Strictly controlling the content of C, Mn, P, S and gas elements in steel is the key factor to improve the purity of molten steel, reduce the segregation of casting blank, and increase the resistance to H₂ S corrosion. The proper addition of alloys and the rational formulation of smelting, continuous casting and hot rolling process system is an important link to ensure that the product meets the standard requirements. The chemical composition and process design of X52MS hot rolled coils developed by Rare Earth Steel Plate Plant of Baotou Steel are reasonable, and the steel is pure, uniform in structure and has excellent comprehensive mechanical properties, in particular, it has resistance to hydrogen induced crack and stress corrosion resistance, product quality having reached the international advanced level.

Relying on 2 250 mm hot continuous rolling production line of Rare Earth Steel Plate Plant, adopting low－cost design of medium carbon and a small amount of Cu and Ti, through pretreatment of hot metal, converter smelting, LF refining, continuous casting, slab, heating, rough rolling, finish rolling, laminar cooling, coiling and other processes have successfully developed hot rolled steel strip for 520 MPa grade concrete mixing tank. The trial-produced results show that steel strip has good mechanical properties, stable and uniform steel strip performance, excellent formability, and good wear resistance. The steel strip contains less inclusions, and the steel is pure. The main components are ferrite and pearlite, and the grain size is small and uniform, and the grain size reaches 12 grades, the performance fully meeting the requirements for mixing tank use. It is successfully applied and sold in batches, praised by users, having broad application prospects.

In the paper, it is mainly discussed the use of special-shaped blank to produce Q345NQR2 corrosion resistant H beam. Through the chemical composition design and the process control of production processes in smelting, continuous casting, heating and rolling of Q345NQR2 corrosion resistant H beam. Both the microstructure, mechanical properties and corrosion resistance of Q345NQR2 corrosion resistant H beam are met the technical requirements for longitudinal beam corrosion resistance steel use as the railway vehicle underframe.

Through laboratory tests, the influence and analysis of Cr, Mo and V alloying on hardenability of bucket teeth steel are studied. The test results show that Cr, Mo and V alloying for improving the hardenability of steel, especially after J19 mm, the hardness of end hardenability obviously slows down.

Metallographic microscope and scanning electron microscope are used to analyze the SAPH440 stamping cracked steel plate. The analysis results show that the existence of segregated band of mixed crystal and pearlite in the steel plate and the combined action of precipitation of cementite at the grain boundary cause the crack of steel plate during stamping.

The effect of different coiling temperature on microstructure and mechanical properties of high strength engineering mechanical steel BT600MC is studied. In the smelting and rolling laboratory, three rolling billets with the same chemical composition are rolled by controlled rolling and cooling process, and the final coiling temperature is controlled at 500 ℃, 550 ℃, and 600 ℃ respectively, and after rolling, the steel plates are placed in the simulated coiling furnace for 2 h, and the temperature is cooled naturally. The experimental results show that when the coiling temperature is 600 ℃, the ferrite grain is more fine and uniform, and the comprehensive mechanical properties of experimental steels are better.

With the rapid development of motor industry in China, demand for cold rolled non-oriented electrical steel has increased year by year, according to the current situation, the test results of magnetic properties for cold rolled non-oriented electrical steel are analyzed, including sample preparation equipment, environmental temperature, sample size, sample weight, sample density and test equipment and so on. The results show that with the increase of shear times, mass and density, the iron loss increases, and the magnetic induction decreases; with the increase of ambient temperature, the iron loss and magnetic induction decrease. The analysis of factors affecting the test results of magnetic properties for cold rolled non-oriented electrical steel has great significance to improve the accuracy of test results.

In order to produce low chlorine root rare earth oxide, through the treatment of organic solvent entrainment in feed liquid and precipitant, the improvement of rare earth carbonate washing method and process method after rare earth carbonate, the content of chlorine root and other impurities in rare earth products can be effectively controlled, and the low chlorine root rare earth oxide products can be obtained.

In the paper, it is mainly described the structure and characteristics of the main drive electric control system of roughing mill in large H-beam production line for Rail and Beam Plant of Baotou Steel. The system adopts SIMADYN D full digital vector control system of Siemens to control; through Profibus_DP network to achieve signal acquisition and data exchange with one level automation system, the system can adapt to the demand of rolling conditions being frequent reversible, heavy impact load and high overload capacity.

In the paper, it is introduced the transformation of control system for walking beam furnace in Seamless Plant. The old Siemens S5 system has outdated equipment, high failure rate, complicated communication, poor programmed readability and is difficult to maintain. After the transformation, Siemens S7-300 controller is used, which has good versatility and high control precision. The programming adopts STEP7 + WINCC mode, and the program adopts modular programming mode with clear structure, strong expansibility and is easy to maintain.