1 Analysis of the roll material selection module The quality of the roll is very necessary for the industry, which requires good quality control of the strength and its working layer to ensure the overall wear resistance is optimized. This requires an analysis of economics and its associated performance. Guarantee the control of the roll change cycle and its downtime, ensure the control of each unit, and meet the deformation work needs of the mill. This also requires an increase in the overall accuracy of the product, meeting the needs of the comprehensive work of the sorting, and ensuring the optimization of the overall performance of the roll. This requires a clear understanding of the task of the bar roughing stand, the control of the surface under high temperature conditions, to ensure that the roll is subjected to the improvement of rolling efficiency, and to ensure the control of the depth and pressure of the rolling. This requires the roll neck of the roll to have good strength. It guarantees the excellent rolling speed of its rolls. After all, in the working module, it must also be in sufficient contact with the steel of a certain temperature. In the contact module, it is necessary to ensure the good heat resistance of the structure, thereby achieving the improvement of the overall thermal crack resistance, optimizing the anti-flaking property, ensuring the improvement of the overall impact, and performing the bite analysis to ensure the machine. The good choice of the frame, to meet the needs of the current work construction, improve its application efficiency, ensure the overall performance of the rack to improve, to achieve the relevant work tasks at this stage. In the current working module, the bar mill is an important module. By controlling the elongation of the rolling stock and the accuracy of the finishing unit, it is more conducive to the complete control of the rolling mill and meet the needs of the equipment. This also requires the analysis of the working position of the groove, the control of the rolling force, and the improvement of the overall strength of the roll and its optimization, which requires the attention of relevant personnel. However, due to the large size of the roll hole, the cooling of the bottom of the groove cannot be fully achieved. Therefore, it is required that the roll at this position needs to have good thermal crack resistance and impact toughness, and also has corresponding wear resistance. According to its location, its wear resistance is higher than that of the roughing mill. In particular, the hardness of the bottom of the tank and the top of the tank are not much different, basically the same. It is appropriate to use the centrifugal composite roll here. In the current working module, the bar finishing mill has a wide variety of rolling, its shape is more complicated, and its rolling force is also changed to a greater extent. By optimizing the performance of the roll, it is more conducive to improving its toughness and Its wear resistance ensures an increase in its overall crack resistance. This requires an increase in the working efficiency of the rolling mill, the control of the number of roll changes, and the improvement of the overall surface quality of the steel, which requires application to a series of special materials. The 70-75HSD needle-shaped bainite roll is made of many materials, and the bainite material molten iron needs to be spheroidized. This kind of spheroidized molten iron is easy to spheroidize during the casting process, and the roll surface hardness is uneven, which makes it impossible to open the hole. Type, some even if it is barely applied to the machine, it will have to be scrapped because the products produced do not meet the process standards. It has an adverse impact on production. In the current working module, it is necessary to control the high-speed steel roll module, which requires analysis of wear resistance and hardenability, ensuring red-hardness control at high temperature and ensuring the overall quality of the roll. In general, it is more advantageous to control the strength by improving the performance of the acicular bainite ductile iron roll. This requires a relevant working module. The working layer of the high-speed steel roll contains a large amount of alloying elements such as tungsten, chromium, molybdenum and vanadium, among which the carbides are high-hardness MC type fHV2000-3000) and M6C type (HV1500~). 1800), the matrix structure is tempered martensite + bainite, and the matrix structure has higher hardness, finer structure and better wear resistance than acicular bainite ductile iron. The strength and wear resistance of high-speed steel rolls require more reasonable control of the machining tool, analysis of the turning parameters, control of the cutting head of the turning module, such as the application of carbide turning tools, turning The speed control ensures the control of the feed amount, optimizes the feed depth, and ensures the turning speed and the depth of the feed. However, when turning with a PCD turning tool, it should be cooled. The coolant should be applied before entering the cut. When rolling ribbed bars, the ribs need to be milled on the groove, and the tool can use CBN or YD05 milling cutter or Swedish Sandvik tool. Due to the high hardness and high processing difficulty of the high speed steel rolls, the processing time is three to four times that of the alloy cast iron rolls. 