Latest ArticlesIn this paper, it is introduced the BT150P perforating gun pipe produced with hardening and tempering by Baotou Steel as well as summarized the situation and effects of developing it through designing steel grade, technological test of heat treatment and actual production. The results showed that the perforating gun pipe reached 150 KSI strength level and was with high strength and ductility by the proper heat treatment.
In the paper, the composition design scheme of non-quenched and tempered 36Mn2V steel for drill pipe is put forward and the optimum range of composition is found out through such research methods as mechanical property tests and metallographic analysis. The industrial tests prove that the performances of the steel pipe could meet the requirements.
The hot rolled steel strips products with different specifications for H40 welding socket in most domestic markets are designed with the same C-Mn composition system. Further, the production technologies for special specification of each grade of steel strips are worked out through controlled rolling and controlled cooling process so that the hot rolled steel strips with excellent mechanical properties are manufactured.
In order to eliminate the defect of fish eye on the surface of outer ring of cold rolled material after pickling rolling process, its micro structure and component were analyzed with the metallographic microscope, scanning electron microscope and energy spectrum as well as the effects of straightening and withdrawing weld joint on the defect were compared. The results showed that the defect was the iron matrix and the oxygen was not detected. There were different degrees of fish eye and porphyritic defects on the steel coils at the outlet of tandem mill observed when passing the weld joint without the stretcher leveler, while the defects were not found on the surface of steel coils when passing the weld joint in the stretcher leveler, so the problem could be solved by setting reasonable elongation of straightening and withdrawing.
The hot rolling process for thin plate of CSP of Baotou Steel was studied with the thermal simulation test machine in this experiment. The test results showed that the higher the coiling temperature is, the greater the rolling speed is, the higher the finishing temperature is, the bigger the grain size is after rolling; it is better for grain coarsening to distribute the reduction ratio from big to small. The test results provide the experimental evidence for rolling the qualified base material for cold rolling with the CSP technological conditions.
In the paper, it is found out that the defects at bottom of notch of impact specimen caused by improper processing lead to the test force forms stress concentration again at bottom of notch of specimen in the impact test through analyzing the reasons for the abnormal test results of impact property for J55 casing pipe of Baotou Steel. The normal stress at the notch of impact specimen exceeds the cohesion strength of material before the specimen deforms so that the specimen is easy to tend to brittle rupture and the impact energy of material is decreased in the actual detection.
In the paper, it is introduced the modeling and finite element simulation analysis on driving roll are carried out with the system parameters of rubber belt vacuum filter and finite element analysis software ANSYS. The structure and stress parameters for driving roll of rubber belt vacuum filter during its operation are obtained as well as the optimization measures are further put forward.
In this paper, the main reasons for low efficiency of 15MW condensing steam turbine are found that the salification and scaling of its flow passage and inlet nozzle as well as the foreign matters plug some inlet nozzles through analysis combining with the working conditions of productions. Moreover, the causes for salt deposit are further analyzed and the prevention measures are put forward. The overhaul plan for opening cylinder of turbine is summarized, the salt deposit of flow passage and inlet nozzle was cleaned up with the high-pressure spray as well as the foreign matters in the inlet nozzles were taken out with the endoscope and dust collector. Finally, the fault was solved.
The stable and high efficient operations of the electric control system for hoister of dry coke quenching is helpful to promoting the development of dry coke quenching technology and could provide reliable conditions for the stable operations of electrical equipment. In this paper, it is briefly introduced the electrical control system for hoister, analyzed the electrical control principles from such two points of view as the control principle and development trend as well as further discussed the applications of control system of hoister in the industrial control and industrial productions aiming at promoting the efficient completion of the electric automatic control project for hoister of dry coke quenching, which are for reference only for the related personnel.
In the paper, three types of optical link pilot protection device applied in the microcomputer-based line of mid-voltage power system in enterprises in recent years are introduced as well as the effects of saturation of current transformer on the starting value of protection device and the requirements of communication for protection are expounded respectively according to the characteristics of mid-voltage power system in enterprises. Finally, some suggestions on the equipment selection for mid-voltage power system in enterprises and channel maintenance for optical link pilot protection device are given, which are with certain guiding significance for the actual work.
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