抛丸清理机对板材轧辊进行抛丸处理外文文献翻译@中英文翻译@外文翻译

1 外文翻译原文 SHOT BLASTING MACHINES FOR THE BLASTING OF SHEET MILL ROLLS V. I. Meleshko, A. P. Kachailov, V. G. Boikov, V. L. Mazur, T. P, Kobka and I. I. Krivolapov At the present time much attention is being devoted to increasing the quality of rolled products, partieularly sheet. To a significant degree this depends upon the preparation of the roll surface. Many plants are engaged in improving the quality of working the roll surface in preparing them for rolling.This article was written by personnel from Zaporozhstal Plant, Magnetogorsk Metallurgical Combine, the Institute for Ferrous Metallurgy, Dnepropetrovsk, and Magnetogorsk Mining and Metallurgical Institute on this very real problem. The surface microrelief, or roughness, of cold rolled constructional sheet has an influence on the mechanical and production properties of metal, and also on the finish quality of parts made from this sheet. The final surface microrelief of thin sheet steel is formed in a skin pass on work roils which have been given a rough finish with metal shot. Normally the rough surface finish on the work rolls of skin pass stands is produced in pneumatic and rotor shot blasting machines. Experience in their use has shownthat the pneumatic machines used in the countrys steel plants do not fill the need for high quality blasting of roll surfaces. In 1969 the Institute for Ferrous Metallurgy, Dnepropetrovsk, did work on the SM-2 shot blasting machine in No. 1 Cold Roiling Mill of Zaprozhstal Plant, which revealed a number of shortcomings in its construction. To provide sheet with the surface roughness required by the specifications of Volga Automobile Plant (R a =0.8-1.6 g),the basic requirements for the design of shot blasting machines were determined, The machine must provide: 1. a constant shot size during operation, in other words, effective removal of shot of the specified size from 2 worn shot； 2. the possibility of controlling air pressure in the collector of the shot blast machine during stable operations； 3. the handling of work rolls of different diameters (400-500 mm) without special equipment on the machine； 4. simplicity in control and convenience in maintenance. Fig.1 The SM-2 machine (Fig. 1) consists of a stationary closed chamber ! with a trolley on wheels aad movab!enozzles 2 which under the action of compressed air discharge shot on to the roll surface, a worm conveyor 8, an elevator with a separator 4, the shot blast equipment 5, and an exhaust system 6. The equipment is mounted on a special foundation 1905 mm below the floor level The length of the machine withthe trolley out is 15fl00 ram, the height 4070 ram, and the width 4600 mr The dimensions of the rolls handled are 400-500 mm in diameter and 2000-4000 mm in length. The total weight of the equipment is 15 tons. As research has shown, the dynamics of the wear of a working mixture of abrasive and the original condition of the shot changes during operation. During blasting, the shot takes on a wider size range and is worn down, forming many fine particles. The conditions under which the parts are blasted depend upon the size of the shot used. The contamination of the specified size by fine particles disrupts the process, producing a poor quality surface on the rolls and consequently on the sheet. To eliminate these problems it is necessary to either 3 regularly measure the composition of the shot and make appropriate changes in the blasting sequence, which is difficult to do in practice, or to screen the shot during operation of the machine to provide the specified particle size. Stability in the blasting process is also determined by the quantity of shot