Numeric imitate technology produces medium application in large forging

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Production of introductive big forging has sheet, batches small characteristic. The labor power with the much need before production and raw material of material resources preparation, mould or complementary, early days investment is quite large, once the product discards as useless, will cause very big loss, the rationality that this makes to craft raised very tall requirement. When produce new product or making new technology, technologist often cannot decide according to experience whether technology is sound, the method that can use a large number of tests only undertakes study. Because large forging size is larger, undertake 1 ∶ impossibly the objective experiment of 1, and small experiment can have differred with actual production process sometimes big. And the result that physical experiment can give a process a certain level only normally, cannot understand whole process in the round, have certain limitation. As a result of these specialty that big forging produces, the current situation that in using advanced numeric imitate technology to change craft to establish a procedure, decides by experience only has important sense. Technology of 1 numeric imitate is in contemporary the flying development of the position in making and effect as computer technology, human society had entered information period. The computer and network changed people way of life not only, changed the concept that traditional machinery creates and method as much. Assist a technology as the computer (the wide application of CAX) , in each segment that the computer has produced to industry deep. It is OK that a contemporary product makes a process by the graph 1 will describe. When receiving manufacturing job, use system of CAD(Computer Aided Design) to have products plan above all, its design a result to will produce the feasibility of craft and rationality to undertake assessment to its by system of CAE(Computer Aided Engineering) , if its are not contented production requirement or place need cost are too high, in will returning CAD system, undertake redesigning: If passed the assessment of CAE, will use system of CAM(Computer Aided Manufacturing) to undertake actual production is made. Mode of this one production already received wide application in industrial developed country, and in recent years more offerred collateral project technology (Concurrent Engineering) and fictitious production technology (the new idea such as Virtual Manufacturing) and new method, make products plan, technology, production makes the computer such as the CAD in reaching management, CAE, CAM, CAPP, MRP assist a technology, through advanced IT union rises, achieve thereby shorten further products plan, production cycle, improve product quality, reduce cost, enhance the purpose of product competition ability. But no matter which kind of methods, CAD/CAE/CAM still is the core that whole computer assists a technology and foundation. Graph the crucial technology that technology of imitate of numerical value of sketch map of production process of 1 contemporary product is CAE. Through building corresponding mathematical model, can be in the mould of high take time or complementary before making, the analysis undertakes to the whole process of craft in the computer. Can wait for a method to get all sorts of information such as such as temperature, stress, load intuitionisticly through graph, data not only, and the blemish that can forecast a likelihood to exist; Undertake to different program through changing craft parameter imitate is analysed, can give the rule from the summary in the contrast of each plan, implement technology then optimize. Numeric imitate technology is in assure workpiece quality, reduce material to use up, improve manufacturing efficiency, shorten the respect such as trial-produce cycle shows incomparable advantage. In industrial developed country, numeric imitate technology already was considered as an indispensable link in production, in domestic numerical value at present imitate technology also walks out of the tower of ivory already, already gained huge success in actual production. The case that article place mentions, have clear manufacturing background, it is close come more than 10 years we use numeric imitate method to solve big forging to produce the relatively successful case in real problem. Technology of 2 numeric imitate produces medium applied example to begin from 80 time metaphase in large forging, the task series that department of engineering of Tsinghua university machinery teachs a leadership by Liu Zhuang is engaged in numeric imitate technology be on big forging production all the time applied research, had a large number of significant jobs. From steel ingot pouring, forging produces the heat treatment after reaching forge, the research job that has covered each link of production of big forging hot-working, it is OK to was finished with Yu Gang ingot caky process imitate and blemish are forecasted, forging process imitate and craft are optimized, temperature of process of temper by dipping in water, temper and the computational process that stress field analyses. Through producing the clasp of manufacturer with each, these programs already aborning got applied actually, computational result and actual condition fit be identical, proved the dependability of the program adequately. And used these software to had undertaken optimizing to technology of a lot of actual production, obtained remarkable economic benefits. The hot-working craft that these software can be big forging is made offer a comprehensive CAE solution, can raise the rationality that craft makes effectively, improve manufacturing efficiency. 2.

