Adopting new technology to improve the continuous

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At present, the focus of the development of steel rolling technology in China is to continue to adhere to the policy of variety structure adjustment, establish the awareness of high-quality products, strive to develop high value-added products urgently needed in the market, and focus on product upgrading and production promotion. Therefore, adopting the following new technologies and processes to transform the existing alloy steel production line, improve product quality and reduce production costs has become a concern of alloy steel rod and wire manufacturers

hot delivery and hot charging technology of continuous casting billet

hot delivery and hot charging technology of continuous casting billet has the advantages of energy saving and consumption reduction, increasing the output of heating furnace, reducing secondary burning loss, reducing billet inventory and stacking area, and shortening the production cycle. Therefore, hot delivery and hot charging technology is also one of the topics to be considered in the construction of oil return valve and opening the piston of oil delivery valve of alloy steel rolling mill

many newly-built steel mills now adopt the compact production process of steelmaking refining continuous casting rolling. The hot delivery and hot charging between steel rolling and continuous casting are directly carried out through the hot delivery roller table, lifting device and insulation conveying roller table, which has become a common practice in general rod and wire production lines

precision rolling technology

rod and wire sizing mill, as a precision rolling technology for the dimensional accuracy control of alloy steel, has also attracted more and more attention from manufacturers. Its main characteristics are as follows: high dimensional accuracy and good surface quality of products; Free size rolling; Single pass system, easy to operate. Realize controlled rolling

there are usually 3-5 bar reducing and sizing units. The first few rolling mills play the role of extension deformation, and the last two rolling mills play the role of sizing. The pass of 4-stand rolling mill is an elliptical circular circular system. After using the reducing and sizing unit, the dimensional tolerance of the product can be controlled within ± 0.1mm, or even ± 0.5mm, and the ovality can be controlled within 60~80%. In this way, the tolerance value reached in the secondary cold processing can be achieved, so some machining processes can be omitted or simplified

low temperature finish rolling technology

low temperature rolling (start rolling temperature ~950 ℃) is an effective rolling method that can save energy, refine grains, reduce burning loss and metal decarburization. However, due to the high requirements for mechanical strength and transmission capacity, the formation of "banded structure" in the deformation of metal structure is more serious, the tendency of material properties is increased, and the fatigue toughness is greatly affected. Therefore, Low temperature rolling technology is being promoted due to the constraints of equipment and other factors under the cycle of demographic dividend

low temperature finish rolling is a controlled rolling method that uses the same rolling temperature as the conventional rolling process in the rough and medium pre finish rolling unit, and controls the temperature and deformation of rolled pieces in the last 2~4 passes of finished product rolling, so as to improve the structure and performance of products

single pass rolling and "free size" rolling technology

bar and wire production lines equipped with reducing and sizing mill are generally used to roll the finished products from the reducing and sizing mill. When changing the specification, it is only necessary to adjust or replace the roll and pass of the reducing sizing machine, and the upstream mill passes in turn to realize the rolling of a single pass system

the main characteristics of single pass rolling are as follows: when changing the product specification, the mill upstream of the reducing and sizing mill passes empty, and there is no need to adjust it. Only the reducing and sizing mill is adjusted, and the replacement specification time is short and the efficiency is high; All specifications are rolled out from the reducing and sizing mill with high precision; There are few guide and production spare parts, which simplifies the production preparation

"free size" rolling: when reducing and sizing mill is used for rolling, products of adjacent specifications can be produced only by adjusting the roll gap of reducing and sizing mill without any change of other mills, which can greatly shorten the downtime when changing product specifications. For kocks three high mill, the adjustment range of product diameter reaches 9% of the nominal diameter of the product. For wire tekisun reducing sizing machine, the size range of "free rolling" is ± 0.3mm

the characteristics of "free size" rolling are as follows: greatly reduce the number of passes, and exchange and frame replacement times on the latest development trends of new material industry and relevant cities, cutting-edge research in industrial development orientation, the latest technologies and standards, etc; Reduce the number of spare rolls and guides; The productivity of rolling mill has been greatly improved; Continue to maintain high product accuracy

single pass rolling and "free size" rolling technology improve and improve the production efficiency from the process operation, reduce the production cost, and meet the needs of multi variety production of alloy steel, which can be used for reference in actual production

