In the paper, the purpose of reducing heat consumption is achieved on the premise of ensuring the stable coke quality by adjusting the lateral temperature as well as the temperatures of coke oven end and top space in the heating schedule of coke oven aiming at the problem of higher heat consumption of coking in the heating schedule of 7 m large capacity coke oven.

In this paper, the influencing factors of coking coal in hot performance test are analyzed and they are mainly reflected in the process of smelting coke with coking coal, sample preparation method of coke and the hot performance test process of coke. The effects of the process of smelting coke with coking coal on hot performance of coke are mainly reflected in type of test coke oven, temperature control program, coal capacity, density of coal charge and mode of quenching coke. Sample preparation is a key operation in the hot performance test for smelted coke and its influence on test values is significantly. With other conditions the same, the stability of test values for hot performance test of coke with pure handmade sample is the best, but the values are higher. The effects of test process on hot performance of coke are mainly reflected in the number of sample, flat-temperature zone of oven, thermocouple of temperature control, reactant gas and standard screen.

The main factors affecting quality of modified pitch are determined by analyzing the factors affecting qualification rate of modified pitch. They are low content of toluene insoluble in crude tar, flash oil flows backwards, poor cooling effect of flash oil and low degree of polycondensation of modified pitch in the reactor. The qualification rate of modified pitch is significantly improved by such measures as reducing rotate speed of centrifuges, transforming gas collecting tube of flash oil, absorption tube of flue gas and position of cooler of flash oil, increasing the softening point of mid-temperature pitch and temperature of reactor.

The blast temperature of hot blast stove of 3^# blast furnace of Baotou Steel is seriously insufficient, so the checker brick needs be replaced when cooling hot blast stove. The job is summarized in this paper. The preparatory work before cooling hot blast stove is sufficient, installation of equipment for cooling hot blast stove is smooth and process selection is correct, the whole cooling process lasts for 38 days. As a result, it is successful since the temperature of 1^# hot blast stove decreases from 800 ℃ to below 50 ℃, which provides references and theoretical basis for cooling hot blast stove of silica brick of Baotou Steel in the future.

In this paper, it is mainly elaborated the experimental study of W ore fines with the condition of sintering iron charge of Baotou Steel. The results showed that it was beneficial for increasing grade of sinter, reducing content of harmful ingredients, P and Al₂O₃, increasing sinter product ratio, reducing fuel consumption and increasing drum strength of sinter so that its reducibility is improved by replacing F ore fines with W ore fines. However, because the particle size of W ore fines is larger than that of F ore fines, the vertical sintering speed will increase and the sintering rate will decrease. The moisture of mixture needs to be reduced to stabilize the vertical sintering speed.

In the paper, the causes that load of 8^# and 9^# boilers of Power Supply General Plant of Baotou Steel decreases year by year with the co-combustion of coke oven gas are analyzed. It is judged to be the impurities in coke oven gas. Finally, the solutions are put forward by studying the influences of co-combustion of coke oven gas on boiler.

In the paper, it is introduced the ultra fast cooling control system suitable for hot-rolled dual phase steel is developed based on the CSP production line with short process and its industrial applications are realized. The results showed that the control of water supply pressure was realized with the pressure closed-loop of power pump and fuzzy PID control of relief valve; the control of flow for header was realized with the fuzzy control of control valve; the tracking of position of strip steel was realized with the accumulation of product of actual speed of strip steel and scan period of program. The cooling rate of hot-rolled strip steel with thickness of 6.0 mm was 190~210 ℃/s, the cooling rate of hot-rolled strip steel with thickness of 11.0 mm was 100~120 ℃/s, the medium temperature was controlled at (670±10)℃ and the coiling temperature was controlled at target value ± 30 ℃, which well met the product requirements.

In order to improve product quality, the steel-making process of 70 high carbon steel is optimized and improved by Baotou Steel. The results showed that the slab quality was significantly improved, levels of centre burst, center porosity and defect of non-metallic inclusions were all not over grade 0.5, proportion of columnar crystal was smaller and its texture was dense; the enrichment and segregation of carbon element in the center of casting blank of 70 steel were effectively reduced, central carbon segregation index decreased from 1.10 to 1.03 and no large-grained non-metallic inclusions were found in casting blank after the process optimization; the drawing fracture of wire rod was effectively suppressed and drawing property was significantly improved after the improvement.

In this paper, the cause for the crack at corner of casting blank is introduced. It is found out that the boron nitride precipitates along grain boundary and weakens the original austenite grain boundary as well as the crack is produced along grain boundary with the subsequent effects of straightening force by analyzing with such detecting techniques as metallographic examination and scanning electron microscopy.

The metallographic structure and mechanical properties of A333 Gr. 6 seamless steel tube at low temperature with such two heat treatment processes as "normalizing + tempering" and "normalizing" are studied and analyzed through comparative experiments. The experimental results showed that the A333 Gr. 6 seamless steel tube at low temperature with normalizing could meet the standard requirements so that the manufacturing costs were reduced and competitiveness of enterprise was enhanced.