Caky process imitate and blemish cast 1 steel ingot well-known, big swaged forging is built in using steel ingot, put in shrinkage cavity, loose, be mingled with to mix commonly slant the blemish such as analyse. The existence of these blemish meets those who increase material to use up, and may affect sequel to forging working procedure. Understanding blemish is formed reach the rule that distributing, keep abreast of and offer sound ingot casting technology, quality of big to rising forging, shorten manufacturing cycle, reduce material to use up have great sense. Begin from 80 time metaphase, author and plant of the first heavy-duty machine cooperate, the temperature field of caky to steel ingot process had a large number of research, built steel ingot caky in conduct heat the mathematical model of the process. At the same time the calorific mechanism to agent of exothermic mixture, heat preservation undertook be discussinged deep, built corresponding mathematical model. On this foundation development gives a for a special purpose finite yuan of simulator MIPS. MIPS can analyse field of the temperature in caky process distributing, do not carve the niche of caky forward position at the same time certainly, and can calculate shrinkage cavity and loose position and size. Use this program to be opposite weigh what the manufacturing technology place of 220 tons of steel ingot undertakes to optimize, solved successfully loose the problem that enters ingot body. Graph 2 showed craft improves around, shrinkage cavity reachs loose imitate result. (　 of A) former technology (B) improves craft graph 2 220 ton the shrinkage cavity on steel ingot is loose the distributings to use MIPS software and combine orthogonal design method of blemish, undertook study to the influence of shrinkage cavity size to the craft parameter such as steel ingot structure, reached " the effect with loose to shrinkage cavity condition of ministry of rising head end is the most distinct, it is the coefficient of thermal conductivity of sidewall firebrick next, it is ingot body taper again, and ingot body ratio of height to diameter is affected not quite " conclusion. This produces the law to technologist control steel ingot, optimize craft to be able to have very great help. MIPS software is forecasted in the caky imitate of common steel ingot and blemish not only in gained a success, and successfully application arrives without steel ingot of rising head or small rising head, among the research of directional crystallization ingot and hollow steel ingot. It is especially in directional crystallization ingot, flow through introducing, passed simple procedure mediumly to undertake maths is described to caky process, can forecast those who give steel ingot well and truly to slant thereby analyse circumstance. In large steel ingot in caky process, the phenomenon that ingot mould occurrence crackle discards as useless even also nots allow to ignore. On the base that uses successfully in MIPS software, we developed the stress of ingot mould of three-dimensional steel ingot to analyse a process again, conduce to solve this one problem. 2.

2 forging the appearance that process imitate and craft optimize steel ingot to need to just can achieve product place hope through forginging, this is the one annulus with big forging crucial production, its success was affecting whole production directly. A few programs that develop previously, because be aimed at the process with specific some mostly, do not have modelling function, in mould motion or attrib border condition bring to bear on wait for a respect to existing very big limitation, versatility is poorer. Once encounter new issue, want to make bigger modification to the program normally, cannot satisfy forging process simulative need. Be aimed at this one problem, we use the commercial software with the maturity on the world, be like the way that ANSYS photograph ties, before using what ANSYS perfects, later period handles a function, solved ANSYS successfully to cannot have the difficult problem of reseau redraw, development went a 2 peace keeping to play plasticity three-dimensionally, play stick plasticity to be out of shape greatly forging generally process simulator. This program can be not had with ANSYS implementation seam compositive, had stronger versatility thereby. This software can describe many moulds and its campaign, control to load effectively; Can get the change of metallic flow, stress, meet an emergency not only, and can gain load strength, the mould gets the information such as force, conduce to the choice when making technology appropriate equipment, evaluate a mould wear away to be destroyed even. Be versed in to die forging more art integrated the characteristic of die forging and extruding craft, can make an appearance complex, hollow, without flash forging. In the past, the research of this respect uses physical experiment method more, if use,delimit on face of plumbic sample semmetry reseau or do times lower the experiment flow condition that will study a metal. As a result of how to modular forging appearance complex, hollow, and in close model the figuration inside antrum, influencing factor is more, the metal is out of shape process of going from place to place is very acuteness, complex, so these physical experiment methods are put in the limitation with particular move, if reseau law will lose action to be out of shape acutenessly, times lower the experiment also can cannot get clear metallic streamline to complex flow. More important is, pass these tests, can study to be out of shape the some respect of the process undertakes only, and the understanding that cannot get whole to be out of shape process; And the treatment as a result of the mould, debug take a lot of work take time, need much capital investment. And use numeric imitate method, can avoid these flaw completely, get whole be out of shape all sorts of information of whole process. As a result of the many characteristic to die forging, to its process undertakes numeric imitate has very great difficulty, and also provide quite representative. Because wait for diameter 3 appearance characteristic, its should be a three-dimensional problem to the process of die forging extrusion more, see a picture 3. Graph 3 wait for diameter 3 forging graph is make the problem simplifies, the article introduced model of planar meet an emergency, basically analyse two orthogonality to be in charge of axes place to comprise the metallic flow on symmetrical face and mould to get force case. Graph 4 indication simulation make clear as a result, in horizontal drift first in the plan of impact, squeeze when horizontal drift dozen when relying on the position, because flow quickly up,the preform metal of drift upside is met, can break away from horizontal drift, form a cavity between preform and horizontal drift thereby. This one result and actual tally must have comparatived, because imitate used plane to simplify model, go up in the size of cavity with still have a few differences actually, but imitate result still can announce give this technology be out of shape characteristic. The graph squashs 3 times 4 on the base that the imitate result of the process developed 2 dimension to analyse a process in the success, we had been developed those who be based on ANSYS is three-dimensional be out of shape greatly play plasticity, play stick plasticity program, can analyse issue of complex figuration of three-dimensional metal plasticity. The graph is shown 5 times to produce the numeric imitate result of craft of figuration of forge of Dui of law of large crankshaft TR. Through imitate computation decides horizontal feed speed and perpendicular feed speed are right effectively the influence of figuration, can help technologist decide appropriate rate matchs program, achieve the goal that optimizes craft thereby. Graph the imitate result of craft of forge of Dui of law of 5 crankshaft TR (equivalent plasticity metabolic distributings) last working procedure that working procedure of heat treatment of imitate of process of 3 heat treatment is hot-working, it is the crucial link that makes sure product interior quality, contented function asks. To make sure the quality of the product and function ask, avoid to produce greater leftover stress, of heat treatment craft make general apt use a bit more conservative method, it is one of time-consuming and longer working procedure so. Heat longerly, the use uping that heat preservation time can increase the sources of energy greatly greatly, also meet the time of protracted product throw on the market. If where,the premise that assures quality falls, shorten heat treatment machines man-hour, it is direction of a when improve heat treatment technology significant progress. A large number of research that come through 10 years work, the analysis that using numeric imitate technology to have technology of big forging heat treatment and optimize a respect, we gathered much experience and data. Special software NSHT can analyse develops heat treatment not only heat, quench field of the temperature in reaching temper process distributings, and can give out of stress distributing the metabolic process that reachs photograph state. Pass numeric imitate to be able to have more thorough, comprehensive knowledge to whole process not only, and can use pair of craft to undertake optimizing. We cooperate with one heavy group, use NSHT software to pledge to material the 6MW rotor craft that is 26Cr2Ni4MoV undertook optimizing. Graph 6 be the temper by dipping in water before improving, answer fervent disposal specification. Heat through be opposite, quench reach temper the imitate computation of different program makes clear: A quenchs standard of normative B temper pursues A of sketch map of standard of heat treatment of former technology of 6 6MW rotor.

