Latest ArticlesIn this paper, the causes of rolling defects in HN700 mm × 300 mm H-beam are analyzed, and the methods of eliminating rolling defects are put forward. By reducing the rolling defects, the yield of HN700 mm × 300 mm H-beam is improved, and the experience of eliminating rolling defects in HN700 mm × 300 mm H-beam is applied to the H-beam production of other specifications.
The smaller the austenite grain in steel is, the better the mechanical properties of structure are after structural transformation. In this paper, the Gleeble-1500D thermal simulator is used to simulate the heat treatment process of rare earth high Nb steel, and the TEM observation and analysis are carried out on the test pieces to study the effect of rare earth on austenite grain size in different holding time. The results show that: Rare earth can effectively inhibit the austenitic grain growth in heating process and play a role in adjusting the grain stability. In addition, rare earth can reduce the temperature of precipitation phase and promote the dissolution of second-phase particles in austenite.
The expansion of the dumping plough working face is the process of continuous change, and the scale of the subsidence, landslide and other diseases is also expanding with the extension of the dumping plough working face. Therefore, in order to ensure the safe production of belt conveyor system, it is necessary to sum up a set of effective operation methods, which is conducive to the standardization of prevention and control of subsidence, and also to facilitate the normalization of management.
Iron, rare earth and niobium resources in Baiyunebo Iron Mine rank first in the world. The paper focuses on the present situation of waste dump from the rock transportation process and the rock stacking situation. In view of the digging, stealing and mining behavior, rare earth resources protection project has taken effective measures to protect rare earth resources and has achieved remarkable results. In the future, better protection of useful rock, scientific and rational use of mineral resources, is the responsibility given to us by history.
In view of the problems existing in the production process of No. 22 and No. 25 angle steel, the common guide is self-developed, the sliding guide is changed into rolling guide and the pass design and rolling schedule are optimized to avoid the scratch of angle steel leg, guarantee the size of finished product and effectively improve the quality and output of product.
This paper introduces the characteristics of cantilever type straightening machine, and describes the bending, bending deflection and torsion which are easy to produce in the straightening process. It also gives examples for quantitative analysis and summarizes the effective methods.
In the open-pit mining, high water level deep hole blasting often appears linear meter with large charge amount, stemming length is too long, unit explosive consumption is high, misfire, half explosion, foundation, chunks and other problems, and the higher cost, blasting site processing being difficult and the safety factor being low, which seriously affect the ore mining efficiency in mine. Through in-depth analysis of the key technologies such as performance of site mixed emulsion explosive, oil-water ratio adjustment and chemical sensitizing process, the corresponding improvement methods and control measures are put forward to improve the quality of explosives, so as to ensure the high water level deep hole blasting effect and to improve the efficiency of ore mining.
Germany SMS flat-vertical compound straightener introduced by Rail and Beam Plant of Baotou Steel produces defects such as straighting mark, torsion and straightening asymmetry of rails in the process of straightening rails. In the paper, it is analyzed the cause of defects formation, that is, roll pass of horizontal straightening roll, roll pass of vertical straightening roll and straightening processing have influence on straightening mark, torsion and straightening asymmetry of rails. Through designing reasonable optimization scheme for straightening pass and adjusting the method, the problem of rail straightening defects is solved.
According to the different requirements and focus of standard detection, the ultrasonic flaw detection of rail base metal is now divided into two types: online detection of production line and in service detection of rail track. The detection of primary defects arising from the rail base metal production and the detection of fatigue defects arising from the length of service time after track laying have many differences in main types and key parts of the detected flaws. Through the combination of online detection and in service detection of rail base metal, study the position of fine flaw detection and improve the flaw detection method as far as possible. Only in this way can maximize guarantee the flaw pick-out rate and flaw detection quality of rail base metal detection.
In recent years, with several domestic and foreign mixed loading truck explosion accidents occurring, the issues of safe use and supervision for mixed loading explosive truck are also increasingly prominent. In the paper, through the analysis of current security status of existing mixed loading emulsion explosive truck in Chemical Plant of Baiyunebo Iron Mine, the key problems affecting the safety of mixed loading emulsion explosive truck are found out and improved by means of technical ways to further enhance the safety in the process of mixed loading emulsion truck and supervision of emulsion explosive, so that the safety of emulsion explosives goes into a new step.
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