The strength of 440 MPa grade phosphorous high-strength IF steel independently developed by Baotou Steel is improved by adding such alloying elements as Si, Mn and P based on ultra low carbon steel. The control requirements of its composition and production process are strict as well as production is very difficult. In the paper, the influences of chemical elements on stamping performance of 440 MPa grade high-strength IF steel are mainly studied. The microstructure of steel strip, inclusion morphology and precipitation behavior of the second phase particles are analyzed with metalloscope and scanning electron microscope. The mechanisms of action of hot rolling processes such as finishing and coiling temperatures, continuous annealing process of cold rolling on microstructure and mechanical properties are explained. The mechanical performances of tested steel strip are stable and could meet the relative technical requirements through formulating reasonable process route and strict control.

In the blast furnace bag dust recovered from flue gas in ironmaking process, there are not only the iron, carbon and oxygen contained in solid charge, but also such valuable elements as zinc and lead in the form of oxide as well as potassium and sodium in the form of chloride. In view of the influences and economic value of these elements on ironmaking production, the experiment of “leaching of NH₄Cl → replacement and impurity removal → electrolysis” for blast furnace bag dust is designed and carried out. As a result, the products of potassium ammonium chloride and zinc in line with national standard as well as the optimum conditions of leaching zinc and lead from blast furnace bag dust, precipitation of zinc in leachate, replacement and electrolysis are obtained.

In this paper, the improvement is from the point of view of deformation process by increasing the number of roll in finished pass to form four-roll finished pass, increasing the constraint in direction of depth of rail and limiting free spread of rail surface so as to improve dimensional accuracy of depth of rail aiming at the existing problems in universal rolling of rail. The numerical calculation is performed using ANSYS/LS-dyna, deformation states in different conditions are analyzed, defects are amended so that the optimal solution is obtained. The better effects are obtained by applying it in production line of rail, fluctuation range of depth within the full length range of rail is reduced and defect of “high zone” caused by local depth fluctuation is solved so that the safety of running for high-speed train is improved.

The Yangliugebu Iron Ore occurs in the amphibolite gneiss of Eastern pentamolecular formation of Seltengshan (rock) group in Neoarchean and the ore body is composed of magnetite quartzite. The amphibolite gneiss and magnetic anomaly are direct indicators for deposit. The iron ore in this area is with stronger magnetic properties, so it can be as an indirect indicator for deposit.

In the paper, the particle size distribution of blended coal is optimized according to the quality indexes of blended coal with different granularity compositions through analyzing properties of blended coal for tamping coking of Baotou Steel with different particle sizes so that standard deviation of granularity composition for blended coal gradually reduces. In addition, the selective comminution of hard coal is carried out through selective precomminution technology so that the quality of blended coal is stabilized. On the premise of ensuring stability of coal cake, 1/3 proportion of coking coal and gas coal is improved so that the consumption of high-quality coking coal and cost of blending coal reduce.

In the production process of 2 250 mm hot continuous rolling band steel, there would be a large number of warp defects at edge of low carbon steel. In order to reduce or avoid the occurrence of warp defect, its causes are analyzed from its morphology, the relation between generation of warp and edging draught of vertical roll of roughing mill, time in furnace and tapping temperature of slab as well as control of Mn/S for composition of slab. Finally, the corresponding countermeasures are formulated so that the occurrence rate of warp defect is reduced.

As one of the important hot tools in perforated rolling process of seamless steel tube, the quality of guide plate directly affects quality and cost of steel tube. In this paper, the effects of modification of rare earth and heat treatment on carbide shape in high chromium nickel alloy guide plate are studied aiming at the problem of its fragmentation during use. Moreover, the microstructure of net carbide in high chromium nickel guide plate is fragmentated and broken, matrix structure is refined and carbide uniformly distributes by selecting reasonable process so that the purpose of improving service life of guide plate is achieved.

In order to improve the grade of iron concentrate and reduce the contents of other gangue minerals in iron concentrate, the concentration with wash mill is added after finely sieving in Concentration Plant of Baotou Steel. Moreover, such tests as feeding concentration of wash mill, magnetic field intensity, opening of water valve and bottom valve are carried out. Finally, the grade of iron concentrate increases from 56.8% to 67.0%, recovery rate of iron is 93.42% so that the effects of quality improvement and impurity reduction are achieved.

The influences of cold rolling reduction ratio and annealing time on the stamping performance of Ti-IF deep drawing steel are studied by means of such equipment as optical microscope, X-ray diffractometer and tensile tester aiming at the phenomenon that the stamping performance of cold rolled cover annealing thick deep drawing steel is unstable. The results showed that the r value and tensile strength tended to increase and change of n value was not obvious with the increase of cold rolled reduction ratio; r value increased, tensile strength decreased and change of n value was not obvious with the extension of annealing time. The process is optimized according to the test results so that density of {111} texture is enhanced and stamping performance of product is obviously improved.

Three-dimensional mathematical model is established with commercial software aiming at the tundish of slab caster to calculate flow field in tundish with different flow control device conditions of tundish as well as analyze the effects of different schemes on flow condition of molten steel and average retention time and the situations of inclusions in steel with adopting the optimization scheme. The results showed that the volume of dead zone for tundish reduced by 10.61% and the time that tracer appeared in tundish extended by 4.31% comparing the optimization scheme with original scheme, which are all beneficial to mixing molten steel in tundish as well as floating and removal of inclusions. Moreover, the level of inclusions in steel adopting optimization scheme could satisfy the requirements of production technology.