In former technology program, to achieve save up quantity of heat, high speed is changed through austenite change the purpose of the area and can cancel 8 hours actually in 660 ℃ heat preservation, instead with heating appropriately speed is passed change area, enter heat preservation phase, can shorten heat the time of a need. B.

Former technology is hollow water cools alternately, oily finally Leng Ke stimulates Leng Zhixin ministry to exceed pearlite photograph to change with using water oil area, next air is cold change through appearance of substance of shellfish family name area, the operation goes to the lavatory to be able to satisfy the requirement of stress again already. C.

Heat in temper process reach heat preservation phase to be affected to the stress after temper bigger, and the influence of cooling phase is minor, because this can carry tower above furnace temperature spend the time with saving furnace; The heat preservation time of temper process has an optimal time, heat preservation basically already did not have action (stress reduces very few) . In temper below the condition that difference in temperature of inside and outside asks to permit, can shorten time of temper heat preservation. Undertook improvement to the craft of 6MW rotor according to above conclusion, already gained a success in actual production, shortened not only man-hour, simplified to operate, and function and stress level still can satisfy a requirement. This one craft improves a success to make clear, each segment that use NSHT to be able to analyse heat treatment craft effectively are in-house to forging the influence of quality, can make thereby of heat treatment craft make more reasonable, achieve economic man-hour, reduce cost, raise the goal of forging interior quality. Technology of 4 numeric imitate uses a trend that looks into advanced production technology in large forging production is all sorts of technologies effective ground is compositive, make its produce bigger beneficial result thereby. In light of the applied current situation that produces an industry from domestic big forging, rising CAD and CAE union is a reality and get effective fast track, give the software of an appropriative design and imitate analysis unifinication according to the specific characteristic development of some product namely. This software support shows some, mature CAD and CAE skill, just undertake 2 times a few developing the work on its foundation, can avoid higher development cost so. Software needs to input less product information data by technologist only, if make forging plan,can finish, the job such as mould graph, and can make the input information that numeric imitate place uses automatically, define many technology program. Next, start simulation software automatically to undertake an analysis, give out the result below different technology condition and its rule, undertake optimizing to technology program then. We had been in the project that with the first heavy machinery group company cooperation studies to seal head figuration preliminary implemented the tentative plan above. Because numeric imitate technology designs the outstanding advantage of the respect in craft, it is sure to get applied extensively in producing production field, this is the inevitable result that the technology progresses. Use imitate technology to replace a tradition in technology design only the means by experience, can increase production effectively efficiency, improve product quality, this one understanding has become consensus in the developed country. In recent years, the software that abroad uses at analysing forge to cause form, caky process, heat treatment to analyse already entered commercial phase, some had entered Chinese market. These software and domestic software photograph are compared, waiting for a respect versatility, easily to have larger dominant position with the gender, but the price is quite high, and material library include only Euramerican wait for the material with commonly used country, do not agree with Chinese national condition. Combine a few advanced techniques of abroad so, develop as soon as possible agree with the numeric simulation software that domestic company uses is urgent affairs. But more important is will existing, application of mature numeric imitate technology arrives among actual production, this still strengthens cooperation between need yard officer. CNC Milling