Latest ArticlesThe influence factors of KR process, as well as desiliconization and dephosphorization pretreatment were studied by using 150 t ladle furnace. In this study, the reuse resources such as converter dust and iron oxide ball were used as the oxidant, and the desulfurizer was added into the ladle furnace at a certain ratio in the condition of KR hot metal pretreatment, the technological effect for simultaneous removal of silicon and phosphorus was sought factor. The result shows that remove part of silicon and phosphorus in molten iron is feasible, but the condition is harsh, the current production conditions can not be fully met.
In this paper, the chemical compositions, processing parameters and testing results of Q890D high strength steel were introduced. Through the design of reasonable chemical composition system, control of rolling and cooling process, and off-line quenching and tampering treatment, the high strength plate thickness is up to 25 mm with a yield strength of 930~970 MPa, tensile strength of 980~1 050 MPa, elongation rate of 13%~15%. The impact energy is more than 100 J, and the mechanical properties are excellent.
In this paper, the critical points Ac1 and Ac3 of Q690D steels with different boron content were measured by Formastor-F automatic phase change meter, and the continuous cooling transformation curve of Q690D steel was drawn. The result shows that the addition of boron made the Ac3 and Ac1 of Q690D steel increased slightly, Ms point and Bs point reduced, the critical cooling rate of Q690D steel decreased, however the hardenability improved obviously. Boron in Q690D steel has different degrees of delayed effect on proeutectoid ferrite transformation and bainite transformation, which inhibits the precipitation of proeutectoid ferrite. The complete bainite structure can be obtained in a wide range of cooling rate.
In this paper, the factors influencing the accuracy of the detection result are found out by analyzing the oxides cleanliness (K method) detection process for the exported rails. And the control measures are put forward to ensure the accuracy of the detection result.
The uncertainty in measuring result for metal Charpy impact test is evaluated with N80Q steel standard V type impact specimen as an example. The measurement uncertainty which can affect impact testing results is analyzed in detail. The components are calculated, synthesized and evaluated.
According to the requirements of 30CrMo steel pipe cold drawing performance, the 30CrMo steel pipe was normalized and annealed in the laboratory, of which the microstructure and mechanical properties were compared and analyzed after different heat treatment. The experimental results show that the microstructure of test steel after normalizing heat treatment is bainite + ferrite pearlite, and the mechanical properties of the material are hard to meet the requirements of cold drawing process. By using the annealing heat treatment process, both the microstructure and the mechanical properties of the material can meet the cold drawing process requirements.
The X70 pipeline steel of Baotou steel, its corrosion of the steel pipe surface is not serious after three years of exposure in the open environment and has similar corrosion morphology characteristics of the weathering steel. While placed in the same environment, the same time, the X70 pipeline steel of the domestic steel plant, its surface corrosion is more serious. In the paper, behavior rules of resistance to atmospheric corrosion for X70 pipeline steel of Baotou Steel are studied by using the cycle corrosion test for the comparison between the X70 pipeline steel produced by Baotou Steel and the domestic steel plant.
In the paper, seamless steel tube of No.20 high quality carbon structural steel which produced by Φ460 mm PQF continuous rolling mill in Baotou Steel is studied. Aiming at the situation that the yield strength of rolled seamless tube is low, the causes of the low yield strength are analyzed from the material specification, chemical composition, mechanical properties and their correlation. And the improvement measures are put forward to ensure the quality of the steel tube.
In the paper, it is introduced the large vibration of the slag vertical mill occurred in the early trial production, by adjusting the system volume, water volume within the mill, roller pressure, increasing process equipment, appropriately adjusting the dam ring height, proper control of feeding, appropriately adjusting the rotating speed of the separator and a series of technical measures to ensure that the operation results of slag vertical mill meet the design and requirement of production process.
The converter shell is an important component of converter body. The 150 t converter shell discussed in this paper is the main equipment in Steel-melting Plant of Baotou Steel. Its production process is the direct impact on the safe use and the expected useful life of the converter. Through the production practice of Baotou Steel Mechanical Equipment Company, test the rationality and feasibility of production process to meet the technical requirements of drawings and the requirements of relevant standards.
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