2 Analysis of high-speed steel roll application module In the high-speed steel roll working module, it is necessary to analyze the material specificity to meet the needs of equipment cooling and meet the strict requirements of the equipment. Ensure the integrity of the rolling system and actively carry out the relevant roll cooling module. This allows analysis of the overheating of the rolls and better analysis of the peeling properties. It is also possible to control the roll surface temperature, ensure the optimization of the rolling surface structure, better meet the working needs of the current roll wear resistance and its quality, ensure the overall fatigue resistance control, and meet the heating work needs of the roll. It affects the wear resistance of the roll and the surface quality of the rolled material; the third is to prolong the formation of thermal fatigue cracks and prevent the expansion of thermal fatigue cracks. The heating of the rolls mainly comes from the contact with the rolled piece, and the deformation of the rolled piece also has a certain influence on the heating of the rolls. It is generally believed that the temperature of the contact zone between the rolling stock and the rolls is the average of the rolling stock temperature and the roll temperature. Therefore, the instantaneous temperature of the roll surface in contact with the rolling stock can reach about 500~C. In the nozzle working module, it is necessary to control the amount of water, which is inseparable from the optimization of the injection angle. For example, the lifting of the main nozzle is carried out, and the cooling water is cooled to ensure the control of the rolling groove. This also requires the control of the water pressure to increase the amount of water in the tank. In order to avoid excessive scattering of water, it is also necessary to analyze the solid ion content to ensure the optimization of the cooling scheme of the roll water cooling device. The amount of cooling water and water pressure, as well as the nozzle angle, are quite different. However, lowering the roll surface temperature, maintaining uniform temperature distribution of the roll cooling, ensuring the cooling effect of the roll surface, improving the service life of the roll and improving the surface quality of the roll It is all crucial. In the case where the cooling method and the water pressure are similar, increasing the amount of cooling water of the rolls has a significant effect on lowering the roll temperature and reducing the hot crack on the roll surface. In the current working module, it is necessary to carry out brittleness analysis of high-speed steel materials, which also needs to improve the overall capacity of the accident, ensure the effective development of the management module, and realize the normal operation of the rolling mill, so that the rolling accident can be controlled and more It is advantageous to carry out the control of the damage of the rolls. The optimization of the cooling scheme of the rolls is ensured, and the temperature control of the rolling stock is realized, which is more conducive to the control of accidents and ensures the optimization of the control modules of the rolls. Let it cool slowly, re-grind it and put it into use. Otherwise, if cooling water is poured onto the hot roll, serious consequences will result. The surface of the high-speed steel roll slot will form an oxide film during the rolling process. The oxide film will start to orange or light blue. If it continues to be used, it will turn into dark blue or purple black. When the oxide film is thickened to a certain extent or there is outside When scratched, the oxide film is easy to fall off, and meteor spots are formed on the surface of the slot. In severe cases, the roll surface is textured and even pitting occurs. There are many factors that lead to the change of the high-speed steel roll. In order to improve the work efficiency, it is necessary to carry out the anti-fatigue analysis of the module used for the groove, so as to better control the hot crack of the roll and ensure the normal use of the hot crack. It is guaranteed that the cracks will be completely repaired. This also requires the optimization of the crack control module to ensure the optimization of the overall control scheme of the rolls, and the analysis and control of the results of the high-speed steel rolls. The high-speed steel composite roll has been successfully applied in the bar mill of our factory. It shows the following advantages in the application: 1) It can improve the single-slot rolling amount, and it can be used for rolling single-slot rolling steel when rolling round steel finished frame. The amount is more than 2 times higher than that of the acicular bainite ductile iron roll.
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