the phenomenon of “flue gas corridor” in local area of furnace exacerbates the corrosion process. For these problems, such measures as replacing leaking pipe section, reforming periodic discharge pipe system of lower header to improve efficiency of pollution discharge, repairing and perfecting gas baffle to reduce formation of “flue gas corridor”, optimizing periodic pollution discharge operations as well as formulating periodic plans of inspection and maintenance are taken to effectively solve the leak problem for high pressure evaporator so that the stability and safety of equipment are improved.

The transformations of scientific and technical achievements for colleges and universities play an important role in supporting and promoting the national economic construction and social development as well as the transformations of scientific and technical achievements for colleges and universities in western ethnic minority region are with its own development characteristics. In the paper, the transformations of scientific and technical achievements for metallurgy universities in western ethnic minority region are analyzed from multiple perspectives such as the quantity, amount of money, subject distribution and cycle of achievement transformation based on the data of achievement transformation for a university in western ethnic minority region in 2020-2022, which could provide references for transformations and applications of scientific and technical achievements in western ethnic minority region.

The effects of riser brick for casting ingot mould used in the smelting equipment of laboratory, vacuum induction furnace on quality of steel ingot are greater. The molten steel in vacuum melting furnace is poured into ingot mould through riser brick and steel ingot is formed after cooling. The flow velocity and angle of the molten steel flowing through riser brick, inclusions in molten steel and inner wall of ingot mould all affect quality of steel ingot. In the paper, the optimization design for structure of riser brick is introduced, which is to add a diversion platform. On the one hand, the scouring force of molten steel to inner wall of ingot mould is reduced so that the service life of ingot mould and surface quality of steel ingot are improved; on the other hand, the retention time of molten steel in riser brick is increased so that the inclusions in molten steel float to be removed and internal quality of steel ingot is improved. The practices prove that the design of riser brick with optimization and transformation is reasonable as well as application effects are good.

The 5×××series aluminum alloy belongs to Al-Mg alloy system and Mg is its main element, which is a type of wrought aluminum alloy. The 5××× series aluminum alloy is with better corrosion resistance and is often as rust-proof aluminum alloy, which is widely used in the field of off-shore building. It is also with such advantages as light weight and high strength as well as is also widely used in the fields of automobile parts manufacturing and ship structure making. In this paper,the research progress for the effects of alloying elements and heat treatment process on comprehensive properties of 5××× series aluminum alloy in recent years is summarized as well as the effects of rare earth elements on microstructure and properties of 5××× series aluminum alloy are mainly analyzed, which provide the theoretical guidance for subsequent research and development of 5××× series aluminum alloy with higher comprehensive mechanical properties.

In this paper, the continuous casting billet of low temperature Hi-B steel, metallographic structure and texture of plates after such processes as hot rolling, normalizing, cold rolling, decarburizing annealing and high temperature annealing are observed with metallographic microscope and X-ray diffractometer (XRD) as well as the evolution laws of microstructure and texture in the whole process are analyzed. The results showed that the macrostructure of continuous casting billet was mainly columnar crystal and proportion of equiaxed crystal zone was 7%~12%; microstructure of hot rolled plate was composed of alternant banded structure of ferrite and pearlite; microstructure of normalized pickled plate was composed of fine crystal zone and recrystal microstructure. The textures at 1/8 of thickness of hot rolled plate and normalized plate are mainly Goss texture and brass texture as well as strong Goss texture is formed with the secondary recrystallization after high temperature annealing.

The continuous cooling transformation laws of X120M pipeline steel is studied with Gleeble 1 500 thermal simulated test machine as well as it is with controlled rolling and controlled cooling in laboratory. The results indicated that the microstructure of test steel was mainly lower bainite and martensite when cooling rate was at 20~50 ℃/s. When the finish cooling temperature of test steel is at 380 ℃, its yield strength is 900 MPa, tensile strength is 1 015 MPa, elongation is 18%, impact energy at -30 ℃ is 180 J and shearing area of drop weight tear test at -20 ℃ is 100%. The mechanical properties could meet the standard requirements.

In the paper, the fit tolerance and chamfer structure for quick-change coupler of oxygen lance as well as flexible connection mode between coupler and nozzle of medium are analyzed in detail. The fit dimension, chamfer length, surface roughness of fitting surface and type of connection of compensator are improved based on the analysis results combining with actual situations on site. On the premise of not affecting original using functions of oxygen lance, the rapid replacement for oxygen lance of 240 t converter is realized so that the duration of replacing oxygen lance is shortened, labor intensity of workers is reduced and safety of operating personnel is ensured.

The effects of microstructure of high-strength anti-seismic fire-resistant H beam for building structure on its strength, toughness and high temperature strength are studied with such analysis means as TEM (transmission electron microscope), metallographic microscope and EBSD (electron back-scattered diffraction). The results showed that the controlled rolling and controlled cooling were not needed under the premise of reasonable chemical composition design, two-phase structure of air cooling bainite and ferrite for test steel after hot rolling was obtained. It is found by observing the microstructure after holding at 600 ℃ for 3 hours that there is nano-level interphase precipitates in ferrite and their line spacing is about 24~34 nm. For the hot rolled high-strength anti-seismic fire-resistant H beam for building structure, its yield strength≥500 MPa, elongation≥22%, yield ratio≤0.85, impact energy at -20 ℃≥34 J and yield strength after holding at 600 ℃ for 3 hours≥310 MPa.

A large amount of particulate matter, sulfur dioxide and nitrogen oxide are generated in production process of iron and steel enterprises. In order to reduce further damage of these pollutants to the atmospheric environment, it is necessary to carry out desulfurization and denitrification treatments for discharged flue gas. The conventional technologies of desulfurization and denitrification are with such drawbacks as large occupied area and smaller adaptative reaction temperature interval. In the paper, a new integrated technology of desulfurization and denitrification with fixed bed is emphatically introduced, which is with such characteristics as small occupied area as well as better adjustability of desulfurization and denitrification efficiency so that it is suitable for different production environments. After the technology is applied, the integration of dust removal, desulfurization and denitrification could be achieved as well as concentrations of pollutants could all reach the ultra-low emission standard.

The old horse of 7^# blast furnace of Baotou Steel is deeper. In order to shorten the project duration and reduce workload of removing residual slag iron in furnace hearth after blowing out, the mode of dropping stockline and discharging residual liquid iron is adopted. It is one of the most important links in blowing out operation of blast furnace to discharge residual liquid iron and its effect directly affects the clearance time of furnace hearth. In the paper, the process of discharging residual liquid iron for 7^# blast furnace of Baotou Steel during blowing out is mainly introduced. The previous preparation work mainly includes such as activating furnace hearth, confirming position of residual liquid iron notch, calculating amount of residual liquid iron and making residual liquid iron runner. The cutting of shell of blast furnace and cooling stave, manufacture of mud sleeve for residual liquid iron notch as well as the whole process of discharging residual liquid iron after blowing out are introduced in detail. The process of discharging residual liquid iron of 7^# blast furnace is safe and ordered. After blowing out, it is found that there is basically no residual iron in the furnace hearth when cleaning it, which indicates that the effect of discharging residual liquid iron this time is good and experiences are gathered for discharging residual liquid iron in future heavy and medium repairs of blast furnace.