delivered to the nozzles. It was experimentally established that supplying 0.3-0.4 kg/sec of shot to the two nozzles in operating with an air pressure of 2.5-4.0 atm provided stable operation. Equipping the machine with screening devices is an effective method for maintaining a constant shot size mix. This is confirmed both by data in the literature and by experience in the operation of SM-1 and TsKb_P-1 shot blast machines at Zaporozhstal Plant. The shot is delivered to the surface of the roll by the shot blast equipment, the chamber of which is divided by two diaphragms with charging vents into three compartments and is equipped with an electropneumatic control device. The working mixture from the upper compartment of the chamber drops to the lower and then to the collector. During operation of the machine,the vents are closed (turned on). The shot is poured in either after turning off the valves by the electropneumatic control device, or after shutting down the machine by the operator. When it is turned off, the vent descends, and between it and the diaphragm a circular gap 5 mm wide is formed. The vent is a cone with a slope of about 30% The shot drops slowly through this gap but not completely, and therefore it increases to t0 ram. The loading vents are alternately turned on by the control device. The first time the SM-2 machine was repaired, it was discovered that the control device frequently did not operate because of corrosion of the parts. With normal charging of abrasive (375 kg according to the nameplate), blasting must be stopped after each alternate pass of the nozzles, since after another pass the shot in the lower compartment is insufficient, and during blasting, With nonoperation of the control device, it does not drop from the upper compartment to the lower. Delivery of the nextportion of shot must be done only after the operator disconnects the shot blast equipment from the air system. In this case both charging vents are opened, and the abrasive is fed to the lower compartment. Continuous operation of the machine for three or four passes of the nozzles with nonoperation of the control device and the delivery of shot described above became possible after increasing the standard charge to 650 kg. However, the basic solution of this problem is stable operation of the control device. The used shot is collected by the collecting bunker of the working chamber and drops into 4 the receiving chute of the worm conveyor. The plates parallel to the worm conveyor are at a greater angle, and those perpendicular are at less of an angle, which tends to collect shot on them. Therefore, after blasting one roll it is necessary to shut the machine down to push the accumulated shot on to the screw conveyor. To eliminate this shortcoming, it is possible to lengthen the screw conveyor, which is half the length of the working chamber. In addition, the smaller plate is removed completely,and the parallel plates are elongated to correspond with the length of the worm conveyor. The compressed air supplied to the collector of the shot blast equipment is dried by an oil moisture separator. However, this method of drying is inadequate. Water vapor condenses in the main line and in the shot blast equipment, and as a result shot sticks together in the lower compartment and forms a solid mass. The solid mass clogs the vertical channels along which the abrasive is transported to the collector and disrupts the optimum ratio of shot to air in the blast. This has a detrimental effect on the blasting process and the quality of the roll surface. The presence of moisture in the air causes corrosion of the equipment and causes operation of the pneumatic