Latest ArticlesIn this paper, it briefly introduces the production process and trial production results of high strength weather-resistant H-beam for railway carriage. The results show that the technical indicators such as chemical components and mechanical properties of the steel reach the standard requirements and meet the requirement of steel for carriage.
In this paper, it aims at optimizing the different tension control methods for rough rolling, pre-finishing and finish rolling unit of high-speed wire rod mill, ensures that there is no pile-up accident due to the change of outside rolling conditions, reduces the defects of head and tail rolling edge as much as possible, in addition to improve the size accuracy grade of products.
Bayan Obo West Mine is a large open pit mine, in which there are a lot of iron bearing rocks in the open pit mining boundary, and how to make use of iron bearing rocks to turn waste into treasure has become the key factor for enterprises to increase their resource utilization. In this paper, the systemic experimental study of beneficiation on iron bearing rocks in Bayan Obo West Mine is carried out, the scientific beneficiation method is used to complete the theoretical research for the comprehensive utilization of iron bearing rocks in the laboratory, which provides important basis for the design and industrial application of the beneficiation plants.
In this paper, the experimental study on FMG western ore fines substituting for Maota ore fines is carried out by using the sintering cup, and the sinter quality indicators and high temperature metallurgical properties of different substitution ratio are systematically studied. The results show that the FMG western ore fines can be used to substitute Maota ore fines in sintering production. On the premise of ensuring the stability of sinter quality indicators and high temperature metallurgical properties, it is suggested that the substitute proportion of FMG ore fines for Maota ore fines should be controlled within 12%.
In this paper, through the high power microscopic analysis for the scars on the outer surface of 15MnNbV pipeline, it is found that the defects of steel pipe are mainly caused by surface cracks on the round billet. According to the cause analysis of cracks on the round billet, it comes to a conclusion that the surface cracks on 15MnNbV round billet are mainly due to the low straightening temperature. Through the optimization of continuous casting process, it can be seen from the trial production effect that the improvement scheme has solved the surface crack problem of round billet.
The Q345E high strength low alloy structural steel is developed by advanced steel making, continuous casting, double stand rolling and cooling processes in heavy plate production line of Baotou Steel. Two component design schemes are adopted to produce Q345E. The result shows that the steel plate is uniform in structure and good in performance, which meets the requirements of the national standard. Through the comparison of the key processes, performance results and process costs of the two component design schemes, the theoretical basis for the formulation of Q345E process is provided.
In the thrusting block process of 20Mn2 seamless steel tube, there are fine cracks in the corner. The tube is inspected through chemical composition test and macroscopic examination of hot acid etching, the micro structure is analyzed by means of metallographic microscope and scanning electron microscope. The analysis shows that the nonmetallic inclusions are the main cause of cracks, and the qualitative analysis of the inclusions is made to find out the source and to put forward the corresponding improvement measures.
The effects of different normalizing temperature and holding time on the microstructure of Q345E with 65 mm thickness have been studied by optical microscope. The results show that: Compared with the controlled rolling and controlled cooling (TMCP) steel plates, steels normalized at 900 degrees, grains are fine and the whole cross-sections are the most homogeneous. With the prolonging of holding time, ferrite grain growth is not obvious but pearlite content decreases, having spheroidization trend.
Experiments are carried out on DP540 and DP590 using different types of welding experiments, and the mechanical properties and microscopic metallographic structure are compared to find out the reasonable welding technology. At the same time, the deposition efficiency and welding bead formability, change of spatter amount under different process parameters are studied. The mechanical properties and diffusible hydrogen content of the tested welding materials were tested. The mechanical properties, fatigue strength and residual stress of the weld joint after ultrasonic impact (UIT) treatment are studied.
In the paper, the heat treatment process scheme of 25CrMoRE steel is worked out. Under the corresponding of heat treatment process, the technical parameters of 25CrMoRE such as yield strength, tensile strength, elongation, impact energy, metallographic structure, inclusion and grain size are measured by the relevant experimental equipment; the data indicators are analyzed and the influence law of heat treatment process on microstructure and properties of 25CrMoRE steel is discussed.
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