In this paper, the production practices on improving automatic casting ratio of ladle are introduced as well as various improvement measures are proposed through deeply analyzing the factors influencing automatic casting of ladle combining with production practices. The practices showed that the automatic casting ratio of ladle could be increased to over 99.5% so that the goal of reducing unplanned products produced by cast billets with burning oxygen is achieved through improving the quality of stuffing sand, optimizing sand filling device, formulating plan of replacing nozzle, strictly controlling time of steel filling according to steel grade, preventing back flow of steel slag and shortening standing time of liquid steel.

In the paper, the detection method of magnesium content in silica-based composite material is studied and its purpose is to accurately detect magnesium content in the process of preparing silica-based composite materials so as to control the content of magnesium silicate in final product. During the experiment, the method for determining magnesium content in magnesium silicate-carbon-encapsulated silicon oxide composite material with the inductively coupled plasma atomic emission spectrometry (ICP-AES) is established. Finally, it is verified that the detection limit is 0.004 mg/L, relative standard deviation of detection results is less than 5% and linearly dependent coefficient is above 0.999 so that this method is satisfied with the test of magnesium content.

The transformation structure and critical points of phase transformation for rare earth alloyed high carbon wear resistant steel as well as continuous cooling transformation (CCT) curve of undercooled austenite at different cooling rates are studied by metalloscope, field emission scanning electron microscopy and quenching dilatometer. The results showed that the critical points of phase transformation were Ac₁=742.6 ℃, Ac₃=816.5 ℃ and Ms=307.0 ℃. When cooling rate is less than 0.4 ℃/s, the microstructure is a small amount of ferrite+pearlite; when cooling rate is 0.4 ℃/s, the microstructure is single-phase pseudo eutectoid pearlite; when cooling rate is greater than 0.5 ℃/s, the microstructure is gradually transformed to martensite; when cooling rate is greater than 4 ℃/s, there is only the microstructure of martensite+retained austenite in the steel.

The feedback of user is that the elongation of cold rolled sheet with cold rolled base material SPCC manufactured by 2 250 mm production line after cold rolling and annealing is low, part of flow forming is not easily to form in punch forming process and cracking rate is higher. The cause analysis showed that its high Mn content was one of the causes for slightly higher strength of steel strip so that elongation was low and steel strip was easy to crack; cooling modes of the two production lines were different, the cooling mode of preconcentration was adopted by 2 250 mm production line and the cooling mode of predispersion was adopted by CSP production line so that the strength of hot rolled steel strip manufactured by 2 250 mm production line was slightly higher, elongation was low and steel strip was easy to crack. The elongation of hot rolled steel strip manufactured with raw materials with thickness of 3.0~5.0 mm by 2 250 mm production line is lower than that of hot rolled steel strip manufactured by CSP production line so that the elongation of cold rolled steel strip after cold rolling and annealing is also slightly higher due to the “heredity” of rolling.

The coupling is an important part of oil casing and oil tube as well as they are connected into tubing string by coupling with the mode of screw joint. In order to improve the anti-galling property of thread of coupling, the high temperature manganese phosphating is usually adopted for coupling so that it is corrosion resistant, the friction is reduced and lubrication performance is improved. In this paper, the effects of free acidity, total acidity and acid ratio on the quality of phosphating film and phosphating reaction time are studied by experiments. The phosphating process parameters are further optimized to control the phosphating film weight to be within certain range so that more compact and homogeneous phosphating film is obtained.

As the calibration item of Rockwell hardness tester, hardness of ball indenter for Rockwell hardness tester needs to be calibrated by Vickers hardness tester. Due to ball indenter is smaller, it cannot be fixed on smooth test bed so that calibration cannot be carried out. Moreover, it is needed to refer to correction coefficient table after calibration, the corresponding results can only be obtained through interpolation method so that work efficiency is reduced. In terms of hardware, the mold for fixing ball indenter of Rockwell hardness tester is made by precise machining and selecting suitable materials to ensure the stability of ball indenter. In terms of software, the linear regression is performed based on the data in correction coefficient table to obtain fitted equation of correction values. Moreover, the correction table for hardness of convex sphere is edited with the formulas in the WPS table so that operation process of data processing is simplified. As a result, the calibration of hardness for ball indenter could be carried out so that the work efficiency and test accuracy could be improved.

The drop weight tear test (DWTT) is used to test the toughness of materials, mainly for studying the low-temperature toughness of metal materials. In the paper, the microstructure and morphology of samples corresponding to different area proportions of brittle fracture are compared and analyzed with optical microscope aiming at the unqualified DWTT properties of products during trial production process of heavy gauge X80M hot rolled steel strip. The composition segregation in thickness direction of casting blank is tested. It is found that the severe segregation in thickness direction of steel strip is the main factor influencing the DWTT properties by analysis. The center segregation of casting blank and DWTT properties of product are improved effectively by adjusting the arc alignment precision of segment and optimizing the specific water amount of continuous casting machine so that the goal of stable production of hot rolled steel strip for heavy gauge X80M pipeline steel is realized.

In the paper, the general situations of production processes for 380HBW grade LH on line heat treated rail exported to Mexico are introduced. Its batch production is successful by microalloying component design, control of high cleanliness for smelting process as well as accurately regulating and controlling the on line heat treatment process of rail. All its performances could satisfy the technical requirements of users and requirements of AREMA standard as well as pass the SGS international testing and certification so that it could satisfy the operating requirements of freight train with great axle load on heavy haul railway abroad. It has been exported to such countries as Mexico, Australia and America.

The characteristics and change rules of wear behavior for rail with different load conditions are analyzed through experimental study on wear of on line heat treated U20MnH rail combining with the morphology features of wear surface and profile for samples observed by microscope and scanning electron microscope. The results showed that the wear loss of on line heat treated U20MnH rail was significantly reduced with increase of load under load conditions of 1 200 N, 1 500 N and 1 800 N respectively.

The identification resolution system for industrial Internet of Baotou Steel is connected to the national top-level node upward as well as radiates constituent companies in the whole industry chain and various application systems downward to form such typical application modes as enterprise management, manufacturing, product tracing, supply chain management and life cycle management so that the effects of reducing costs, improving quality and increasing efficiency are gradually emerged. Meanwhile, it will help enterprises get through data sharing channel, realize full control of different objects and full service of different products, effectively promote prosperity and development of identification system + integrated innovative application, further promote deep integration and high-quality development of industrial Internet and real economy as well as help enterprises accelerate digital transformation and upgrading through the application researches of identification resolution system for industrial Internet in the iron and steel industry.