equipment of the machine to be poorer. Therefore, in designing shot blast equipment,it is necessary to specify equipment for drying the air. Foreign firms, for example, use special drying equipment utilizing water absorbing substances such as silica gel and activated alumina for drying compressed air. 5 The mechanism for moving the nozzle has a number of shortcomings. Application of the jet of abrasive material on to the roll is through a nozzle mounted in an elbow shaped gun (Fig. 2). A shortcoming of the gun is the throttling of the mixture of compressed air and shot where the vertical and horizontal channels join. The junction is a right angle, which causes quick wearing away of the elbow. The cross sections of the channels and nozzle was increased. However, with an increase in the nozzle diameter from 10 to 12 mm (the allowable maximum) the consumption of air increased from 13 to 19 mS/h, which changed the ratio of shot to air in the blast. However, thisratio must be kept constant. Since during blasting it is difficult to make corrections, it was necessary o improve the design and increase the wear resistance of the parts. Fig.2 For this purpose a new design of blast guns, in which the diameter of the channels was increased (Fig. 2 b) and the shape of the transition from the channel to the channel and nozzle was changed, was proposed and tested, The new nozzle design is much more effective. After five months of operation,noticeable signs of wear in the elbowand nozzle have not been found, while the old design elbows wore out in a month. 6 The blast guns are moved along the roll by a conveyor belt. Under the action of the weight of the troJ.ley and oscillations caused by its movement along the guides on which shot falling from the surface of the rolls accumulates, the belt gets out of alignment. As a result, the impact of the stream of shot on the surface is not at a right angle, but glancing, which produces a poorer surface quality. Placing a strip under the gun eliminated this problem, and the roll surface quality became satisfactory. In the first period of operation the compressed air tn the SM-2 machine was obtained from the shop main i,ine, which has a pressure of 6 atm. According to readings on a manometer placed before the collector of the shot btaat unit, the air pressure in it did not exceed 4.0 aim. With this pressure, even with the use of the finest shot (DChK-0.8), the roughness of the rolls is at the upper limit (R a = 2.7 #). Therefore, it was necessary to reduce the working pressure of the air. An air valve was used to control the pressure, but it was very sensitive to changes in air pressure, and operation of the shot blast machine was unstaSle. As a result, a reducing valve was placed between the oil moisture separator and the shot blast equipment. This made it possible to control the air pressure in the collector from 4.0 to 2.0 atm with an accuracy of 0.1 atrr. The use of this valve provides stable operation of the shot blast equipment. To blast rolls of different diameters it is necessary each time to change the position of the blast gun, which is not provided for in the design of the SM-2 machine. For example, at the present time to blast a 400 mm diameter roll after a 500 mm roll the machine must be shut down for adjustment. In designing new shot blast machines the possibility of changing the height of the gun must be specified. To observe the blasting process, special observation windows were cut in the long wal! of the lighted working chamber. Nonetheless, observation of the surface of the roll being blasted was difficult. Therefore, three additional 500 W lights, protected by louvers, were placed on the ceiling of the working chamber. 