slow cooling technology for straight bars

there is a novel slow cooling technology for straight bars in the existing domestic production workshops. This technology is to use a shorter length of times the length of the cold bed when the rolled piece is put on the cold bed, and then quickly pass through the cold bed, and then the cold shear or grinding wheel saw will cut the length and segment, and the slow cooling collection box behind the sizing machine will directly collect the mild cooling

according to the design results, when the temperature of the rolled piece entering the cooling bed is 950 ℃, the length of the fixed length is 6.0m, and the length of the double length is 36.0m, the temperature of the rolled piece of the bar with diameter ≥ 20mm entering the slow cooling box can be maintained at ~470 ℃, which can meet the slow cooling requirements of martensitic bar

straight bar burring technology

after being divided by the grinder, metal flying thorns are left at both ends of the finished bar, which brings great inconvenience to the baling molding and subsequent finishing processes. Deburring, neat and beautiful appearance of the bundle, simplifying the subsequent finishing process, is very beneficial to improve the quality of bar packaging

deburring is carried out by the deburring machine set on the transverse conveying bench. According to the diameter of the bar, two deburring processes are adopted

bars with a diameter ≤ 25mm: the cut to length materials are sent to the deburring position in rows by the conveying chain, and then the rolled pieces are aligned on the deburring machine head by aligning the roller path, and then the pressing chain drops and presses the bars, the chain operation drives the bars to rotate, and the head of the bars is rubbed on the wire brush to remove the burrs, so as to obtain a smooth head shape. When one end is deburred, the layered bar is moved out of the first deburring position to the alignment roller path, so that the other end is aligned and deburred. Bar with diameter ≥ 25mm: the sizing material is sent to the separation place of single bar by the conveyor chain in rows, and then sent to the deburring position by the stepping mechanism. The alignment roller table is aligned at the deburring machine, the pressing device presses the bar, the deburring machine head rotates, and the bar head is rubbed on the wire brush to remove burrs, so as to obtain a smooth head shape. After deburring one end, the stepping mechanism moves out of the first deburring position to the alignment roller path to align and deburr the other end. After deburring at both ends, the bar is moved forward by chain to collect and bale

large size deburring machine is a device with three steel brush heads, which can deburr three rolled pieces at the same time (small size deburring machine is a strip steel brush head device). The brush head can be adjusted radially, and the whole deburring machine can be moved laterally. When not in use, it can be moved out of position, and the layered bar can continue to be transported for collection

loose coil solid solution treatment of wire rod

for austenitic stainless steel with less stringent final use quality requirements, such as springs, steel ropes, and some occasions requiring high strength but not very high toughness, as well as as as the pretreatment process of final heat treatment, the waste heat of rolling can be directly used for loose coil solid solution treatment to save energy consumption and reduce production costs

the loose coil solid solution treatment method is to set a section of high-pressure water nozzle or cooling water tank with a length of ~10m above and below the roller table in the swing section due to the long service time of the buried cable. When the coil enters the water-cooling section, the nozzle sprays water or enters the water tank at the same time, so that the austenitic coil can be cooled quickly to meet the requirements of solid solution. The cooling water after solid solution is collected under the roller table and pumped to the water treatment station for recycling

austenitic stainless steel coil ring furnace solid solution treatment

in order to make full use of rolling waste heat, save energy consumption for secondary heating of offline solid solution treatment, reduce production costs, and obtain austenitic stainless steel coils in good solid solution state, the ring furnace treatment process is set. The capacity of the annular heat treatment furnace should match the production capacity of the rolling mill. The solid solution heat treatment process of the annular furnace is as follows: the collected hot austenitic stainless steel wire coil or the rolled large coil is sent to the charging machine of the annular furnace by the conveyor, and the charging machine sends the coil to the annular furnace. The coil is heated and insulated to 1050 ℃ ~1080 ℃ in the annular furnace, and then taken out by the coil unloader and sent to the circulating cooling water tank at the outlet side for quenching and solution treatment. The coil temperature after the water outlet tank is ≤ 100 ℃, and then it is sent to the p&f line by the conveyor for baling and collection. (end)

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