In the paper, it is introduced the more elaborate distinction and logic control of different materials, categories, widths, thicknesses, coiling diameters and surface treatment methods with automatic control system through the accurate calculation of model aiming at the “heart-shaped” collapse of coil with thinner strip steel as well as the causes of collapse core for steel coil are analyzed through the change of interlaminar stress for steel coil. Moreover, the cone gradient of coiling tension is realized step by step with the change of coiling diameter as well as the realization and application of tension control scheme of hard core for preventing collapse core are discussed comprehensively.

In order to improve the problem of transverse corner crack for peritectic steel, hypo-peritectic steel, medium carbon steel and microalloyed steel containing B, Nb, V and Ti, the chamfering crystallizer successively comes into service of 1^# and 2^# conticasters. As a result, the defect of transverse corner crack is improved obviously, but due to the changes of cooling mode at corner, such defects of billet as longitudinal corner crack, scab and indentation appear easily as well as they could even cause the accident of longitudinal crack and bleed-out. In the paper, it is mainly analyzed such common defects of chamfering ingot blank as longitudinal crack, scab and indentation so that the slab defects are effectively controlled through such measures as adjusting the taper coefficient of copper plate with narrow edge and cooling intensity of secondary cooling water as well as optimizing the assembly accuracy of equipment and modification of key equipment.

In this paper, such aspects as the design background, design process and practical applications of new-type slab turnover machine are introduced. The new-type slab turnover machine in production line of wide and thick plate is designed based on analyzing the defects of traditional slab turnover machine as well as the process requirements and working condition of newly designed slab turnover machine needed to satisfy. It is with such characteristics as high load capacity, stable and reliable performances as well as large range of cover length of turnover slab so that it is suitable for various load lifting devices of slab and with low construction cost.

There are more factors influencing the performances of ultra low carbon stamping products. In this paper, the influence rule of such parameters as contents of different strengthening elements and annealing temperature as well as levelling process on the performances of stamping products is explored. The results showed that the yield strength of product tended to increase with the increase of contents of carbon, manganese and phosphorus as well as the influence degrees of carbon content on the products with different thicknesses were different; with the increase of annealing temperature, the products mainly underwent such three stages as reverting, recrystallization nucleation and grain growth; tensile strength decreased with the running speed of steel strip in annealing decreased.

In this paper, it is elaborated the performance characteristics and strengthening mechanism of cold rolled continuous annealed low alloy high strength steel HC500LA for automobile structure as well as the whole production process plan including chemical composition, hot rolling, cold rolling and continuous annealing processes. The production practices and batch trial of automobile manufacturer showed that the HC500LA products of Baotou Steel was with good comprehensive mechanical properties as well as stable and mature production process so that it was with batch supply capacity.

The application of eccentricity control for high precision gauge control of tandem cold mill is analyzed through comparing the conventional and extended modes in automatic gauge control (AGC) system of tandem cold mill. Moreover, such influencing factors of thinning for product thickness as eccentricity control of rolling mill, thickness variation of incoming materials, variation of tension control for rolling mill as well as precision of thickness gauge and tachymeter are analyzed by comparing the production situations of rolling mill with different thickness control modes. As a result, the improvement scheme that rolling gauge of rolling mill compensates control model is proposed to improve the thickness precision of products.

The continuous annealing process of phosphorus high strength IF steel 210P1 is tested. The effects of different continuous annealing temperatures on the microstructure and mechanical properties of cold rolled strip 210P1 are investigated with such analysis methods as optical microscope, scanning electron microscope and universal tensile testing machine. The results showed that the grain size gradually increased, non-recrystallization microstructure transformed to recrystallized microstructure and form of microstructure changed from long strip to equiaxed shape with the increase of annealing temperature. The annealing microstructure of steel 210P1 was all ferrite and there was a small quantity of precipitated phase of TiN at grain boundary. The detrimental phase of FeTiP was not discovered so as to demonstrate the continuous annealing process could not cause the phase of FeTiP to be precipitated. The yield strength and tensile strength tended to decrease, elongation, n value and r value tended to increase as well as r value of steel 210P1 increased obviously especially after the annealing of 780 ℃ with the increase of annealing temperature.

In the paper, it is expatiated the characteristics and mechanism of cold rolled phosphorous high-strength steel, analyzed various production difficulties of such processes as cold rolling and pickling combining with the chemical compositions and physical properties as well as summarized the countermeasures for such various processes as welding machine, pickling and rolling mill of producing phosphorous high-strength steel through a large number of production practices and optimization of process parameters so that the production line could be with continuous and stable production.

The galvanized dual phase steel is the high strength steel widely applied in the field of automobile sheet. In order to meet the requirements of lightweight raw material for automobile manufacturer, the galvanized dual phase steel HC300/500DPD+Z is successfully developed through adopting the microalloying composition system of C-Si-Mn-Cr as well as such reasonable process design as hot rolling, pickling, annealing, hot galvanizing and finishing based on the characteristics of 2 030 mm hot galvanizing production line. The production process and using effects of users showed that its mechanical properties were qualified, production process was mature and it was with good formability to meet users’ requirements when applied for automotive structural parts.

In the paper, it is mainly introduced how the heating zone, soaking zone, slow cooling section, fast cooling section, over aging section and exit section combine such equipment as gas-fired radiant tube, electric radiant tube, draught fan, thermocouple and infrared thermometer to conduct the temperature control of radiant tube and strip steel so that the heating or cooling temperature of strip steel in annealing furnace desired by process could be reached through this two temperature control modes.