7 Fig .3 Control of the machine (Fig. 3) is from the control panel 2, the valve 5 at the air line, the rheostats for con. trolling the speed of rotation of the roll and the movement of the nozzles, and the push buon for starting up the exhaust fan motor, which is behind the machine. Such an arrangement of the SM-2 shot blast machine equipment is not convenient for control The rheostats for controlling the speeds do not have graduated scales, which makes choice of the correct speed difficuR. Actual: 15 for each new position of the control handle it is necessary to determine the speed. These disadvantages must be eliminated in the design of new machines, It is also necessary to improve removal of accumulated metal dust from the horizontal portion of the exhaust line, which is in a difficult to reach location about 4 m above the floor tevel. To provide more convenient placement of the individual units of the shot blast machine and simplify imaintenance, the Institute of Ferrous Metallurgy has developed and turned over to Zaporozhstal Plant recommendations which have been partially put into use on the existing machine and will be studied in designing similar new machines. The improvement in the SM-2 pneumatic shot blasting machine has made it easily possible to controt and maintain the specified sequence for blasting work rolls for cold rolling and skin pass sheet stands. As a result, Zaporozhstal Plant is mass producing cold roiled constructional sheet with a surface roughness meeting Ferrous Metallurgy Technical Specifications 1-683-69 and 1-686-69. 8 外文翻译译文 用抛丸清理机对板材轧辊进行抛丸处理 V. I. Meleshko, A. P. Kachailov, V. G. Boikov, V. L. Mazur, T. P, Kobka, 和 I. I. Krivolapov 目前，轧制品的质量受到许多关注，特别是板料。这 从相当大的程度上 取决于 轧辊表面处理 。许多公司着手提高轧辊表面处理的质量，为辗压作准备。这篇文章的作者来自 Zaporozhstal 公司 ， Magnetogorsk 冶金联合企业的人员 ， 有色冶金研究所 , Dnepropetrovsk 和 Magnetogorsk 采矿和冶金学院 ，来研究这个现实的问题。 微表面质量 ，或粗糙施工的冷轧板，对 金属的 机械 性能 和生产性能 ，也对来自于这块板料部分的最终质量有影响。 薄钢板 最终 微 表面的形成是通过对已用金属球粗加工过的表 面进行工作辗压得到的。 通常情况下，对不合标准表面的工作辗压粗加工是由 气动力学和电动 抛丸 清理机完成 。 在使用中的经验表明国家钢铁厂使用的气动机不能满足辊板表面抛丸处理的高质量要求。 1969 年， Dnepropetrovsk 冶金研究所在 Zaprozhstal 厂 1 号 冷的混乱的磨房 研究了 SM-2 型抛丸清理机，发现了一些它结构上的缺点。 为了提供 符合 伏尔加汽车厂表面粗糙度 要求的板料（粗糙度为 0.8-1.6u） ,用于抛丸机设计的基本要求是确定的。机器必须满足： 1. 在操作时一个持续的喷丸尺寸，换句话说，有效去除已磨 损弹丸的既定尺寸； 2. 平稳操作时，控制抛丸机收集的空气气压的可能性； 3. 在机器没有特别的设备时，对不同直径（ 400-500mm） 的工作辊的处理； 4. 控制简单，维修方便。 9 图一 SM-2 抛丸机（如图 1）是由一个装有轮子的固定的封闭室 1，一个可移动喷管 2（ 2 在压缩空气的行动下，对轧辊表面发射弹丸），一个蠕虫输送机 3，有分隔的传送机 4，抛丸装置 5，和排气系统 6 组成。该设备安装在一个低于地面水平 1905 毫米的特殊地基上。有小车的机器的长度是 15， 200 拉姆 ，高度是 4070 毫米，宽 度 4600毫米。操作的辊的尺寸是直径 400-500 毫米，长度 2000-4000 毫米。整台设备的总重量是 15 吨。 研究表现了操作中 一个工作 中 混合磨料磨损的动力 和弹丸变化的原始情况。在抛丸时，弹丸在一个更大的尺寸范围内变化，磨损，形成许多微粒。在这种情况下，零件的抛丸取决于所用弹丸的尺寸。特定大小的微粒污染会破坏抛丸过程，使辊表面以及最后板料上的表面粗糙度降低。为了解决这些问题，有必要既定期地检查弹丸构成，在抛丸过程中做适当调整（在实际中很难做到），又要在机器运行过程中筛选弹丸以提供特定大小的微粒。 抛丸过 程中的稳定性也是由送入喷管的弹丸的数量所决定的。实验表明，在气压2.5 -4.0atm 下 ,提供 0.3-0.4kg/sec 的弹丸到运行的两个喷管中可以使操作稳定。给机器装配一个筛选装置是一个保持弹丸尺寸的有效方法。理论上的数据和Zaporozhstal公司在 SM-1 和 TsKb_P-1抛丸清理机的实际操作经验都证实了这一点。 10 弹丸通过抛丸装置传送到辊表面，机器的封闭室被分为两个隔膜间，每间分为三格，并配备一个电子气动控制装置。 工作混合物 从上格式 下降到较低的，然后收集。在操作机器时，排气 口被关闭（打开）。 弹丸要 么在电子气动控制装置关闭阀门后送入，要么在操作者关闭抛丸机以后送入。当机器关闭时， 出气孔下降，并且在它和膜片之间 形成了 一个圆空 5 毫米宽 的圆孔。排气口是一个大约有 30 度的锥体，弹丸慢慢通过这一缺口，但不完全，然后弹丸直径减少到 10 毫米。装载喷口由控制装置轮流打开。首次维修 SM-2 抛丸机时，发现由于零件的腐蚀，控制系统经常不运行。 正常磨料（根据铭牌三百七十五千克）， 在交替通过每个喷管后必须停止抛丸，因为 之后 另一个 通过 弹丸 的低射舱室是不够的 。在抛丸时由于控制装置不运转，它不能从较高的舱室下降到较低的。仅仅在操作者 将抛丸设备从空气系统中分离后，下一部分的弹丸才能被送过来。在这种情况下，两个掌管的通风口都必须被打开，磨料要被送到较低的舱室。机器的连续工作使磨料通过没有控制装置的三至四个喷管，在磨料增加到标准要求 650kg 后，上述弹丸的运输才变为可能。然而，解决这个问题的基本方案还是控制装置的稳定运行。 可用的弹丸是由工作室的收集舱收集的，然后落入蠕虫传送机的接受槽。平行于蠕虫传送机的板材处在一个更大的角度， 而那些垂 线 正处于一个角度，倾向于收集 朝它们射来的弹丸 。 因此，在对一个辊板进行抛丸后有必要关闭机器将累积的弹丸推到螺 旋传送器上。为了消除这个缺点，将螺旋传送器加长到工作室长度的一半是可行的。此外，更小的板料已经完全消除，平行板被拉长以符合蠕虫输送机的长度。 提供给抛丸设备收集室的压缩空气被油水分离装