The exploration for effects of rare earth (RE) on phase transformation of Fe-based alloy is significant in the development process of advanced high strength steel containing RE. In the paper, the effects of La and Ce on martensite phase transformation of steel are studied from such two aspects as driving force and minimum energy path (MEP) using first principles calculations. The calculations of formation energy revealed that the stability of fcc-Fe was increased and stability of bcc-Fe was decreased through substitution of RE for part of Fe atom so that the driving force of martensite phase transformation was decreased. Meanwhile, the analysis on generalized solid-state nudged elastic band method indicated that there would be an additional energy barrier when phase transformation went on to the FM state with ratio c/a of 1.14 along Bain transformation path in the system containing RE, which was related to the sudden decrease of magnetic moment caused by the hybridization between atomic orbital of RE and nearby atomic orbital of Fe.

In this paper, the effects of lanthanum content on inclusions in steel are studied by the induction furnace experiment and thermodynamic calculations. It was concluded that the rare earth oxysulfide was formed firstly, then aluminate, oxide, carbide and sulfide of rare earth lanthanum were formed as well as lanthanum-silicon and lanthanum-aluminum intermetallic compounds and rare earth hydride with smaller reaction trend were formed finally under the thermodynamic condition of molten steel of Q450NQR1 steel for railway carriage. It is obtained that the inclusions of LaAs and LaP could be generated during solidification process through the calculations with Ohnaka segregation model.

The automobile beam steel is mainly used for such structural components as longitudinal beam, lining beam and cross beam on the chassis of heavy truck, so its comprehensive performances are vital to the driving safety and service life of the whole vehicle. The TiN inclusions with large size seriously harm the processability and usability of BT700L steel, while the amount and morphology of inclusions in steel as well as low-temperature impact and corrosion resistance of steel could be improved by rare earth. In the paper, the effects of rare earth Ce on formation of TiN inclusions in BT700L steel are studied based on the industrial tests and thermodynamic calculations. The study results showed that pure TiN inclusions and composite inclusions of Al-O+TiN were mainly formed in the BT700L steel without Ce, while pure TiN inclusions and composite inclusions of Ce-Al-O(-S-Ca)+TiN were mainly formed in the BT700L steel with Ce. The results of thermodynamic calculations showed that precipitation temperature of TiN inclusions could be decreased with the increase of Ce content in BT700L steel so that the precipitation of TiN inclusions was restrained. Such methods as reducing contents of nitrogen and titanium in steel as well as increasing solidification rate could be taken to decrease the sizes of TiN inclusions.

In this paper, the effects of rare earth element Ce on DWTT properties of pipeline steel are studied in laboratory by taking X80 pipeline steel as the research object. The study results showed that the addition of rare earth element Ce could help to improve the low temperature toughness of test steel. The impact energy of sample after adding rare earth element Ce could reach 210 J at -40 ℃, which is increased by 19.3% compared with that of sample without adding rare earth. The addition of rare earth element Ce could help to reduce the ductile-brittle transition temperature of pipeline steel. The impact energy of heat affected zone after welding for sample without adding rare earth element is 189 J and the impact energy of heat affected zone for sample after adding rare earth element Ce could reach 216 J, which is increased by 14.3%.

The applications of rare earth elements in steel materials play an important role in optimizing their performances. In the paper, it is introduced a type of reinforced wear resistant steel with rare earth TiC particle is prepared by taking rare earth element Ce as main additive as well as systematically discussed the effects of finish cooling temperature on its microstructure and wear resistance. The microstructure analysis indicated that the Ce element could effectively refine the TiC particle with long strip and chain shape in as-cast structure during solidification process as well as the content of retained austenite could be reduced with finish cooling temperature decreased during rolling process. The abrasion test showed that the microalloying TiC particle with rare earth element Ce could effectively prevent abrasion so that the wear resistance of plate could be improved.

The effect laws of coiling temperature on microstructure and texture of 50W470 non-oriented silicon steel under hot rolling and normalizing processes are studied with such detection and analysis technologies as the optical microscope (OM) and electron back-scattered diffraction (EBSD). The results showed that high temperature coiling could promote the transformation of deformed microstructure in central layer of hot rolled plate to equiaxed grain without distortion. The promoting effect of coiling at 740 ℃ is better than that of coiling at 600 ℃. After high temperature coiling, the proportion of favorable texture {100}+{110} is increased, while the proportion of unfavorable texture{111} is decreased. After normalizing, the microstructure of high temperature coiling plate is with perfect recrystallization and the deformed microstructure is disappeared as well as the coiling plate with temperature of 740 ℃ is with more favorable texture {100}+{110} and fewer unfavorable texture{111} than those of coiling plate with temperature of 600 ℃.

In this paper, the fluctuation of impact energy for Q690 steel plate with large thickness of 80 mm are analyzed. The low temperature impact tests of samples taken from different positions of plate thickness are carried out as well as their fracture and microstructure are compared and analyzed with scanning electron microscopy and metallographic microscope. The differences of impact energy at different positions of plate thickness are great, which are 14.9 J in the center, 27.2 J at the quarter part and 95.4 J near the surface. The corresponding microstructures are coarse tempered bainite and a small amount of tempered sorbite structure with orientation of martensite in the center, tempered sorbite and bainite structures with orientation of martensite at the quarter part as well as fine tempered sorbite structure with orientation of martensite near the surface. The analysis results showed that the main cause for fluctuation of impact energy was the differences of microstructure and grain size. The experiment showed that the higher the proportion of bainite in microstructure, the larger the grain size and the lower the corresponding impact energy. Based on the CCT(continuous cooling transformation) curves of Q690 steel, it is analyzed and judged that insufficient cooling during quenching process causes insufficient cooling speed from the quarter part to the center of steel plate due to the larger thickness specification of Q690 steel plate so that the whole martensitic structure could not be obtained after quenching, microstructure in the direction of plate thickness is uneven, especially different proportions of bainite structure appear at the quarter part and in the center of plate thickness, which cause the fluctuation of impact energy. The uniformity of microstructure for Q690 steel plate with large thickness specification is improved so that the impact energy and its stability are improved by optimizing on-site quenching and tempering process.

The deformation characteristics in rolling process are analyzed through calculating the changes of temperature, strain and external dimensions during the deformation process of H beam with bilinear hardened material model by taking HW300×300 as the typical case. The calculations are with the thinking of all process and calculation method of thermodynamic couple, process temperature is used as deformation temperature of rolled piece as well as the effects of uneven temperature of cross section are taken into full consideration so that the calculation results are more close to actual situations, which provide the reliable basis for process optimization. The calculation results showed that there was necking near the trigonum on waist of H beam due to inhomogeneous deformation, local deformation at flange end would cause precision of flange width to change as well as rolling deformation work would transform into heat energy so that internal temperature of rolled pieces would rise.

The scientific research innovation management system of Baotou Steel, taking the Management Methods for Scientific Research Projects of Baotou Steel as business framework, covers such five modules as declaration management of scientific research projects, contract management, acceptance management, result management and expense management. As a result, the on line management of the whole process from project approval, accreditation, acceptance and concluding project to results declaration after completing project for scientific research projects of Baotou Steel is realized as well as expense budgets and actual performances of scientific research projects could be controlled according to organization, project and time.

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.